Discover Golang Projects on Upwork with Vollna

IMPORTANT: We are strictly looking for an individual, dedicated contractor. No agencies, development firms, or subcontracting will be considered.

Currently acquiring an exclusively dedicated developer with strong US time zone familiarity. As a software firm, we are looking for a reliable partner who can manage several projects, including direct customer management and clear communication. Fluent English is a high value and strictly required.

Please note: If you are currently full-time engaged in another local job or cannot dedicate focused, overlapping hours to this project, this role is not for you. We need someone who can treat this as a primary priority.

Project Overview: We are looking for a talented full-stack developer to redesign/update a website (currently hosted on a standard domain registrar) and build a custom, multi-signer intake form with secure document upload capabilities. The core of this project is integrating direct, custom backend automations with a third-party Remote Online Notarization (RON) API and QuickBooks Online. No third-party automation tools (Zapier, Make, etc.) are permitted. All integrations must be built via custom, standalone backend code.

- Key Deliverables:
Frontend Intake Form: Clean, mobile-responsive design allowing secure file uploads and dynamic form fields based on the input signer count.
Direct Third-Party API Integration: Connect to the RON provider’s REST API to instantly initiate a session and securely pass files upon customer submission.
QuickBooks Payments SDK Integration: Implement secure credit card vaulting/tokenization at intake using the official QuickBooks Web Payments SDK (ensuring zero PCI-compliance liabilities on our end).
Admin Post-Session Billing Tool: Create a lightweight, secure, password-protected internal portal where the admin can input final signer and seal counts after a session concludes.
Automated Invoicing Engine: Calculate the final dynamic pricing via custom code upon admin submission, generate a line-item invoice in QuickBooks, automatically charge the vaulted card token, and trigger the official receipt to the client.

- Technical Requirements:
Proven experience with backend languages (Node.js, Python, PHP, or Go).
Deep familiarity with QuickBooks Online Accounting & Payments APIs (specifically tokenized card charges, OAuth 2.0 token refresh cycles, and invoice generation).
Strong understanding of REST APIs, webhooks, JSON payloads, and secure file handling over HTTPS.
Ability to deliver clean, documented, standalone code without external platform dependencies (e.g., deploying a lightweight containerized solution to Render, AWS, or similar).
How to Apply: To ensure you have read this entire post, please start your proposal with the word "DEDICATED".

- In your proposal, please include:
A brief example of a similar custom API integration you have built (specifically involving payment gateways or document workflows). - FYI We place great importance on honesty. Even if you lack relevant experience, welcome anytime provided you possess confidence and a solid technical background.

Your approach to managing the QuickBooks OAuth token refresh cycle to ensure the chain never breaks during server restarts.

Your estimated timeline and fixed-price or hourly rate for this scope.

We need a senior Go engineer who has built real production tools — not someone learning on the job. The system needs to handle concurrent provisioning requests, webhook events from cloud providers, and integrate with our existing Terraform and Kubernetes workflows.
Specific tasks:

Build a REST + gRPC API layer for infrastructure provisioning requests
Integrate with AWS SDK and GCP client libraries in Go
Design a job queue system for async provisioning tasks (we use Redis)
Write clean, testable Go code — we do thorough code reviews

Stack:

Go, gRPC, Redis, PostgreSQL, Kubernetes, AWS SDK, Terraform (for context)
You're a good fit if:

You've built CLI tools or internal platforms in Go
You understand Kubernetes operators or controllers
You've worked with cloud provider SDKs directly
You can own architecture decisions, not just implement tickets

Not a good fit:

If your Go experience is mostly tutorials or small CRUD apps
If you need daily hand-holding

I need a senior Golang Developer to undertake code review for codebase of about 5 microservices. Then value effort and cost taken to deliver the quality of work in the codebase

Lead AI-First Backend Engineer (Golang, Claude Code)

Workload: full-time, fully remote
Start: asap, but can be discussed
Duration: long-term cooperation
English: Strong proficiency in English (Upper-intermediate level or Advanced)!

Details:
- CRITICAL: AI-first delivery: proven, demonstrable experience using Claude Code or similar agentic AI tools is a hard must (specific examples expected on the application).
- Senior Golang Developer, 5+ years of experience; can potentially consider really strong candidates with 4 years of experience
- Hands-on engineering position
- Not a people-management role
- CRITICAL: Lead part: Demonstrable experience of leading delivery within a team: coordinating, breaking work down, representing the team in planning and stakeholder conversations, facilitating outcomes. Someone who has been the de facto tech lead in a squad for several years without ever holding the formal title is absolutely fine too.
- CRITICAL: Strong proficiency in English (Upper-intermediate level or Advanced)

Role description:
We are looking for a highly capable Lead AI-First Golang Engineer to join a project where you’ll build an AI tourism platform. This is not a traditional coding role. We don’t need coders; we need engineers who build features end-to-end using AI coding tools. You’ll use Claude Code and other AI tools to 10x your output, always thinking about how the product or feature you are working on benefits the user. Also, we have no QA team — you OWN the quality of what you ship!

Regarding Lead responsibilities:
● This is not a people-management role: no one-to-ones, no performance reviews, no coaching responsibilities.
● Every engineer involved in the project already owns their work end-to-end (IC + DRI), so this role is not about “more ownership”.
● A Lead is the spokesperson, coordinator, and facilitator for their pod, internally with product, design, and leadership, and externally with clients. You think product-first, contribute meaningfully in product planning sessions, and represent your pod in those rooms.
● You remain a hands-on backend engineer. The spokesperson, coordination, and facilitation work sits on top of your IC contributions, not instead of them. Expect the majority of your week to still be engineering.

What you’ll actually do:
● Own features end-to-end: from specs to deployment to fixing bugs
● Use Claude Code to generate Golang backend code
● Review AI output for quality and architectural fit
● Fix bugs to learn our codebase, then rapidly build new features
● Make quick decisions on what to build vs buy vs generate with AI
● Talk to customers when they report issues, and ship fixes the same day

Additionally, at the Lead level:
● Be the spokesperson for your pod, internally with PMs, designers, and leadership, and externally with clients and partners
● Coordinate work across the pod: break initiatives into chunks, sequence them, surface blockers, and facilitate hand-offs
● Represent your pod in product planning sessions and bring a strong product-driven point of view to scoping and trade-offs
● Join client meetings when needed to gather context, align on requirements, and report on delivery

Products you will build:
● Platform: data- and AI-focused features, internal tooling, agentic systems
● Integrations: API connections to supplier and business client platforms, data ingestion pipelines, LLM providers

Our stack:
● Backend: Go monorepo (no framework, 3+ services)
● Hosting: PaaS-managed containers, local setup fully mirrors production via Docker Compose
● Tools: Jaeger tracing, Betterstack (Logging, Alerting), Redis Async queue
● Databases: PostgreSQL, Redis
● AI tooling: Claude Code (mandatory)

You are a great fit if you:
● You think in features and architecture, and not in single lines of code
● Get frustrated when development takes weeks instead of days
● Can spot subtle bugs in AI-generated code quickly
● You ship fast, but always verify it actually works
● Have shipped real products that customers actually use
● Think “how can AI build this?” as your first instinct
● You’re energized by product planning sessions and have opinions about what the pod should build next, not just how
● You’re comfortable being the face of your pod, both in internal planning rooms and on calls with clients

Red flags (don’t apply if):
● You’ve never used Claude Code or similar AI coding tools
● You’re a perfectionist who loves to code
● You need detailed specs before starting
● You see AI as a threat rather than leverage
● You’re outside European/African time zones
● You’re looking for a people-management role with one-to-ones, performance reviews and career coaching, but that’s not what this is
● You want to lead a team in name but not be hands-on in the codebase
● You’d rather avoid client meetings or stakeholder-facing conversations
● You think product planning is someone else’s job and you just want the tickets handed to you

You must have:
● Ownership mentality with a strive for elegantly simple, high-quality solutions
● Strive for max quality — you test your own work thoroughly since we have no QA team; everything you ship MUST work
● Product mindset — you care about WHY we’re building something
● Proven experience using Claude Code — share specific examples
● Strong Golang experience — you’ll review AI’s code in these and you must understand how it works
● Passion for simple, secure, and observable systems that perform well even under massive load
● Ability to do on-call once in a while to help maintain our platform’s reliability & uptime
● Broad architectural knowledge of building modern full-stack applications
● Excellent spoken English and a good internet connection for daily video calls
● :warning: European or African timezones (±3 hours from CET)
● Available full-time (40 hours/week)

Required at Lead level:
● Multi-year experience leading a pod, squad or similar unit (this is a hard must, not a nice-to-have)
● A genuinely product-driven mindset: you think about user value and business outcomes before implementation
● Comfort facilitating and coordinating a pod without relying on formal authority
● Willingness and ability to take part in client meetings and act as the external face of your pod
● Strong spoken and written communication for planning sessions, stakeholder updates, and client conversations

Summary:
● AI-first delivery: proven, demonstrable experience using Claude Code or similar agentic AI tools is a hard must (specific examples expected on the application)
● Senior Golang Developer, 5+ years of experience; can potentially consider really strong candidates with 4 years of experience
● Hands-on engineering position
● Not a people-management role
● Lead part: Demonstrable experience of leading delivery within a team: coordinating, breaking work down, representing the team in planning and stakeholder conversations, facilitating outcomes. Someone who has been the de facto tech lead in a squad for several years without ever holding the formal title is absolutely fine too.

⚠️ Important:

Candidates who attach a CV to their application will be prioritized.

• Describe your recent experience with similar projects

I’m converting an Expense Tracker app from Next.js to React Native. Most of the app is done, but I’m facing an issue where the app fails to navigate after login and shows errors related to navigation/state handling (React Navigation / undefined function type error).

I need someone to quickly debug and fix the issue and ensure the app loads and navigates correctly.

Tech: React Native, React Navigation, Golang
Budget: $7 (fixed)
Timeline: ASAP

We are seeking an expert in AI training and programming with 7+ years of experience. The ideal candidate will have hands-on experience with AI training tools and a strong background in programming languages. Responsibilities include developing and implementing AI models, collaborating with cross-functional teams, and optimizing AI systems for performance. This part-time role requires a high level of expertise and the ability to work independently.

We are seeking an expert in Golang backend performance review and optimization for a short-term consultation. The ideal candidate will have a strong background in analyzing and enhancing backend systems, ensuring they are efficient and scalable. Responsibilities include identifying performance bottlenecks, suggesting improvements, and implementing optimizations. Experience with cloud platforms and containerization is a plus.

Looking for a senior Go language developer specializing in VPN to fix a bug in an iOS parent control app. The app intercepts traffic via MITM, and the developer should have experience with VPN technologies. The task involves diagnosing and resolving the issue to ensure smooth traffic interception.

• Do you have experience in developing VPN apps?

We are looking for a Senior Ethereum / Web3 Developer to join a blockchain infrastructure company building on Ethereum.

The company works in the Ethereum block building / MEV / DeFi infrastructure space, including block construction and lending-related systems.

This is a senior-only role. We are looking for candidates with strong Ethereum/Web3 experience, ideally with background in algorithmic trading, MEV, DeFi, low-latency systems, or blockchain infrastructure.

Location

The role is focused on Krakow, Poland.

Candidates should ideally be based in Krakow.
We may also consider strong candidates from other locations in Poland who can travel to Krakow regularly.

The company currently has team members who come to Krakow approximately once a month for several days.

Requirements
- 5+ years of relevant software engineering experience
- Strong experience with Ethereum / Web3 systems
- Deep understanding of blockchain infrastructure, transactions, mempool, MEV, validators/builders, or DeFi protocols
- Experience with algorithmic trading, trading systems, or financial infrastructure — strong advantage
- Strong backend engineering skills
- Ability to work independently as a senior contributor
- Comfortable working as a subcontractor / long-term contractor
- Must be able to work from Krakow regularly

Nice to Have
- Experience with block builders / searchers / MEV infrastructure
- Experience with Solidity / smart contracts
- Experience with Rust, Go, C++, or high-performance backend systems
- Experience with lending protocols or DeFi risk systems
- Prior experience in crypto trading, HFT, or market-making environments

Compensation
= Typical senior compensation range: $100K–$140K annual equivalent, depending on experience and fit.

= Engagement model: Sub-contractor / long-term contractor.

Important
Please apply only if you are:
= Senior-level
= Experienced in Ethereum/Web3
= Based in Krakow or able to travel there regularly
= Relevant to blockchain infrastructure / DeFi / algo trading work

**Title:**
Flutter / Go Developer Needed for Pre-Launch Marketplace App – Stripe Connect Experience Important

**Description:**
Hi,

We are looking for a reliable developer to help maintain, debug, and improve our pre-launch marketplace / live shopping app.

The project is already developed, but we need someone who can understand the existing codebase, fix bugs when necessary, improve current features, and support us as we prepare for launch.

Ideally, we would like to find someone who can become our main technical support person for the project and be available daily for communication, quick checks, improvements, and urgent debugging when needed.

**Current stack:**

* Flutter mobile app
* Go backend
* Supabase database
* Kotlin for the Android floating widget / overlay feature
* Client web checkout flow built with Go-rendered templates, HTML, CSS, JavaScript, and Stripe.js
* HTMX / Alpine.js may also be used in some parts of the web checkout

**Important experience:**
We especially need someone who understands marketplace payment flows, ideally with Stripe Connect or similar systems.

Experience with the following is important:

* Stripe Connect
* Connected accounts
* KYC / onboarding flows
* Marketplace checkout logic
* Platform fees / commissions
* PaymentIntent flow
* Payment status handling
* Split payment logic or marketplace fund distribution

**What we need:**

* Maintain the existing project
* Fix bugs when they appear
* Improve existing features
* Help with Stripe Connect / marketplace payment logic
* Support the client checkout flow
* Review and understand the current backend and database logic
* Be available daily for communication and support when needed
* Communicate clearly and regularly
* Be comfortable working on an early-stage startup product before launch

**Budget:**
We are pre-launch and working with a small starting budget, roughly around $100–$150/month depending on workload and availability. We are looking for someone who can be involved on a regular basis to help maintain, improve, and support the project as we move toward launch. Budget can increase later if the collaboration works well and the project grows.

**Ideal profile:**

* Strong Flutter experience
* Experience with Go backend
* Comfortable with Supabase
* Experience with Stripe Connect or marketplace payments
* Basic Kotlin / Android native knowledge is a plus
* Comfortable with HTML, CSS, JavaScript, and Stripe.js
* Familiarity with HTMX / Alpine.js is a plus
* Able to work independently
* Honest, responsive, and reliable
* Interested in joining an early-stage product before launch

Please apply only if you are comfortable with the starting budget, the early-stage nature of the project, and being available daily for communication or urgent support when needed.

When applying, please briefly tell us about your relevant experience, your availability, and whether you are comfortable with the starting budget.

Thank you.

Skills: JavaScript, Mobile App Development, Android, CSS, Golang, HTML, Database Development, Kotlin, Flutter, Payment Processing

We are FAR AI, a two-sided GPU compute marketplace. We are preparing for our Alpha launch and need an experienced engineer to deploy, configure, and fully hand over a production-grade customer support system built around Zammad (open-source helpdesk).
This is a complete technical build, not a Zammad plugin install. The system connects five email inboxes, three in-product ticket widgets, a Discord bot, SLA automation, CSAT surveys, a status page, and a knowledge base portal — all wired together before our Alpha go-live date.
You will own the full technical build and hand it over to our Head of Customer Experience and two L1 support agents, with documentation they can operate without you.

We're building an AI-native SaaS platform and looking for a highly pragmatic engineer who can ship fast, work directly with product ideas, and turn rough concepts into production features.

What You'll Do
Build and ship AI-powered SaaS features end-to-end
Work across Go backends, React frontends, and cloud-native infrastructure
Vibe code rapidly with modern AI tools (Claude Code, Cursor, ChatGPT, Goose, etc.)
Collaborate on product direction, not just implementation
Design APIs, integrations, workflows, and user experiences
Deploy and operate services in Kubernetes environments
Required Experience
Strong Golang experience
Strong React / TypeScript experience
Experience with Kubernetes (k3d, k3s, or production K8s)
Comfortable using AI coding tools daily
Ability to take a high-level idea and independently deliver a working solution
Experience building SaaS products from concept to production
Strong product intuition and customer empathy
Nice to Have
LLMs, agents, RAG, MCP, vector databases
Postgres, Redis, NATS
GitHub Actions / CI/CD
Multi-tenant SaaS architectures
Slack, GitHub, Jira, or enterprise integrations
What We're Looking For
Builders, not ticket takers
People who can move quickly with minimal oversight
Engineers who think about product outcomes, not just code quality
Strong written communication and ownership mindset
To Apply

Please include:

Links to products you've built
Examples of AI-assisted development workflows you use
Your experience with Go, React, and Kubernetes
A brief description of the most complex SaaS product you've shipped
Your hourly rate and weekly availability

Bonus: Include a short Loom video walking through a project you've built and explaining how AI accelerated your development process.

• What is your github?
• What harness, tools, workflow do you use for development?
• Can you work on US time?

We are looking for a small backend team (one or preferably two Golang developers who have already worked together), to develop an Event-Driven Automation Engine forour application.

The project is not a simple CRUD application.
We need to build a scalable automation engine based on:

* Go / Golang
* RabbitMQ
* MongoDB
* Docker
* Event-driven architecture
* Rule evaluation engine
* Command-based execution model
* Multi-tenant CRM architecture

## Project Context
The Automation Engine must allow CRM users to define rules such as:

“When an event occurs, and specific conditions are met, automatically execute one or more actions.”

Example:

When a ticket is created and priority is HIGH, assign it to a department, add a tag, or send a notification.

The first MVP will focus on the Ticket domain, but the architecture must be extensible to other CRM entities such as contacts, accounts, leads, conversations, tasks, and orders.

## Required Architecture

The system must follow this pattern:

Event → Decision → Action → Command → Execution → New Event

The Automation Engine will:

* consume events from RabbitMQ
* validate a standard event envelope
* load automation rules from MongoDB
* evaluate nested conditions
* translate matching actions into commands
* publish commands to RabbitMQ
* propagate correlationId and metadata
* handle loop prevention with automationDepth
* support retries, DLQ, structured logging, and future horizontal scaling

The Automation Engine must not directly execute business logic or update CRM data directly.

Domain services will consume commands and execute the actual business logic.

## Required Skills
Mandatory:
* Strong Golang backend development
* RabbitMQ or similar message broker experience
* MongoDB experience
* Event-driven / asynchronous architecture
* Docker / Docker Compose
* Clean architecture and modular code
* Unit and integration testing
* Structured logging
* Error handling, retries, DLQ
* Good written English for technical documentation

Nice to have:
* Workflow automation experience
* Rule engine experience
* Microservices architecture
* OpenTelemetry or distributed tracing

## Preferred Team
Golang backend developer focused on implementation and testing

Please specify if you are applying as:
* individual developer
* team of two developers
* agency

If you are applying as a team, please describe previous projects you completed together.

## MVP Scope
The first MVP should include:
* RabbitMQ event consumer
* Event Envelope validation
* MongoDB automation model
* In-memory automation cache
* Condition Engine with nested AND / OR logic
* Action Engine
* Command builder
* RabbitMQ command producer
* Basic Ticket action handlers
* Metadata propagation
* Loop control
* DLQ and retry strategy
* Structured JSON logs
* Docker deployment
* Unit tests


## First Milestone
The first milestone is:

ticket.created event
→ automation rule matched
→ condition evaluated
→ command generated
→ command published to RabbitMQ

Example command:
crm.ticket.command.assign.department

## Selection Process
Before assigning the full project, we will ask selected candidates to complete a paid technical assessment.

The assessment will consist of building a small Go service that consumes an event from RabbitMQ, evaluates a rule from MongoDB, and publishes a command to RabbitMQ.

Please do not apply if you are not comfortable with a short paid technical test.

## Please Include in Your Proposal

1. Your experience with Go microservices.
2. Your experience with RabbitMQ or Kafka.
3. Your experience with MongoDB.
4. An example of an event-driven system you built.
5. How you would structure this project in Go.
6. How you would implement nested rule evaluation.
7. How you would handle duplicate events.
8. Whether you are applying alone or as a team.
9. Your availability and estimated weekly capacity.
10. Links to relevant GitHub, GitLab, or portfolio examples.

## Engagement Model
We prefer to start with:

1. Paid technical assessment
2. Architecture alignment milestone
3. MVP implementation
4. Extension and maintenance phase

We value clean code, clear communication, and incremental delivery.

We are looking for an experienced Golang Developer and DevOps Engineer to design, develop, deploy, and maintain scalable backend applications and cloud infrastructure.

Responsibilities:

Develop and maintain backend services and APIs using Go (Golang).
Design and optimize microservices architectures.
Build and manage CI/CD pipelines.
Deploy and maintain applications in cloud environments such as AWS, Azure, or GCP.
Manage containerized workloads using Docker and Kubernetes.
Implement infrastructure as code using Terraform or similar tools.
Monitor system performance, reliability, and security.
Troubleshoot production issues and optimize system availability.

Required Skills:

Strong experience with Go (Golang).
Experience with REST APIs, gRPC, and microservices.
Proficiency with Docker, Kubernetes, and container orchestration.
Experience with CI/CD tools such as Jenkins, GitHub Actions, or GitLab CI.
Knowledge of cloud platforms (AWS preferred).
Experience with Terraform, Ansible, or other Infrastructure-as-Code tools.
Familiarity with Linux administration, networking, and security best practices.
Experience with monitoring and logging tools such as Prometheus, Grafana, ELK, or OpenTelemetry.

Preferred Qualifications:

Experience building highly available distributed systems.
Knowledge of database technologies such as PostgreSQL, MySQL, Redis, or MongoDB.
Understanding of DevSecOps practices and cloud security.

Please include relevant project experience, technology stack expertise, availability, and expected rate when applying.

We have a Go-based VICI monitor for strongSwan that exports metrics to Datadog. We'd like to get a code review and recommendations for hardening and improving the solution.

Areas we'd like reviewed include:

VICI socket connection management
systemd service hardening and security
Logging, log rotation
Overall Go and Linux best practices

Please let me know if you'd be interested in reviewing the code and providing recommendations.

Job Title: Principal Payments Architect & Lead Integration Engineer (Fiat, Web3, & Global Rails)
Location: [Remote / Hybrid / India]
Job Type: [Full-Time / Contract]
Experience Level: Lead / Principal (7+ years)

🚀 About the Role

We are building a highly disruptive, omni-channel transaction ecosystem that unifies traditional fiat infrastructure, instant retail networks, and decentralized digital asset liquidity. We are seeking a powerhouse Principal Payments Engineer to architect our multi-rail transactional backbone.

In this role, you will design the core routing matrices that seamlessly connect global card networks, cross-border banking systems (SWIFT), physical/cloud POS systems, instant domestic networks (UPI), and institutional Web3 On/Off-Ramp layers. If you can confidently map out a transaction path that touches a retail terminal, an NPCI switch, a Visa network, and an institutional crypto liquidity desk in under two seconds, this role is built for you.

🎯 Key Responsibilities

Multi-Rail Core Architecture: Design and scale a unified, highly idempotent transaction processing engine that handles complex routing across Cards, SWIFT, UPI, and Crypto rails.

Web3 On/Off-Ramp Engineering: Build deep, high-throughput integrations with institutional crypto platforms like BVNK and Binance (Binance Pay / Exchange Core APIs) for real-time asset conversion, automated order book execution, and stablecoin settlements ($USDT$, $USDC$).

Global Fiat & Network Connectivity: Architect and manage direct processing-level integrations with international card schemes and international banking networks using modern core financial messaging standards.

Instant Payments & Hardware: Drive the development of UPI frameworks (dynamic QR codes, intent flows, collect requests) and physical/smart Android POS terminal applications (peripheral synchronization, offline capabilities).

Automated Clearing & Reconciliation: Construct multi-currency, double-entry financial ledgers capable of real-time currency conversion, gas fee optimization, bank settlement clearing, and automated dispute/chargeback processing.

Ironclad Security & Compliance: Enforce industry-standard compliance across both traditional and Web3 ecosystems (PCI-DSS Level 1, PA-DSS/PCI-SSF, Crypto Travel Rule/VASP, AML, and automated KYC pipelines).

🛠️ Technical Requirements & Deep-Dive Stack

1. Financial Messaging & Core Networks (Crucial)

Card Networks (ISO 8583): In-depth knowledge of ISO 8583 messaging protocol variants for payment routing, clearing, authorization, and settlement frameworks. Deep understanding of 3D Secure (3DS), card tokenization, and HSM key management (DUKPT).

SWIFT Network (ISO 15022 / ISO 20022): Expert-level experience with international banking messaging. Must have hands-on experience parsing, generating, and validating ISO 15022 (MT103, MT202) and migrating/architecting ISO 20022 (MX structures: pain, pacs, camt) for cross-border treasury movements.

UPI Infrastructure: Direct engineering experience interfacing with NPCI frameworks, managing Virtual Payment Addresses (VPAs), transaction polling, and sub-second webhook callback matching.

POS Hardware & Specs: Deep knowledge of EMVCo specifications, L1/L2/L3 certification pathways, and contactless (NFC) payment kernels built into smart Android/Linux terminals.

2. Crypto & Exchange Infrastructure

Liquidity Integration: Proven experience integrating with Binance API/Webhooks (Spot/Margin trading desks, liquidity pools, order books) and institutional payment rails like BVNK for real-time B2B settlements.

On/Off Ramp Orchestration: Strong understanding of blockchain custody solutions (e.g., Fireblocks, Copper) or smart contract interaction (Solidity/Rust) across EVM and non-EVM layers to handle digital asset settlement pipelines.

Risk Management: Experience building systems to mitigate slippage, handle gas optimization, and hedge liquidity volatility risks during order matching.

3. Engineering & Distributed Systems

Backend Frameworks: Master-level capabilities in a strongly typed, highly concurrent backend ecosystem: Go (Golang), Java, Rust, or C# .NET Core.

Database & Ledger Management: Deep experience with PostgreSQL or MySQL tuned for extreme ACID compliance, transaction isolation, and immutable append-only ledgers.

Message Streaming: Real-world reliance on message brokers such as Apache Kafka or RabbitMQ to securely orchestrate multi-step, asynchronous processing flows (e.g., initiating a SWIFT transfer or Crypto Off-Ramp instantly after a card authorization).

💼 Behavioral & Security Mindset

Defensive Engineering: You treat every network call as potentially compromised. You inherently architect against race conditions, replay attacks, double-spending, and partial state drops.

Root-Cause Investigator: The ability to calmly dive into distributed tracing logs and isolate why a cross-border settlement failed between an on-premise POS machine, an acquiring bank, and a crypto liquidity provider.

Regulatory Adaptability: Comfortable collaborating with compliance teams to dynamically adapt core codebases as global fiat, banking, and crypto regulatory frameworks evolve.

• Describe your recent experience with similar projects
• Please list any certifications related to this project
• Include a link to your GitHub profile and/or website
• What frameworks have you worked with?
• Describe your approach to testing and improving QA

Senior Backend Engineer — Trading Platform API Integration

Context
We need a senior TypeScript backend engineer to wire up the missing pieces, mainly a third-party broker integration. Full details under NDA on the first call.
Already in production

Dashboard: Next.js 16, React 19, Tailwind v4 — 8 refactored pages
Auth & payments: Supabase Auth, Stripe, Sumsub KYC
Risk engine: Rust, running in production
Infra: Docker Compose on a dedicated server, Traefik SSL, Postgres + TimescaleDB, Redis, Centrifugo (WebSocket), Sentry
CI/CD: GitHub Actions, staging + prod (currently degraded)
Legal, branding, domain, transactional emails: done

Scope
1. Broker API integration (~60%)
We have REST + WebSocket access to a major broker. You'll:

Build OAuth flow + encrypted token storage with refresh logic in Postgres
Implement master-level account provisioning via REST
Wire WebSocket sync: push account state events (riskStatus, cashBalance, positions, fills) to the equity_history table
Build reconnection logic (exponential backoff, idempotent)
Handle rate limits (429 + penalty ticket mechanism)

2. Risk rule wiring (~20%)

Detect breach events (daily loss, max drawdown, profit target)
Trigger force-liquidation via REST on breach
Update DB state for the UI
Account reset endpoint

3. CI/CD fix (~10%)
deploy.yml is failing on git fetch from the prod server (expired auth token). Renew via SSH deploy key (preferred) or PAT rotation. Restore staging + prod paths.
4. Observability (~10%)

Structured logging for the integration layer
Sentry alerting on breach events
Health endpoint + basic metrics
Document the data contract with the Rust engine

Stack
TypeScript strict · Next.js 16 API routes (App Router) · Supabase (Postgres) · SWR · Docker Compose · GitHub Actions · Sentry · Centrifugo · read-only exposure to a Rust engine
Requirements

5+ years backend / full-stack TypeScript
WebSocket + REST integration at scale (1000+ concurrent connections in production)
Postgres: schema design, transactions, query optimization
Strong async patterns, retry logic, idempotency
Prior work handling money (broker APIs, payment processors, exchanges, custodial APIs)
Docker + GitHub Actions
TypeScript strict — no any

Bonus (higher rate)

Trading platforms, brokerage tech, prop firms, or market data infrastructure
Order types, P&L, margin math, drawdown logic
TimescaleDB / time-series Postgres
Rust read-fluency (parse, not write)

Not in scope
Frontend, mobile, marketing site, customer support.
Engagement

3-month contract, $60-90/hr USD (DOE), 30-40h/week
100% remote, CET ± 4h overlap required
Possible conversion to full-time + equity after 3 months
Async-friendly: weekly 30-min sync, no daily standups
Start within 2 weeks

Process

20-min screen call (NDA first)
45-min technical deep-dive
60-min pair-programming on our codebase
References

Two weeks max from first call to offer.
To apply

One paragraph on a real-time or money-handling API integration you shipped (tech, what broke, how you fixed it)
Link to TypeScript code (repo, PR, or gist)
Confirm timezone (CET ± 4h)
Hourly rate

I read every proposal. Skip generic templates.
— Jules

Backend Engineer (Go / BMC Protocols) — Infrastructure Automation Platform

We are seeking a talented Backend Engineer with strong Go expertise to contribute to our core Server Management Platform. This platform is built for scalable infrastructure automation and device lifecycle management.

You will be assigned to one of three key engineering tracks, with ample opportunity for cross-track contributions as the platform evolves:

Track A — Discovery & Inventory: Multi-protocol device discovery (Redfish, IPMI, SNMP), hardware inventory APIs, and telemetry pipeline integration.

Track B — Provisioning & Monitoring: iPXE / HTTP Boot implementation for Linux/Windows, multi-OS image catalogues, and custom alerting engines.

Track C — Lifecycle / Cross-cutting: Console self-update workflows, feature gating/licensing, remote command execution (SSH, WinRM), and KVM (noVNC) integration.

What You’ll Do:

Contribute to a highly scalable server management platform.

Work on multi-protocol integrations and high-performance backend services.

Build systems supporting device discovery, provisioning, monitoring, and lifecycle management.

Must-Have Technical Skills:

Language: 4+ years of strong Go (Golang) experience. (We are also open to strong Python / Java / Rust engineers.

APIs & Data: Proficiency with REST & gRPC API design, PostgreSQL 16, and Redis 7.

Concurrency & Messaging: Experience with or exposure to NATS JetStream.

Debugging & Testing: Expert-level debugging (pprof, dlv, structured logging) and testing expertise (Unit, integration, table-driven tests, and Testcontainers).

Nice-to-Have (Bonus):

Exposure to Redfish, IPMI, SNMP, or BMC / out-of-band management.

Experience with iPXE, cloud-init, or kickstart (Track B).

Experience with WebSockets, WinRM, or SSH-streaming (Track C).

If you love low-level infrastructure, hardware automation, and building rock-solid backend services in Go, we’d love to hear from you! Please highlight your experience with Go and infrastructure/network protocols in your proposal.

Best of Luck

• Describe a complex backend system you built using Go. How did you handle high-concurrency or performance tuning (e.g., using pprof, dlv, or table-driven testing)?"
• This role involves bare-metal server management. What is your experience with low-level network or hardware automation protocols such as Redfish, IPMI, SNMP, or gRPC?
• Have you worked with NATS JetStream or similar message brokers/event streaming platforms? How did you ensure data consistency and reliability in that setup?
• What is your experience with network booting (iPXE, HTTP Boot) or remote command execution (SSH streaming, WinRM)?

Backend Engineer (Go / BMC Protocols) — Infrastructure Automation Platform

We are seeking a talented Backend Engineer with strong Go expertise to contribute to our core Server Management Platform. This platform is built for scalable infrastructure automation and device lifecycle management.

You will be assigned to one of three key engineering tracks, with ample opportunity for cross-track contributions as the platform evolves:

Track A — Discovery & Inventory: Multi-protocol device discovery (Redfish, IPMI, SNMP), hardware inventory APIs, and telemetry pipeline integration.

Track B — Provisioning & Monitoring: iPXE / HTTP Boot implementation for Linux/Windows, multi-OS image catalogues, and custom alerting engines.

Track C — Lifecycle / Cross-cutting: Console self-update workflows, feature gating/licensing, remote command execution (SSH, WinRM), and KVM (noVNC) integration.

What You’ll Do:

Contribute to a highly scalable server management platform.

Work on multi-protocol integrations and high-performance backend services.

Build systems supporting device discovery, provisioning, monitoring, and lifecycle management.

Must-Have Technical Skills:

Language: 4+ years of strong Go (Golang) experience. (We are also open to strong Python / Java / Rust engineers.

APIs & Data: Proficiency with REST & gRPC API design, PostgreSQL 16, and Redis 7.

Concurrency & Messaging: Experience with or exposure to NATS JetStream.

Debugging & Testing: Expert-level debugging (pprof, dlv, structured logging) and testing expertise (Unit, integration, table-driven tests, and Testcontainers).

Nice-to-Have (Bonus):

Exposure to Redfish, IPMI, SNMP, or BMC / out-of-band management.

Experience with iPXE, cloud-init, or kickstart (Track B).

Experience with WebSockets, WinRM, or SSH-streaming (Track C).

If you love low-level infrastructure, hardware automation, and building rock-solid backend services in Go, we’d love to hear from you! Please highlight your experience with Go and infrastructure/network protocols in your proposal.

Best of Luck

• Can you describe your experience with Go (Golang) in production environments?
• What is your experience with REST and gRPC API design?
• Have you worked with pprof, dlv, or structured logging for debugging performance bottlenecks in Go?
• This role heavily involves server management and out-of-band protocols. Do you have hands-on experience with Redfish, IPMI, SNMP, or working with BMCs? If yes, please summarize your experience.

We're looking for a senior backend engineer with deep experience in distributed systems, constraint-based scheduling, and real-time allocation logic. This is not a ticket-implementation role — you'll work with architecture SMEs to shape system design, produce design docs, and own hard problems end to end.
Requirements

10+ years backend systems experience with strong distributed systems fundamentals
Experience building scheduling, allocation, or slot-filling systems
Comfortable designing constraint-based engines with complex prioritization logic
Strong relational and time-series data modeling (PostgreSQL preferred)
Timezone-aware scheduling including DST edge cases and UTC offset math
Proficiency in Node.js, Python, or Go — strong concurrency fundamentals required
Strong written communication — you'll produce design docs, not just code

Technical Skills

Constraint satisfaction, priority queues, and slot-filling algorithm design
Pacing algorithms for delivery and budget enforcement
Event sourcing, structured audit logging, and per-decision observability (Datadog or equivalent)
REST API design with OpenAPI/Swagger; webhook or event-driven architecture
Feature flag infrastructure and shadow mode / parallel run testing patterns

Nice to Have

Graph data modeling
Share-of-voice, frequency capping, or programmatic integration experience
VAST/VMAP familiarity

Please include examples of distributed systems or scheduling work you've owned in your application

We are building a next-generation payments platform focused on simplifying how users manage, move, and spend digital assets through a seamless financial experience.

Our platform combines account management, transaction processing, payment infrastructure, ledger systems, and integrations with external financial services. We are looking for a highly experienced Backend Engineer to help design and build scalable systems that power the core platform.

Responsibilities
- Design and develop backend services and APIs
- Build scalable transaction processing systems
- Develop ledger and account management infrastructure
- Integrate third-party payment and financial service providers
- Optimize system performance, reliability, and security
- Collaborate closely with product, design, and engineering teams
- Participate in architecture and technical decision-making
- Write clean, maintainable, and well-tested code

Required Skills
- Strong experience with Node.js, TypeScript, Python, Java, or Go
- Experience building scalable backend systems
- Strong API design and integration experience
- Experience with PostgreSQL, MySQL, or similar databases
- Understanding of distributed systems and system architecture
- Experience with cloud platforms such as AWS, GCP, or Azure
- Strong problem-solving and communication skills

Nice to Have
- Experience in fintech, payments, banking, or financial products
- Experience with transaction processing systems
- Experience with ledger or accounting systems
- Knowledge of security best practices and compliance requirements
- Startup experience and ability to work in fast-paced environments

What We're Looking For
We are looking for someone who can think beyond implementation and contribute to architecture, scalability, and product decisions.
You should be comfortable taking ownership of complex technical challenges and working directly with founders and stakeholders.

To Apply
Please include:
- A brief introduction
- Relevant backend or fintech experience
- Examples of systems you have built
- GitHub
- Your hourly rate
- Weekly availability

We are open to long-term collaboration for the right candidate and are looking for engineers who enjoy building impactful products from the ground up.

Golang Software Engineer (Full-Time, India, Remote) - Workflow Automation Platform

About Us
We are building a modern workflow automation platform focused on execution, debugging, observability, and control of business workflows.

Unlike traditional workflow tools, we're focused on helping teams understand what happened during execution, debug issues quickly, and safely re-run workflows when needed.

We're looking for a strong Golang engineer who enjoys building backend systems from scratch and wants significant ownership over architecture and implementation.

What You'll Build

You will work directly with the founders to design and build core platform capabilities, including:
Workflow execution services
REST APIs
Execution state management
Scheduling and orchestration components
PostgreSQL-based persistence layers
Observability and debugging capabilities
Integration infrastructure

This is a hands-on engineering role with significant influence on technical decisions.

Required Experience
3–6 years of software engineering experience
At least 2 years of Golang experience in production
Strong understanding of:
REST APIs
Microservices
PostgreSQL
Concurrency in Go
Distributed systems fundamentals
Experience deploying services in AWS

Nice to Have
Kafka
Event-driven architectures
Temporal
Workflow engines
Docker

Engagement
Full-time
Remote within India
Initial 6-12 month engagement
Potential long-term opportunity based on company growth and mutual fit

Compensation
Monthly payments
Performance-based increases as the team grows

Screening Process
Resume review
30-minute founder discussion
90-minute technical interview
Final discussion

No take-home assignments.

To Apply
Please include:
Years of Golang experience
Largest production system you've worked on
Current compensation
Expected compensation
Notice period
Location within India

Screening Questions
How many years of Golang experience do you have?
Have you built production APIs in Go?
Describe a scalability or performance issue you solved.
Have you worked with PostgreSQL in production?
What is your notice period?
Are you available for full-time work during Indian business hours?
What is your expected annual compensation in INR?

Hi [Name] — I'm a senior engineer (ex Goolgle 6+ years) looking to seriously level up how I build with generative-AI tools (Claude Code, Cursor, etc.). Not
▎ looking for someone to ship code for me — I want to pair live and learn how a daily power-user actually works: the high-leverage workflows
▎ and the real limitations.
▎
▎ It's language-agnostic; the craft is what matters. $60–100/hr, starting with a short paid trial (~2 sessions), ongoing if we click.
▎
▎ If that sounds interesting: what tools do you use daily, and what's one limitation you've hit that changed how you work? Would love to set
▎ up a first session.

Senior Backend Developer Needed for Digital Gaming Platform & Custom P2P Wallet Integration (Node.js / Go)

We are looking for a highly skilled Senior Backend Developer (or a small specialized team) to develop a custom digital gaming platform from scratch. The core architecture requires building high-performance, secure management dashboards and integrating third-party gaming/sports data APIs.

Key Responsibilities:
- Custom Backend Development: Build a highly scalable and secure backend using Node.js or Go.
- Database Architecture: Design and implement a hybrid database structure using PostgreSQL and Redis.
- Third-Party API Integration: Seamlessly integrate third-party Casino Aggregators and Sportsbook live data feeds via REST APIs and WebSockets.
- Agent P2P Wallet System: Develop a multi-level agent wallet management system that supports manual balance distribution and transaction tracking.
- Admin Dashboard: Build a comprehensive central admin control panel to manage users and set risk parameters.

Project Type: Fixed-price / Milestone-based.

Skills: JavaScript, Golang, Node.js, Socket IO, PostgreSQL, Redis, React.js, Backend Development, Security, API Integration

We are seeking an AI engineer to complete our company's main project. The role involves working with Golang and Python to build a system that requires customization. The ideal candidate will have experience in system architecture and development, with a focus on AI technologies. This is a part-time engagement expected to last 1 to 3 months.

• Describe your recent experience with similar projects
• Include a link to your GitHub profile and/or website
• What frameworks have you worked with?
• Describe your approach to testing and improving QA

I have a Go (Gin + GORM) backend service that needs some urgent fixes and improvements.

Tasks

•⁠ ⁠Fix bugs in existing REST API endpoints
•⁠ ⁠Improve error handling and logging
•⁠ ⁠Optimize database queries and add missing indexes
•⁠ ⁠Add authentication/authorization improvements for a few routes

This should be a quick turnaround job for an experienced Golang developer.

I need an experienced full stack developer to build a web app with two components: a private admin dashboard and a public-facing content page.

Full details shared under NDA after initial interview.

What I can share at this stage:

The app involves scheduled automation, a one-click publish flow, and automatic email and SMS notifications to subscribers.

I have a working prototype, a complete brief, and all assets ready to hand over immediately after we sign a simple NDA.

Tech stack: Next.js, Supabase, Vercel, Claude API, Resend, Twilio.

Timeline: 3-4 weeks.

Start date: Immediately.

To be considered, please share two live Next.js projects you have shipped.

• How would you structure a database for an app with scheduled automation, a publish workflow, and subscriber notifications?

We have a Golang SaaS backend with Stripe already integrated. A few payment-related bugs have come up that need investigation and fixing, along with a couple of general backend issues.

Looking for a senior Golang developer who can jump into an existing codebase, find the root cause, and deliver clean fixes. Stripe API knowledge is required.

Please share relevant experience in your proposal

About Us & Project Background
We are PT Personel Alih Daya Tbk, a large-scale outsourcing company managing over 40,000 manpower. Currently, our operational data—including payroll, invoices, fraud tracking, and employee history—is managed manually across scattered Google Drives, Sheets, and XLSX/TSV files. To eliminate human error and accelerate data reconciliation, we are initiating the development of AXIS (Automated Analytics & Information System), a centralized internal data platform to serve as our single source of truth.


Scope of Work (MVP Phase)
We are looking for an experienced Full-Stack Developer or Web Development Agency to build our MVP from scratch. The scope of work includes:
1. System Design & Architecture: Designing technical systems including database, API layer, UI, and storage.
2. Data Ingestion Module: Developing multi-format file upload (XLSX, CSV, TSV) and Google Sheets integration via URL/OAuth.
3. Mapping & Validation Engine: Creating a user interface to map source columns to standard AXIS fields with automatic data validation rules.
4. Data Storage Layer: Setting up a centralized relational database with partition support per operational period.
5. Schema Management UI: Building an interface for data engineers to create, edit, and manage database tables dynamically.
6. Query Interface UI: A form-based filtering UI for non-technical business users to easily query and export data to XLSX/CSV.
7. RBAC & Security: Implementing Role-Based Access Control across 4 primary user roles.
8. Audit Trail & Logging: Setting up an end-to-end user activity log and a dedicated audit dashboard.

Preferred Tech Stack
We highly recommend the following stack, though we are open to well-justified alternative frameworks:
- Frontend: Vue.Js.
- Backend: Golang or Spring Boot
- Database: PostgreSQL (supporting table partitioning and JSONB).

Project Timeline & Requirements
- Target Duration: Maximum of 3 months from kick-off to production deployment.
- Language: The application interface will be delivered primarily in Indonesian.
- Compliance: The selected vendor/freelancer must sign an NDA and a data processing agreement.

If your team has extensive experience building scalable internal business tools, automated data pipelines, or ingestion engines, please apply with your relevant portfolio and a brief structural overview of your proposed approach.