We are looking for an exceptional Full-Stack Engineer who enjoys solving challenging technical problems across the entire technology stack—from modern user interfaces to scalable backend services, cloud infrastructure, and AI-assisted software development. This engagement begins as a contract position with strong potential to become a long-term member of our engineering team. What You’ll Be Building This is not a typical CRUD application. You will be working on a technically sophisticated SaaS platform involving: • AI-powered healthcare analytics • Large-scale clinical and pharmacy datasets • Complex SQL and data processing pipelines • Interactive analytics dashboards • Modern React-based user interfaces • High-performance backend APIs • Enterprise system integrations • Cloud-native infrastructure • AI-assisted software engineering workflows If you enjoy designing scalable systems, solving complex technical challenges, and building products that have real-world impact, we’d love to hear from you. Responsibilities You will work closely with our founders and engineering team to: • Design and develop new product features from frontend through backend. • Build intuitive, responsive, and high-performance web applications. • Design scalable backend services and REST/GraphQL APIs. • Design and optimize relational databases and complex SQL queries. • Improve application performance, scalability, and reliability. • Build integrations with external healthcare systems and third-party services. • Participate in architectural and technology decisions. • Debug and resolve complex production issues. • Write clean, maintainable, well-tested production code. • Contribute to engineering best practices and continuous improvement. Required Technical Skills Frontend • React • TypeScript • Modern JavaScript • Responsive web development • Component-based architecture • State management Backend • Expert-level Python • Node.js • FastAPI, Django, or Flask • REST APIs • GraphQL • Authentication & Authorization • Asynchronous programming Databases Strong experience with relational databases including: • PostgreSQL • MySQL • SQL query optimization • Indexing • Performance tuning • Data modeling • Database design Cloud & Infrastructure • Docker • Kubernetes • AWS • CI/CD pipelines • Git Modern AI-Assisted Development We strongly prefer engineers who actively leverage modern AI-assisted software development tools to improve productivity while maintaining exceptional engineering quality. We view AI as a productivity multiplier—not a replacement for software engineering expertise. The ideal candidate understands how to use AI effectively while applying sound engineering judgment, architecture, debugging skills, and rigorous code review. What We’re Looking For We’re looking for engineers who: • Think like software architects—not just programmers. • Can independently solve complex technical problems. • Take ownership of their work. • Write elegant, maintainable, and well-tested code. • Have excellent debugging and troubleshooting skills. • Make thoughtful architectural decisions. • Learn quickly and continuously improve. • Communicate clearly and professionally. • Enjoy working in a fast-moving startup environment. We value engineering excellence, problem-solving ability, and sound technical judgment far more than years of experience alone. Nice to Have Experience with one or more of the following is a plus: • Large-scale analytics platforms • Event-driven architectures • Redis • Elasticsearch • Message queues • Data engineering • Performance optimization • DevOps Required Application Questions To help us identify the strongest candidates, please answer the following questions in your proposal. 1. Describe the most technically challenging application you have built. Please include: • Overall system architecture • Your specific role • Technologies used • The biggest technical challenge • How you solved it • What you would do differently today 2. Which area of software engineering do you enjoy the most, and why? Examples: • System architecture • Backend development • Frontend development • Databases • Performance optimization • Infrastructure • Debugging • AI applications

I am seeking a skilled React Native/Expo developer to complete an existing sports notification app. The project involves working with existing code to enhance features and ensure smooth functionality. The ideal candidate should have experience in mobile app development and be able to deliver high-quality results efficiently.

We are a fast-growing telecom / AI-First CPaaS serving sms and voice API's. We are building the first AI-first communications platform (SMS, Voice, RCS, AI agents) designed for speed, simplicity, and real-world business outcomes. We are not looking for a “task completer.” We are looking for a true senior engineer who: thinks in systems moves fast makes decisions independently writes clean, scalable code uses AI tools (Claude, etc.) as a force multiplier ⚠️ Read This First *DO NOT APPLY IF YOU ARE PRETENDING TO BE IN A DIFFERENT COUNTRY. PROOF OF RESIDENCY IS REQUIRED. Most applicants will not be a fit. If you need: detailed tickets hand-holding constant direction This is NOT the role for you. If you are the type of engineer who: sees a problem and solves it end-to-end improves architecture without being asked ships quickly without sacrificing quality You will thrive here. What You’ll Do Build and ship full-stack features across our platform (messaging, voice, AI workflows) Make architectural decisions (not just implement) Improve system performance, reliability, and scalability Work directly with founders (no PM layers) Move from idea → production very quickly What We Expect (Non-Negotiable) 5+ years real full-stack experience (not just titles) Strong backend experience (Node.js / APIs / infra) Strong frontend experience (React or similar) Experience building production systems at scale Ability to work autonomously with minimal direction High ownership mentality Bonus (but highly valuable) Experience with telecom / CPaaS / messaging Experience with AI integrations (LLMs, agents, workflows) Experience optimizing performance at scale Startup experience (especially early-stage or fast growth) How We Work Small, high-output team Very fast iteration cycles No unnecessary meetings High trust, high expectations We use AI tools heavily (Claude, etc.) — you should too What We Care About Most Not your resume. We care about: How you think How you build How fast you execute The quality of your code To Apply Please include: Links to projects you’ve built (real production work) A short explanation of: a system you designed end-to-end a difficult technical decision you made independently Your GitHub Optional (but strong signal): Share how you use AI (Claude, etc.) in your workflow Compensation Competitive (based on experience) Long-term opportunity with a fast-growing, profitable company If you are truly senior, this will feel obvious. If not, this role will be very uncomfortable. **THIS IS A FT, HOURLY ROLE. PROVIDE YOUR REQUESTED HOURLY RATE IN PROPOSAL**

We launched a social TV tracking app on iOS where people log what they watch, follow friends, post, browse a home feed, customize profiles, open show pages, set watch status (currently watching, completed, etc.), and see what’s airing next. We’re live with about 1,800 users. The product works and looks nice, but the app is still too slow - screens take too long to load, and it doesn’t feel ready to grow. Stack Expo (SDK 54) / React Native, TypeScript, Expo Router, Supabase (Postgres, Auth, Storage, Edge Functions), EAS builds and OTA updates. Show metadata comes from TMDB and Trakt. The job We need a senior engineer to review the current system (app + database + background work) and make it fast and scalable. We’ve already done a lot of caching, SQL/RPC work, and client loading improvements. It’s better in places, but overall it’s still not where it needs to be. We’re looking for someone who can diagnose where time is actually going and ship the changes that matter — database, backend, and client — then leave things in a state we can keep fast as we add users. I want a solution to be able to hypothetically scale to 1M users tomorrow, if we wanted. Not just something that will break again at 10k users. Who this is for Strong Postgres and Supabase experience, plus real React Native production work. You’ve scaled a consumer app faster before, not just built features. To apply Send a short note on similar work you’ve shipped, your rate and weekly availability, and how you’d approach the first week. Repo and environment access after we talk.

Vienna Consulting is a consulting firm that has built a modern, referral-based home-services platform that connects homeowners with vetted, licensed service providers. The platform is already live. I'm looking for a solo developer to build two well-defined features on the existing codebase. The stack is React on the front end, Python on the back end, MongoDB on Atlas for the database, hosted on Render, with Google OAuth for login. The two areas you'd build sit behind a login, so they aren't publicly viewable,I'll walk you through the existing system before you start. Then, what I need built. One, the Admin Dashboard, build this first,a simple control panel to create and manage users by hand, clean directories of your customers, agencies, and technicians, and a detailed booking view. Two, the Commission Ledger,marking a job Completed logs a flat one hundred dollars, each technician sees Lifetime Earnings, Paid to Date, and Current Balance Owed, paid records are kept never deleted, and the app only tracks money, never moves it. Keep it lean and simple. Who you're looking for: a solo developer comfortable in an existing codebase, strong fluent English, closest to Eastern Time preferred. Hiring process: a live video call is required before hiring, non-negotiable, and you'll start with one small trial task first.

Job Description Project Overview We have a fully code-complete Micro-SaaS platform called BounceBack SMS. The app is an automated missed-call text-back and lead recovery system built using Next.js 15, Tailwind CSS, Twilio API, and Supabase. The repository is isolated, structured, and securely hosted in a private GitHub repository. We are looking for an experienced Full-Stack/DevOps Engineer to handle the production deployment, configure live API pipelines, manage database environment mapping, and ensure the entire setup runs on a frictionless, automated continuous integration/continuous deployment (CI/CD) framework. Scope of Work (Key Deliverables) 1. Infrastructure Mapping & Production Deployment Deploy the Next.js 15 frontend/backend application from our private GitHub repository to production hosting (Vercel/Render). Map and connect production environment variables, database schemas, and connection strings to our live database instance (Supabase/PostgreSQL). Configure a permanent automated CI/CD pipeline (e.g., GitHub Actions or Vercel integration) ensuring any future push to the ⁠main⁠ branch automatically rebuilds and deploys the app flawlessly. 2. Twilio API & A2P 10DLC Compliance Configuration Connect and secure our live Twilio API gateways within the backend architecture. Audit and verify that our messaging endpoints cleanly support incoming webhooks for missed-call detection. Crucial Milestone: Assist and audit our US A2P 10DLC Campaign Registration via Twilio to ensure 100% carrier delivery compliance (Privacy Policy and Terms pages are already live and coded in the repo). 3. Live Stripe Billing Integration Transition our checkout environment variables from Stripe Sandbox/Test Mode into Live Production Mode. Wire up our exact pricing architecture: $0 Setup Fee, 100 Free Leads Usage Trial, transitioning into a flat $19.99/Month Recurring Subscription. Ensure Stripe webhooks are completely listening to successfully provision, pause, or update customer account access tiers inside our database based on subscription state. 4. Handover & Bulletproof Documentation Provide a brief, plaintext ⁠.txt⁠ or ⁠.md⁠ technical handover file outlining the deployed environment structure, a list of active API webhooks, and step-by-step instructions for simple environment variable updates. Required Tech Stack Expertise Frameworks: Next.js 15 (App Router), React, Tailwind CSS Database: Supabase / PostgreSQL (Schema sync, migrations, security policies) APIs: Twilio SMS Gateway (Webhook architecture, A2P 10DLC registration compliance) Payment Rail: Stripe Billing API (Usage-based trials, recurring webhooks) DevOps/Version Control: Git, Private GitHub Repositories, Vercel/Render, CI/CD automation Preferred Qualifications Proven track record deploying independent Micro-SaaS or automation applications. Deep familiarity with strict US telecom carrier A2P SMS delivery guidelines to prevent messaging blocking or spam flags. Obsession with clean environment variable separation—absolutely no hardcoded credentials. Excellent technical communication skills and availability to run live end-to-end integration testing before final milestone sign-off. 🎯 Candidate Screening Questions (Include on Upwork) 1. Briefly describe your experience configuring Twilio webhooks and handling the US A2P 10DLC registration process to ensure high carrier delivery rates. 2. How would you configure Stripe to trigger a recurring $19.99/mo flat-rate subscription specifically after a user consumes exactly 100 free database actions/leads? 3. Confirm that you are comfortable working out of a private GitHub repository and setting up an automated CI/CD pipeline so I never have to manually pay for developer redeployments.

We are looking for an experienced React Native developer to build Airway Formula — a mobile wellness app for patients undergoing palate expansion treatment (MARPE, FME, MSE). The app includes a daily exercise program with embedded video, an expansion turn tracker with push notifications, symptom self-check with trend graphs, streak and compliance tracking, a personal photo log, a static education library, and a treatment timeline. Full project brief is attached. This is a fixed-price, milestone-based engagement with a budget of $1–$4,000. You must have at least one React Native app live in the App Store, prior Firebase and RevenueCat experience, and have strong UI/UX design capability. We will provide general layout direction and wireframes in Figma, but we are looking for a developer who can take that foundation and deliver a polished, professional aesthetic with proper app flow — think Apple Health meets Headspace. Full source code ownership transfers to the client at project completion. If this sounds like a fit, please read the attached brief carefully before submitting your proposal — we will only respond to proposals that address the specific questions outlined in Section 08.

I have created a web version of a card-sorting college matching app for high school students. I need it rebuilt as a native iOS React Native app. This is a well-scoped job with a working product, an existing backend, and clear deliverables. You are not figuring out what to build, you are converting something that already works into a IOS App. TECH STACK • React Native (bare or Expo — justify your choice) • Gesture-based card UI using industry-standard React Native animation libraries • Calls an existing backend API that returns AI-generated college matches • Source code available on GitHub upon signing NDA • Target: iOS 16+ | Must be built with latest Xcode and iOS SDK TO APPLY YOU MUST INCLUDE: 1. One live App Store links to React Native apps you have shipped 2. Confirmation you are running Xcode 26 3. Two sentences on how you would implement the drag-to-zone card gesture. Applications missing any of the three will not be reviewed. Looking for one developer who has shipped gesture-heavy iOS apps and knows App Store submission from experience.

I’m looking for an experienced full-stack developer to help improve an existing React Native mobile app and build a modern web platform for the same product. The mobile app is already live on the App Store, and I’m looking to modernize the UI/UX, improve the overall user experience, and add new features over time. Alongside the app, I need a responsive website where users can learn about the platform, create accounts, subscribe, and manage their information through a secure dashboard. The platform is focused on amateur basketball leagues and will continue to grow, so I’m looking for someone who can build with scalability and maintainability in mind rather than simply delivering a one-time project. I’m looking for a developer who: * Has strong experience with React Native and modern web development * Is comfortable working with Firebase and subscription-based applications * Writes clean, scalable, well-documented code * Uses modern AI development tools (such as Cursor, Claude, GitHub Copilot, etc.) to work efficiently * Can communicate clearly and contribute to technical decisions This has the potential to become a long-term working relationship as the platform continues to expand. My goal is to find someone who can initially build the next phase of the product and potentially continue as the technical lead as we grow.

Project Scope Amoidi is an AI-driven curriculum adaptation engine for K–12 educators that automatically transforms educational content into tiered, pedagogy-backed worksheets, bilingual scaffolding (ELL support), and specialized STEM exercise layouts. We have completed initial feature development and 5 comprehensive system audits. All core features and pipeline code are fully written. We are seeking an expert engineer for a 6-hour initial sprint to audit pipeline traces, fix high-priority integration bugs, and establish a firm timeline for commercial launch readiness. Tech Stack & Tooling Note Platform Stack: Built on the Lovable stack (React 18 / Vite / TypeScript frontend + 140+ Supabase Deno Edge Functions). Agentic Developer Workflow: Maintained and audited using modern AI CLI tools (specifically Claude Code CLI). Candidates should be comfortable navigating codebases supported by AI coding assistants. Repository Documentation: Supported by comprehensive docs (CLAUDE.md, ARCHITECTURE.md, and CHANGELOG.md) outlining edge-function maps, duplicate-file byte-parity rules, and system conventions. In-Platform Diagnostic Panel: Includes a live in-platform Diagnostic Admin Panel to trace pipeline execution, review shadow comparator outputs, and pinpoint error states instantly without guessing. Test Suites: Backed by 144+ passing visual/layout golden tests and Vitest unit suites. The 6-Hour Sprint Structure - Milestone 1 This engagement begins with a focused, capped 6-hour milestone designed to deliver immediate results while protecting project budget: Budget & Bidding Note: * This job is posted as a Fixed-Price Milestone 1 (Capped at 6 Hours). Please submit your bid for the 6-Hour Sprint (target range: $400 – $600 based on your experience and rate). Your bid should cover the ~1.5-hour diagnostic audit + ~4.5 hours of active bug fixes on our Master Checklist. Audit & Trace (~1.5 Hours): Use our live Diagnostic Admin Panel, architecture docs, and test suites to trace pipeline execution across our 5 core tools. Active Bug Fixes (~4.5 Hours): Execute and test high-priority fixes from our checklist (e.g., L1 purge gate alignment across parallel implementations, classifier tie-breaking, contextual image binding, or PDF chip rendering). Sprint Wrap-Up: Deliver committed, verified code for completed fixes, along with a firm time/cost quote for any remaining items. Note on Hire: Upon hire and kickoff, you will be handed our complete "Scope of Work" checklist outlining all backlog items across our 5 core tools so you can triage and execute immediately. Successful completion of this initial sprint will immediately unlock Milestone 2 to wrap up the remaining backlog for our commercial launch. Required Qualifications Deep expertise in TypeScript, Deno, and Supabase Edge Functions. Hands-on experience working within the Lovable platform architecture and LLM API Gateways. Proficiency using Claude Code CLI or similar agentic AI tools for fast repository tracing and refactoring. Strong discipline around unit testing, regression testing, and maintaining strict byte-parity across duplicate/shared edge modules.