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We are seeking an experienced Full-Stack Web Developer to create an appointment booking and client management web application. The platform should enable customers to browse services, book appointments, and manage bookings. The admin dashboard should allow our team to manage appointments, customers, and services. We need a developer who can handle both frontend and backend development, delivering a clean, responsive, production-ready application.

I’m building a platform for one-person companies where a founder describes the business they want and AI agents run the rest. An MVP exists and the concept is proven, but I need help getting to a working alpha that runs end-to-end reliably and is stable enough for a small group of real users.
Scope of work
- Close the gaps in the existing MVP so the full end-to-end flow works unattended (start to finish).
- Expand platform scope with more agent capabilities, more roles, and support for more kinds of business.
- Improve reliability so the multi-agent system keeps running without someone watching it, including failure recovery and handoffs between long-running agents.
- Add enough hardening and monitoring to safely let outside users into the system.
- Implement founder-facing product polish in the existing Next.js/React frontend.
Read more
Additional information
- The MVP/core pieces are already built and the concept has been demonstrated, but it does not yet run end to end reliably.
- Frontend is Next.js/React.
Company details
- A platform for one-person companies where a founder describes the business they want and AI agents handle functions like marketing, sales, engineering, design, finance, customer support, research, and writing using real tools/accounts, escalating only human decisions.

About us

We are a healthcare technology company in Hong Kong. Our platform lets patients find and book appointments with clinics and doctors. It also includes portals for clinic administrators and practitioners, plus telehealth and payments.

The platform was built by a professional development agency, not assembled with AI tools. The code is properly structured. Documentation exists but is limited, so you should be comfortable working out how parts of the system function by reading the code.

We are now moving development in-house and you would take ownership of the platform.

Stack

Backend: Node.js and Express
Frontend: React
Infrastructure: Azure, Docker, Nginx
Integrations: Stripe, SMS for one-time passcodes, video calling, calendar sync
Multi-tenant: organisations contain practices, practices contain practitioners and patients. Four user roles with different permissions.

Your work

Build and ship backend features.
Manage the Azure environment: containers, Nginx, deployments, CI/CD, monitoring.
Review and finish features started by non-engineers on our team using AI tools. Their code often works but is not ready for production. You would fix it, test it, and merge it.
Keep tenant data separated. Users from one organisation must never see another organisation's data.
In your first month, write an assessment of the codebase: what works, what is weak, and what should be improved first.

Requirements

5+ years building Node.js and Express services in production.
Good React skills.
Azure experience in production: containers, networking, secrets, storage, CI/CD.
Docker and Nginx: you have configured and debugged both yourself.
Experience taking over a codebase built by another team.
Daily use of AI coding tools, and good judgement about when their output is wrong.
Confident with Git: branching, conflicts, reviewing other people's work.
Multi-tenant experience. You understand how data leaks between tenants and how to test for it.
Experience in healthcare, payments, or another regulated industry.
Strong communicator in written English. You explain problems clearly, ask questions early, and tell us when something is wrong.

Nice to have

HubSpot integration
Stripe, Twilio, WebRTC
Security testing: sessions, one-time passcodes, token replay
Moving a JavaScript codebase to TypeScript

Hours and timezone

Our team works Hong Kong hours (GMT+8). You do not need to be in Hong Kong, but you do need to overlap with our working day for at least [4] hours, every day.

In practice this means an early start if you are in Europe. A Central European engineer would begin around 07:00 their time to reach our afternoon. Timezones more than 6 hours behind Hong Kong will not work for this role.

Tell us in your application which hours you can commit to, in your own local time.

These items were the original list that needs addressing,

Page title
Meta descriptions
Heading tags
Image names
Alt text on images
Textual content
Keyword research
Schema markup
URL structure

The initial investment covers:

Subscription to professional SEO research platforms
UK keyword research and search opportunity analysis
Competitor research and market intelligence
Backlink and brand mention analysis
Technical website auditing
Search engine indexing and tracking setup
Performance benchmarking and baseline reporting
Ongoing ranking and visibility monitoring configuration

In addition to the software, this also includes allocating a dedicated person to the project who will continuously monitor the website's SEO performance, identify issues, review search engine updates, track ranking changes, and ensure everything is progressing as planned throughout the campaign.

This upfront setup allows us to establish a complete SEO workflow from day one and gives us accurate data to guide every optimisation decision moving forward.

Initial Investment

One-time SEO setup: $350 (Upfront)

Ongoing $100 /week

We have a store front tied into our marketing software. Our stack is (Vue/Vuetify/Vite)/(Firebase/Firestore)/Nodejs. Some pages are complete, the store front is not implemented, neither is the user view that shows past and saved orders. Object schema will be similar to GoHighLevel which is well documented. Looking to bring in someone to increase velocity. and take this over the finishline.

We’re looking for a Senior Full-Stack Developer to join our team and continue developing our existing Academy Management System and mobile app.

Main Requirements:

- Strong experience with Laravel, PHP, Vue.js, and JavaScript.
- Experience with APIs, databases, and third-party integrations.
- Previous experience with hybrid mobile app development is a plus.
- Ability to work with and improve an existing codebase.
- Strong problem-solving and communication skills.

You’ll work under the guidance of our Tech Lead, who will provide the technical direction and development approach.

I have an existing production website that currently has multiple bugs, performance issues, database connection/load problems, security concerns and outdated code.

I am looking for an experienced **full-stack development team/agency** to completely audit, rebuild and optimize the platform.

### Main Requirement

I want to migrate the existing PHP-based system to a modern and scalable stack:

* Node.js
* TypeScript
* React/Next.js
* MySQL or PostgreSQL
* Redis
* REST APIs
* Background jobs/queues where required

### Work Required

The selected team will need to:

1. Fully audit the existing PHP codebase and database.
2. Identify all bugs, security vulnerabilities and performance issues.
3. Understand and preserve the existing business logic and important functionality.
4. Rebuild the backend using Node.js + TypeScript.
5. Rebuild/improve the frontend with a modern responsive UI.
6. Rebuild and optimize APIs.
7. Optimize database queries, indexes and connections.
8. Fix excessive CPU/database usage and unnecessary API requests.
9. Implement proper authentication, authorization and rate limiting.
10. Optimize background jobs and cron processes using queues where appropriate.
11. Improve the admin panel and user dashboard.
12. Test the complete system before production deployment.
13. Safely migrate existing users/data.
14. Deploy the new system to production.

### Important

This is **not just a simple bug-fixing project**. I want a proper professional rebuild after understanding the existing system.

I want the final platform to be:

* Fast
* Secure
* Scalable
* Stable
* Mobile responsive
* Easy to maintain
* Ready for higher traffic

### Developer/Team Requirements

Please apply only if you have strong experience with:

**Node.js, TypeScript, React/Next.js, MySQL/PostgreSQL, Redis, REST APIs, Linux/VPS and production web applications.**

Experience with **PHP-to-Node.js migration, SaaS dashboards, payment/wallet systems, third-party APIs and high-volume API platforms** is highly preferred.

Please share:

* Previous similar projects
* Portfolio/GitHub
* Team size
* Estimated timeline
* Fixed or estimated total price
* Post-development support

I am looking for a **complete development team at a reasonable cost**, not just a single developer who will apply temporary patches.

Hello!

Looking for an experienced backend developer to contribute to an open-source GitHub project.

You will identify a good, active GitHub repository yourself (AI/ML/LLM/backend related), review its open PRs/issues, and work on solving, improving, and getting PRs merged/closed.

Looking for someone who can:

* Find worthwhile open-source repos and issues independently
* Understand an unfamiliar codebase quickly
* Review and improve PRs
* Write production-quality Python/backend code
* Work with AI/ML/LLM systems and GitHub workflows

When applying, please share the GitHub repo you would recommend working on, why you chose it, and examples of your previous GitHub contributions.

Required: Python, Git/GitHub, fullstack, backend development, AI/ML/LLM experience, and strong code-review skills.

Sai K.

Hello!

Looking for an experienced backend developer to contribute to an open-source GitHub project.

You will identify a good, active GitHub repository yourself (AI/ML/LLM/backend related), review its open PRs/issues, and work on solving, improving, and getting PRs merged/closed.

Looking for someone who can:

* Find worthwhile open-source repos and issues independently
* Understand an unfamiliar codebase quickly
* Review and improve PRs
* Write production-quality Python/backend code
* Work with AI/ML/LLM systems and GitHub workflows

When applying, please share the GitHub repo you would recommend working on, why you chose it, and examples of your previous GitHub contributions.

Required: Python, Git/GitHub, fullstack, backend development, AI/ML/LLM experience, and strong code-review skills.

Sai K.

We are looking for an experienced MERN Stack Developer to build an AI-powered Retrieval-Augmented Generation (RAG) system for our business.

The system will allow users to upload business documents and receive accurate, context-aware answers through an AI chat interface. The developer will handle frontend and backend development, AI integration, testing, and deployment.

Key Responsibilities:
* Build a responsive chat interface using React.js.
* Develop backend APIs using Node.js and Express.js.
* Store application and user data in MongoDB.
* Integrate OpenAI or another suitable LLM.
* Implement document uploading and text extraction.
* Generate embeddings and integrate a vector database.
* Develop a reliable document-based RAG workflow.
* Add authentication and conversation history.
* Include relevant source references in AI responses.
* Deploy the completed application.
* Provide clean code and basic technical documentation.

Required Skills:
* React.js, Node.js, Express.js, and MongoDB
* OpenAI API, LangChain, or LangGraph
* RAG architecture and prompt engineering
* Vector databases such as Pinecone, Qdrant, Weaviate, or Chroma
* REST APIs and third-party integrations
* Git and cloud deployment
* Python experience is a plus

Deliverables:
* Functional AI-powered RAG application
* Document uploading and processing
* AI chat interface with source-based responses
* Authentication and conversation history
* Deployed application
* Source code and setup documentation

We are seeking a skilled mobile app developer to integrate AI features into our existing app. The ideal candidate will have experience with AI technologies and a strong understanding of mobile app development. Responsibilities include designing, developing, and testing AI-driven features to enhance user experience. Familiarity with iOS and Android platforms is essential.

We’re seeking a full stack developer to build and maintain web applications using the MERN stack. The role includes developing responsive user interfaces, creating backend services, and integrating AI/LLM capabilities into application workflows. You’ll collaborate with our team to deliver scalable, reliable solutions and support ongoing improvements to existing systems. Experience working on end-to-end web projects and translating requirements into functional features is important.

We’re looking for an experienced Full Stack Engineer to join our development team and work on web applications using React, Next.js, Node.js, and Express.
The ideal candidate should be comfortable working across both frontend and backend and be able to take ownership of features from development to deployment.

Responsibilities—
Develop and maintain web applications using React and Next.js
Build scalable backend APIs using Node.js and Express
Integrate REST APIs and third-party services
Work with databases and backend architecture
Fix bugs and improve application performance
Write clean, reusable, and maintainable code
Test and deploy new features
Collaborate with the team and provide technical solutions

Requirements——
Strong experience with React, Next.js, Node.js, and Express
Good understanding of REST APIs and database integration
Experience with Git and deployment workflows
Strong problem-solving skills
Ability to work independently and meet deadlines

We are looking for an experienced **Full Stack Developer** with strong expertise in **Flutter** and **Node.js (Express.js)** to enhance our existing fishing application.

The app is already built and functional. We are now adding intelligent features that will help users make better fishing decisions based on real-time weather conditions and AI-driven recommendations.

## Tech Stack

* Flutter (Android & iOS)
* Node.js
* Express.js
* REST APIs
* AI API Integration (OpenAI, Gemini, Claude, or similar)
* Git

## Scope of Work

### 1. Weather Module

Develop a new weather module that provides real-time weather information relevant to fishing, including:

* Current weather conditions
* Hourly and daily forecasts
* Wind speed and direction
* Temperature
* Humidity
* Rain probability
* Atmospheric pressure
* Sunrise and sunset
* Weather alerts
* Any additional weather metrics useful for fishing

The weather information should be presented in a clean, user-friendly interface.

### 2. AI Fishing Assistant

Integrate an AI-powered assistant that analyzes weather conditions and helps users determine the best fishing opportunities.

The AI should be able to:

* Analyze current weather conditions
* Recommend whether it is a good time to fish
* Suggest the best fishing times during the day
* Explain why the conditions are favorable or unfavorable
* Recommend suitable fishing techniques or bait (when possible)
* Answer fishing-related questions in a natural, conversational way

## Backend Responsibilities

* Develop REST APIs using Node.js and Express.js
* Integrate third-party Weather APIs
* Integrate AI APIs (OpenAI, Gemini, Claude, etc.)
* Implement secure API endpoints
* Ensure proper validation and error handling
* Write clean, scalable, and maintainable code
* Document the APIs

## Flutter Responsibilities

* Integrate the new backend APIs
* Build responsive and polished UI screens
* Handle loading, empty, and error states gracefully
* Write reusable and maintainable code
* Ensure smooth performance across Android and iOS

## Requirements

* Strong experience with Flutter
* Strong experience with Node.js and Express.js
* Experience integrating AI APIs
* Experience working with Weather APIs
* Experience working with existing codebases
* Knowledge of REST API development
* Git version control
* Good communication skills
* Ability to deliver production-quality code

## Nice to Have

* Experience building outdoor, navigation, or location-based applications
* Experience with maps and geolocation
* Knowledge of weather forecasting services
* Understanding of clean architecture and scalable application design

## Deliverables

* Fully integrated Weather module
* AI Fishing Assistant
* Backend APIs
* Flutter frontend integration
* Production-ready, tested code
* Source code committed to our Git repository
* Basic documentation for setup and deployment

## To Apply

Please include the following in your proposal:

1. Your experience with Flutter.
2. Your experience with Node.js and Express.js.
3. Examples of AI features you've developed.
4. Examples of weather API integrations.
5. Links to similar apps or GitHub repositories.
6. Your estimated timeline.
7. Your hourly rate or fixed-price quote.

We are looking for a developer who writes clean, scalable code and can become a long-term development partner for future enhancements.

Website with no of landing pages for my yoga studio

We’re looking for a skilled Full-Stack Web Developer to join our team and help build, improve, and maintain modern, scalable web applications.

The ideal candidate should have strong experience with React, Next.js, Node.js, and MongoDB, with a good understanding of both frontend and backend development.

What You’ll Do

* Build responsive and modern web applications using React.js and Next.js
* Develop scalable backend services and REST APIs using Node.js and Express.js
* Design and integrate databases using MongoDB/Mongoose
* Integrate third-party APIs and services
* Implement authentication, authorization, and secure API endpoints
* Optimize applications for performance, scalability, and SEO
* Debug existing applications and resolve technical issues
* Collaborate with designers and other developers to implement features
* Write clean, reusable, maintainable, and well-documented code
* Deploy and maintain web applications in production

Requirements

* Strong experience with React.js
* Strong experience with Next.js
* Good knowledge of Node.js and Express.js
* Experience with MongoDB and Mongoose
* Solid understanding of REST APIs
* Experience with Git/GitHub
* Understanding of responsive web design
* Good knowledge of JavaScript/TypeScript
* Ability to work independently and meet deadlines
* Strong problem-solving and communication skills

Nice to Have

* Experience with Tailwind CSS
* Experience with Socket.io/WebSockets
* Experience integrating payment gateways such as Paystack or Flutterwave
* Experience with cloud deployment and services
* Understanding of SEO and web performance optimization

To Apply

Please share:

1. A brief introduction about yourself
2. Examples of web applications you have built
3. Your experience with React, Next.js, Node.js, and MongoDB
4. Your availability and preferred hourly rate

We’re looking for someone who can become a reliable long-term developer and contribute to building high-quality web products.

We need a full stack developer to fix and test web and app issues, improve performance, and support ongoing development. The work includes troubleshooting bugs, refining user flows, and helping maintain reliable functionality across projects. You should be comfortable working independently, communicating clearly, and delivering dependable updates. Experience with web and app development is important, along with the ability to test changes thoroughly before deployment.

We’re looking for an experienced Node.js Backend Developer to help with a small task in an existing web application.

The backend is already built with Node.js / Express.js, but we need help integrating a third-party REST API and fixing a few issues with the current data processing flow.

The task includes:
Review the existing Node.js backend
Integrate one external REST API
Update the data processing logic
Add proper error handling and validation
Fix a few existing API response issues
Test the updated endpoints
Keep the existing architecture and code structure clean

Required skills:

Node.js, Express.js, JavaScript/TypeScript, REST API, MongoDB or PostgreSQL, Git.

This is a relatively small and clearly scoped task. We’re looking for someone comfortable working with an existing codebase who can quickly understand the backend logic and implement the required changes without unnecessary rebuilding.

Budget: $310 fixed price

I’ve never done anything like this before I’m trying to start a tech start up company. My first one is forge. A paycom style company operated completely by AI. I don’t know anything about AI or tech but I need someone to build my apps and websites looking for a quote

Hello!

i want to use whop as a payment processor on my shopify store, but can you connect zapier to it so everything works and the checkout works with al the prices etc

the order also needs to appear in ''orders'' so my supplier can fullfil it

just perfectly integrate zapier and whop on to the website

I am looking to redo my website. I am currently on Squarespace and I was told I should be using something better. I would like my website to be able to work better with Google ads I have a low score because I built it myself. I am open to switching to a new platform.

I am looking for someone who knows what they're doing and can help me get this set up correctly from the beginning adding all the tags in SEO and different things that need to be put into the website. I'm looking for someone who can help me get it all set up and then maybe as we go maybe they can help me add pages in or make changes here there in the future.

We are looking for an experienced React Native Full-Stack Developer to take over and further develop our existing cricket ground booking platform.

The app is already developed in React Native, so experience working with existing codebases is essential.

Hello!

i want to use whop as a payment processor on my shopify store, but can you connect zapier to it so everything works and the checkout works with al the prices etc

We are looking for a ReactJS developer to help fix bugs in our existing application. Your task will involve identifying and resolving issues related to React components, state management, and UI behavior.

If you're available and skilled in ReactJS bug fixing, we'd love to hear from you!

We're looking for an experienced Full-Stack Developer to take over and continue developing our existing e-commerce platform. We want a long-term technical partner who can own ongoing development and help us build out AI-powered features.

Your Responsibilities
Take over and get familiar with the existing React frontend and Node.js/MongoDB backend
Continuously develop new features and improve existing ones
Design and maintain APIs and third-party integrations
Improve performance, scalability, and code quality
Identify, debug, and fix issues across the stack
Work with us to plan and implement AI features (e.g. AI-assisted content generation, smart search/matching, personalised recommendations, data analysis)

Requirements
Several years of professional experience with React and Node.js
Strong experience with MongoDB (schema design, queries, performance)
Solid JavaScript/TypeScript skills
Experience building and maintaining REST/GraphQL APIs
Comfortable working in an existing, larger codebase
Confident with Git/GitHub


Nice to Have
Experience with AI/LLM APIs (OpenAI, Anthropic, etc.)
Experience with Next.js
Experience with search/matching systems
Cloud/server experience (AWS, Docker, CI/CD)

What We Offer
Long-term collaboration, not a one-off project
An established platform with room to grow
Freedom to bring ideas and shape the roadmap
Flexible working arrangement
Fair pay based on experience

To Apply, Please Include
A short overview of your React + Node.js/MongoDB experience
2-3 links to relevant projects
Your experience with AI/LLM technologies, if any

ABOUT THIS ROLE

This is a live product, not a prototype.

We are a Swiss software publisher. Our platform handles reservations and floor management for restaurants — real venues, real bookings, paying customers, running in production today.

We have two releases to ship: one in September, one on 1 January 2027. Both dates are firm. We are bringing in senior engineering capacity to get there, and we intend to keep working with the right person well beyond those dates.

What we offer is straightforward: a defined scope, direct contact with the decision-maker — no account manager, no committee, no three-day wait for an answer — and a codebase that already works and already earns.

What we ask is equally straightforward: that you can read someone else's code without insisting on rewriting it, that you tell us plainly when we are wrong, and that you hit dates.

If you are looking for a quick gig, this is not it. If you are looking for a client you can still be working with in two years, keep reading.


STACK

Backend — Node.js 18+, Express, MariaDB/MySQL (mysql2), JWT auth
Frontend — React + Vite
Payments — Stripe (Checkout Sessions, Customer Portal, webhooks)
Email — Nodemailer / SMTP
Hosting — Linux, SSH access, no container orchestration


FIRST ASSIGNMENT (paid, ~25-30 hours) — TECHNICAL AUDIT — STARTS THIS WEEK

We start every collaboration with one scoped, paid assignment.

Our platform has two reservation management views:
- a timeline/grid view (tables as rows, time slots as columns)
- a 2D floor-plan view (visual room layout)

The backend already exposes the required endpoints (rooms, tables, reservation move + move logs, availability slots). What we need is an honest technical assessment of the frontend and of the business logic consistency.

Deliverables:

1. Timeline view — functional audit
- Drag & drop of a reservation between tables: is the existing move endpoint actually wired to the UI?
- Overlap / double-booking detection
- Table combination (two 2-seaters merged into one 4-seater)
- Service rotation (two seatings on the same table in one evening)
- Walk-in creation from the view
- Tablet usability — this is the real-world use case, not desktop

2. 2D floor-plan view — feasibility assessment
- Do the table records currently store x/y coordinates? If not, what does the migration look like?
- What exists today vs. what needs to be built
- Realistic hour estimate for a production-ready editor

3. Written report (2-3 pages)
- What works, what is broken, what is missing
- Prioritised list: blocking / important / nice-to-have
- Your honest estimate for each

We want a real assessment, not reassurance. If the code is bad, say so.

If this goes well, we move to an ongoing engagement (20-25 h/week) through December.


WHAT WE ARE LOOKING FOR

Required
- 5+ years of professional full-stack JavaScript experience
- Solid SQL, comfortable with schema migrations on a live database
- Comfortable with SSH, environment variables and server-side debugging
- Experience with Stripe subscriptions
- Fluent written English
- European timezone (CET +/- 3 hours) — we want real-time overlap

Strong plus
- French (working language on our side, but English is fine)
- Experience taking over an undocumented codebase
- Multi-tenant SaaS experience

Not a fit
- Agencies subcontracting the work
- Teams operating behind a single freelancer profile
- "I can do everything" generalist proposals


HOW WE WORK

- NDA signed before any repository access
- You work on a dedicated branch; every change is reviewed before merge
- One 30-minute sync call per week, async the rest of the time
- All work is invoiced through Upwork
- Full IP assignment on all delivered work


COMMITMENT

Start date: immediately. The first assignment is ready to begin as soon as the NDA is signed — we are not waiting on internal approvals, budget cycles or anything else.

This is a deadline-driven engagement. We ship a first release in November and a second on 1 January 2027. If you cannot commit 20 h/week from now through December, please do not apply.

Rate is negotiable and based on experience. Please state your rate in your proposal.


TO APPLY

Please start your proposal with the word ORANGE, and in ONE sentence, tell us what you consider the riskiest part of the first assignment.

Proposals that do not follow this instruction will not be reviewed.

Do not send a generic portfolio. Tell us about one relevant project you built, and one thing that went wrong with it.

Include your hourly rate and how many hours per week you can start with this week.

I need an experienced developer to build and optimize a low-latency automation bot for my authorized workers.onech.at / OneChat account.

The main requirement is real-time WebSocket event monitoring and extremely fast response handling.

Requirements:

* Node.js or Go
* WebSocket / real-time gateway experience
* REST API experience
* Concurrent event processing
* Detect newly created ticket channels in real time
* Detect when the ticket form/process is ready
* Send the required claim command immediately after the correct trigger
* Support multiple tickets/channels simultaneously without events interfering with each other
* Prevent duplicate claims
* Reliable handling of message and message-update events
* Automatic recovery from WebSocket disconnects/errors
* Linux VPS deployment
* Detailed latency logging so we can measure event detection → command transmission time
* Clean, maintainable source code

Performance is very important. I do NOT want browser/Puppeteer automation if the functionality can be implemented directly through the WebSocket/API.

I already have the account/API credentials and the required platform information. The developer should work only with authorized accounts and documented/allowed interfaces.

Before hiring, please explain:

1. Your experience with WebSocket gateways and real-time systems.
2. Whether you would choose Node.js or Go and why.
3. How you would minimize latency.
4. Examples of similar real-time projects you have built.

Please do not apply if your experience is only with basic Discord/Telegram bots.

Project Overview:
I am looking for an experienced React Native and Expo developer to help me finalize and configure a mobile application project. I have already gathered all the necessary code, assets, and components, but I need professional assistance to properly connect all native modules and set up the Expo environment so the application can be successfully built and tested.

We will work in two main phases:
- Phase 1 (Initial Testing): Fix configurations, link native modules, and set up the Expo environment to generate a preview build for testing.
- Phase 2 (Final Production): Once everything is verified and works properly, we will proceed to generate the final production-ready builds.

Key Responsibilities & Deliverables:
- Review the existing project structure and configuration files (app.config.js, eas.json, etc.).
- Properly integrate and link native dependencies and plugins (such as Firebase, authentication, and mobile ads).
- Resolve any current build configuration issues or native version mismatches.
- Successfully set up the environment and run a preview build to test and verify the app (Phase 1).

What I’m Looking For:
- Proven experience with React Native, Expo, and EAS Builds.
- Strong understanding of native modules and configuration troubleshooting for both Android and iOS.
- Clear communication and efficiency in getting the app up and running.

If you have expertise in troubleshooting and setting up Expo production/preview builds, please share your relevant experience when applying.

I am looking for JavaScript/TypeScript developers with real experience building backend applications with Node.js and Express.js to independently test an open-source npm library:

ds-express-errors

Website & documentation: ds-express-errors.dev

The library provides centralized error handling for Express.js applications, including automatic error mapping for technologies such as Prisma, Mongoose, Sequelize, Zod, Joi, express-validator and JWT, custom HTTP errors, logging, configurable error responses, graceful shutdown utilities, and more.

Important: I am NOT looking for positive reviews

This is a paid developer testing session, not a request for promotion or a positive rating.

I want to understand how real Express.js developers experience the library.

If you dislike something, say so.

If an API feels badly designed, say so.

If the documentation is confusing, explain why.

If you find a bug, report it.

If you would not use the library in a real project, I want to know that too.

A negative review receives exactly the same payment as a positive review.

Your compensation is based on completing the developer test and providing thoughtful feedback, not on your rating or opinion of the library.

Who I am looking for

You should:

- Have real JavaScript and/or TypeScript development experience.
- Have practical experience with Node.js.
- Have practical experience building APIs with Express.js.
- Have previously worked with at least one relevant technology, such as:
- Prisma
- Mongoose
- Sequelize
- Zod
- Joi
- express-validator
- JWT
- Be able to independently create and run a small Express.js project.
- Be comfortable reading technical documentation.

I am specifically looking for developers with practical backend development experience.

I am not looking for AI/LLM developers, prompt engineers, no-code developers, or applicants without practical Node.js/Express.js experience.

Using AI as an ordinary development tool is fine, but the testing must actually be performed by you and the final review must represent your own experience and opinion.

The task

Create a small Express.js project and integrate ds-express-errors into it.

The application does not need to be large or production-ready. It exists only to give you enough real interaction with the library to evaluate its developer experience.

Start from the official website/documentation:

ds-express-errors.dev

I intentionally will not provide step-by-step integration instructions.

Finding, understanding and navigating the documentation is part of the test.

I want to see whether a developer encountering the library can understand how to use it from the existing documentation.

Use your real stack

Test functionality that makes sense based on technologies you already know.

For example:

- If you normally work with Prisma + Zod, you can test Prisma + Zod.
- If you normally use Mongoose, test it with Mongoose.
- If your Express applications use express-validator, that can be your test environment.

Do not choose a technology you have never used simply to test more features.

You do not need to test every feature of ds-express-errors.

A detailed test of functionality relevant to your actual experience is much more valuable than superficially testing every feature.

What to evaluate

While building the test application, pay attention to your natural experience with the library.

This can include:

- Installation
- Initial setup
- Getting started experience
- Documentation navigation
- Documentation clarity
- Code examples
- API design
- TypeScript developer experience
- Error presets / custom HTTP errors
- Automatic error mapping
- Configuration
- Error response customization
- Logging
- Integration with your database/validation libraries
- Error handling behavior
- Graceful shutdown
- Debugging experience
- Unexpected behavior
- Missing functionality
- Edge cases
- Anything else you naturally encounter

You do not need to artificially test everything on this list.

I am interested in what happens during realistic usage.

Deliverables

1. Test project source code

Submit the source code of the Express.js application you used to test the library.

It should contain enough code for me to understand how you integrated and used ds-express-errors.

Please remove all sensitive information before submission, including:

- ".env" files
- API keys
- passwords
- credentials
- tokens
- private/proprietary code
- personal information

Please include the relevant project files such as "package.json", source files, configuration, etc.

The project should demonstrate that the library was actually used.

2. Written developer review

After testing the library, write a review based on your actual experience.

The review should be published in the dedicated Reviews / Developer Experience category in the ds-express-errors GitHub Discussions.

"https://github.com/Dianka05/ds-express-errors/discussions/101" (https://github.com/Dianka05/ds-express-errors/discussions/101)

Please also submit the text of your review and the GitHub Discussion URL through Upwork as part of the final deliverables.

The review should be written naturally. You do not need to mechanically answer every question one by one.

However, it should contain enough detail to explain your experience.

Please include:

Library version tested

For example:

"ds-express-errors v1.x.x"

Your test stack

For example:

"Node.js + Express.js + TypeScript + Prisma + Zod"

Overall rating

Give the library an overall rating from:

1/10 — very poor

to

10/10 — excellent

Choose the score that genuinely represents your opinion.

There is no preferred or expected score.

Please briefly explain why you selected that rating.

Developer experience level

Please indicate whether you currently consider yourself a Junior, Mid-level, or Senior developer.

This is collected only to provide context for the review and to help me analyze feedback across different experience levels. It does not affect payment or how your feedback is evaluated

In your review, consider discussing:

- What did you build to test the library?
- Which features did you actually use?
- How easy was the initial integration?
- Could you understand how to use the library from the documentation alone?
- Was it easy to find the documentation you needed?
- Was anything unclear, incomplete, misleading or difficult to find?
- Were the examples sufficient?
- Which parts of the API felt intuitive?
- Which parts felt unnecessarily complicated or confusing?
- Did anything behave differently from what you expected?
- Did you encounter any bugs?
- Did you encounter edge cases that did not appear to be handled?
- Was debugging straightforward?
- Did the library remove boilerplate from your application?
- Was there anything you expected an Express.js error-handling library to provide but could not find?
- Is there functionality you think should be added?
- Is there functionality you think should be changed or removed?
- What did the library do particularly well?
- What did it do poorly?
- How would you improve the developer experience?
- How would you improve the documentation?
- Would you personally use ds-express-errors in one of your own projects?
- Would you consider using it in a production application?
- Why or why not?

Specific feedback is much more useful than general statements.

Instead of:

«The documentation could be better.»

please explain something like:

«I was trying to configure X. I expected to find it under Y, but the information was actually under Z. The example also didn't explain...»

The same applies to positive feedback.

Instead of:

«The Prisma integration is good.»

explain what made it good.

3. Paid testing disclosure

Because you are being compensated for the developer testing session, your GitHub review must clearly disclose this.

Please include a short statement such as:

«Disclosure: I received money compensation for independently testing ds-express-errors and providing my honest feedback. Payment was not dependent on whether my review was positive or negative.»

The disclosure should remain visible with the review.

Permission to use the review

By completing this contract and submitting your review, you give the ds-express-errors project owner permission to quote, reproduce and display your submitted review, in whole or in part, for project-related purposes.

This includes:

- ds-express-errors.dev
- Project documentation
- GitHub repository
- Project social media
- Articles about the project
- Other ds-express-errors promotional or informational materials

This permission also includes displaying screenshots of the public GitHub Discussion containing your review.

Your feedback will not be edited or quoted in a way that intentionally changes its meaning.

If only part of the review is quoted, it may be shortened for presentation while preserving the original meaning.

The material will remain identified as feedback originating from a compensated developer testing session.

GitHub identity

By completing the contract, you also permit the project to display the public GitHub username and public GitHub avatar associated with the review when showing or quoting your review.

No additional private personal information will be published.

GitHub Discussion availability

The GitHub Discussion is intended to remain publicly available after completion of the contract.

You may edit your review later to:

- correct mistakes,
- clarify your feedback,
- add additional observations,
- or provide updates after future versions of the library.

For example, if an issue you identified is fixed in a future version, you are welcome to update the review to mention that.

A copy of the original submitted feedback will also be retained as part of the Upwork contract deliverables.

Payment

$15 fixed price per completed developer test.

The payment covers:

1. Actually testing ds-express-errors in a small Express.js application.
2. Providing the source code of the test application.
3. Writing a detailed and honest developer review.
4. Publishing the review in the project's GitHub Discussions.
5. Submitting the review text and GitHub Discussion URL through Upwork.

Payment is not dependent on:

- giving the library a high rating,
- recommending the library,
- writing a positive review,
- avoiding criticism,
- or agreeing with the project owner.

A properly performed test resulting in a 2/10 review is just as valid as a 10/10 review.

When applying

Please answer the following questions:

1. Do you currently consider yourself a Junior, Mid-level, or Senior developer? (This will not affect candidate selection. I am collecting this information so I can compare feedback across different developer experience levels.)
2. How many years of professional or serious project experience do you have with JavaScript/TypeScript?
3. How much experience do you have with Node.js and Express.js?
4. Which of the following have you actually used in projects?

- Prisma
- Mongoose
- Sequelize
- Zod
- Joi
- express-validator
- JWT

5. Which stack would you most likely use to test ds-express-errors?
6. What types of Express.js applications have you worked on?
7. Please provide your GitHub profile and/or another example of your development work, if available.

Please do not send a generic AI-generated proposal.

I am selecting participants primarily based on actual Node.js/Express.js development experience, not on how polished the application message is. 

What I want from this project

The purpose of this project is to learn:

- What experienced developers understand immediately
- What confuses them
- Whether the documentation is sufficient
- Whether the API feels natural
- Which features provide real value
- Which features are unnecessary
- What is missing
- What should be improved
- What bugs or edge cases exist
- Whether developers would actually choose to use the library

I am looking for evidence and honest opinions, not praise.

I need a booking web application built from scratch for a small service based business. Looking for a developer who can
own the full stack, frontend, backend, database, and deployment, rather than just working off a rigid spec.
Tech stack requirements
Frontend: React.js (functional components, hooks), Tailwind CSS or Bootstrap for styling, fully responsive since a good
portion of traffic will be mobile.
Backend: Node.js with Express.js, RESTful API structure. JWT based authentication for the admin route, no need for OAuth
or third party auth providers at this stage.
Database: MongoDB, with Mongoose for schema modeling. Two core collections to start, one for services (name,
duration, price) and one for bookings (service reference, customer name, phone, date/time, status).
Deployment: Frontend on Vercel or Netlify, backend on Render or Railway, MongoDB Atlas for the database. Need a live
URL at handover, not just a local build.
Functional requirements
Public facing booking flow: customer selects a service, the app dynamically generates available time slots based on
service duration and configured business hours (no hardcoded slot list), and submits a booking with name and phone
number. No customer accounts or authentication required on this side.
Core requirement, non negotiable: slot conflict prevention. The API needs to reject a booking request if that time slot has
already been taken, including handling near simultaneous requests correctly, this isn't just a frontend disabled state, it
needs to be enforced server side against the database.
Admin dashboard: protected by JWT auth, single admin user is fine for now, no role based permissions needed.
Dashboard should list bookings grouped by date, with the ability to update a booking's status (upcoming, completed,
cancelled).
Out of scope for this budget
No payment gateway integration, no SMS or email notification service, no multi admin or staff level scheduling, no
recurring bookings. Keeping this phase 1 intentionally lean, these would be reasonable additions in a phase 2 if this goes
well.

Full-Stack React Native Developer

I’m looking for an experienced **Full-Stack React Native Developer** to make a small feature update to an existing production **social media-style mobile app**.

Main Features

The developer will update the complete **post management flow**, including:

* Improve the **post creation flow** and UI.
* Update the **post details screen**.
* Improve how users **view, add, edit, and manage comments**.
* Handle likes/comments and related post interactions where required.
* Integrate all changes with existing **REST APIs**.
* Update the **Node.js backend and database logic** when needed.
* Handle loading, success, and error states.
* Test the complete flow end-to-end without breaking existing features.

Tech Stack

* React Native
* Node.js
* REST APIs
* Existing Database
* Git/GitHub

Requirements

* Strong React Native experience.
* Good Node.js and REST API skills.
* Experience working with existing production apps.
* Ability to understand an existing codebase quickly.
* Good debugging and testing skills.

Timeline

This is a **small feature enhancement**, expected to take approximately **5–7 days**.

When Applying

Please share:

1. Your React Native experience.
2. Similar social media or feature-update projects.
3. Your Node.js/API experience.
4. Estimated timeline.
5. Fixed price or hourly rate.

Please apply only if you can independently handle both React Native and Node.js/backend changes.