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Full-Stack Engineer (TypeScript) — AI Sales Training Platform Type: Contract 20-30 hrs/wk Location: Remote, with at least 9am–1pm US Central overlap You'd work with: me, the founder. I'm technical, so you won't be translating. What the product is A sales training web app for retail sales reps. Reps roleplay customer conversations with an AI customer, get scored, work through training modules, and practice product knowledge drills. Managers get a dashboard for their store. It runs in the browser and as an Android app on shared in-store tablets. It's live with beta users across several stores, which means the work you do gets used the same week you ship it. What you'd own You'd be the engineer on this product. I set direction, write the specs, and review. You build it, ship it, and help keep it healthy. New features for new clients. Every client gets its own content and its own vertical (golf, furniture, and fitness equipment so far), and sometimes features of their own. Most of it is full-stack: a Postgres migration, some API routes, React screens, prompt changes, tests. Bug fixes from real feedback. Reports come in through an in-app form and through me. You triage, write a failing test, fix it, ship it. Production support. Reading Railway logs, Sentry, and PostHog to work out why something broke. Everything goes to staging first, then a promotion PR to production. Data work. Schema changes are expand-only and backwards compatible. 49 migrations so far, and you'll write plenty more. The occasional call with a store manager who's stuck, and turning that into a fix or a help doc. It's a nice way to see who you're building for. Stack You'll touch all of this. You don't need prior experience with every piece. What matters is that you can open unfamiliar code and get somewhere with it in days. Language: TypeScript, strict mode, ~143k lines across backend and frontend Backend: Node + Express, modular route files, typed store interfaces Frontend: React 19 + Vite. No router library, no component library, no Tailwind. Plain CSS with design tokens, so there's less to learn than usual. Database: Postgres on Railway, plus pgvector for retrieval. SQLite locally. Raw SQL through pg, no ORM. AI: Anthropic SDK (Claude), OpenAI SDK, prompts kept in Nunjucks templates, Promptfoo for prompt evals including red-team suites Voice: Cartesia for speech-to-text and text-to-speech, plus a small Python service for speech emotion analysis Mobile: Capacitor 8 wrapping the same web app for Android Infra: Railway and GitHub Actions (11 workflows: unit, integration, Playwright E2E, hosted smoke tests, CodeQL, APK builds) Testing: node:test for backend, Vitest for frontend, Playwright for E2E. 250+ test files, so you'll usually know quickly when something's wrong. How we work I've put real effort into the development environment, and using it well is a genuine part of the job. You get Claude Code and Codex, both provisioned and paid for. Agents also run inside CI. Work is spec-driven. A feature starts as a written spec, then a plan, then a task list, then code. There are 28 specs in the repo you can read to see how it goes. Two-agent review: one agent writes, another reviews, and findings get addressed before anything merges. A handoff tool tracks who owns what, so nobody steps on anybody. There are project-specific skills for security review, migration safety, deployment debugging, and feedback triage. You'll use them, and I'd love it if you added more. The tooling does a lot of the typing. What I need from you is judgment: review what the agent writes the way you'd review a junior engineer's pull request, because that's roughly what it is. People who'd rather hand-write everything tend to be frustrated here. People who merge whatever came out green tend not to last. The job sits in between, and it's a good place to be. What we're looking for If you're close on most of this, please apply anyway. I'd rather read your application than have you screen yourself out. 4+ years building and shipping full-stack web apps Solid TypeScript. You know what strictNullChecks costs you and why it's worth paying. Real SQL. You can write a migration and work out why a query is slow without guessing. React. Hooks, state, and a sense for why a component re-rendered. You've shipped something that calls an LLM API in production, so tokens, cost, latency, streaming, and malformed JSON responses aren't new to you. You use an agentic coding tool daily (Claude Code, Codex, Cursor, Copilot Agent, Aider). Tell me which one and what you've built with it. You can debug from logs. Given a 500 and a log stream, you find the cause. Written English clear enough for a good PR description and a good bug report. Spoken English comfortable enough to get on a call with a non-technical retail manager in the US and actually help them. This is the one I can't be flexible on. Bonus points for any of: multi-tenant SaaS and row-level tenant scoping; real-time browser audio (getUserMedia, WebSockets, mic permissions, Chrome vs Safari); Capacitor or React Native; Railway, Render, or Fly; enough Python to keep a small FastAPI service running; Playwright. What you get Real ownership. You'd be the engineer on a live product, not a ticket in a queue. Direct access to the person making the decisions. No product committee, almost no meetings. A paid seat on the best AI coding tools, in a codebase built around them. If you want to get very good at agentic development, this is a good place to do it. Long-term work. I'm hiring someone to grow with the product, not to finish a project and leave. A few things to be upfront about It's an existing codebase, not a blank page. You're joining a working system with real users and established patterns. I'll ask you to work inside them first and propose changes once you know why they're there. It's a small team. Right now it's me. That means a lot of autonomy and no one else to hand a hard problem to. Production is real. Things occasionally break in front of live users, and we fix them that day. Not every day looks like that, but some do.
Project ID: 40655929
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Hi — Elias here from Miami. I see you're looking to develop an AI sales training platform with a full-stack focus. This project aims to create a robust system that can adapt and scale as user needs evolve. What usually matters most here is the integration of AI capabilities with a seamless user experience. A common issue in systems like this is ensuring data flows efficiently between components while maintaining security and permissions. The tricky part is usually managing workflow complexity, especially as features expand. My approach would involve structuring the application with clear modular components to enhance maintainability. I would prioritize stability, ensuring performance remains optimal as the user base grows. In similar projects where I've integrated AI with web and mobile platforms, I've found a solid architecture supports future enhancements without major overhauls. A few questions to better understand the scope: Q1 – What user roles do you envision for the platform, and how should their permissions be structured? Q2 – Are there specific integrations you require for third-party services or tools? Q3 – What are your expectations regarding scaling and user growth in the coming months? Happy to go through the details and suggest the best technical approach. Looking forward to hearing from you.
$50 USD in 30 days
8.9
8.9

A Warm Hello! We are readily available to start working on this project! We are a full-stack software development agency with strong experience building and maintaining TypeScript/React applications, Node.js backends, PostgreSQL systems, AI-powered products, real-time applications, and production SaaS platforms. We can provide an experienced engineer who can work closely with you as an extension of your team and take ownership of implementation, testing, deployment, and production support. We are ready to join the existing workflow, understand the codebase, earn ownership through reliable delivery, and help ship features that real users can benefit from the same week. Best Regards, Ana
$15 USD in 30 days
9.5
9.5

With over a decade of experience in full-stack architecture and high-scale systems, I understand your goal of developing an AI Sales Training Platform for retail sales reps. My background in building and scaling high-security systems for over 1 million users directly applies to the challenges of your project, ensuring its success in a complex environment. A strategic insight for ensuring scalability and security in this project is to prioritize strict TypeScript implementation and real SQL expertise. Drawing from my experience in developing high-complexity systems, including a Telegram Mini App serving over 1 million users, I am well-equipped to handle the intricacies of your AI platform development. I encourage you to reach out so we can discuss the roadmap for your project in more detail. I am confident that with my expertise in full-stack development, TypeScript, and real SQL, I can contribute effectively to the success of your AI Sales Training Platform.
$20 USD in 15 days
8.6
8.6

I have carefully reviewed your AI Sales Training Platform requirements and understand the existing production environment, full-stack ownership, and agent-assisted development workflow. I have 10+ years of experience with TypeScript, Node.js, React, PostgreSQL, APIs, AI integrations, testing, and production debugging. I am comfortable working in an existing codebase, understanding established patterns, writing safe migrations, building React features, integrating LLM APIs, debugging production issues, and maintaining strong automated test coverage. I also use AI coding tools such as Claude Code/Codex as development assistants while carefully reviewing generated code before merging. I WILL PROVIDE 2 YEARS FREE ONGOING SUPPORT AND COMPLETE SOURCE CODE. WE WILL WORK WITH AGILE METHODOLOGY AND PROVIDE ASSISTANCE FROM ZERO TO PUBLISHING ON STORES. I am comfortable with remote collaboration and can maintain the required US Central overlap. I am interested in a long-term engineering role and can start step by step. I eagerly await your positive response. Thanks
$20 USD in 40 days
8.5
8.5

I am a seasoned full-stack engineer with over 4 years of experience in building and shipping full-stack web applications, making me a strong fit for your AI Sales Training Platform. My expertise in TypeScript, particularly with strictNullChecks, and solid understanding of SQL performs well for complex query troubleshooting, aligns seamlessly with your project's stack and goals. Having worked extensively with TypeScript, Node.js, Express, and React, I have developed a keen aptitude for handling modular architecture and building intuitive UI components. My recent experience includes implementing and optimizing LLM API calls in production, which required managing token usage, latency, and handling malformed JSON safely. I frequently utilize AI-driven coding tools like Copilot, facilitating efficient development workflow. My comfort in debugging through logs ensures timely resolution of production issues. I am keen to learn more about how you foresee the expansion of this platform. Would you be open to a call to discuss potential contributions and alignment?
$20 USD in 40 days
8.4
8.4

Hello, I checked your "AI Platform Development - Full Stack" project description, it looks like the focus is on delivering a clean, responsive website that works well across all devices. I prefer understanding the expected layout and user experience first, then building pages that closely match the design while keeping the code organized and easy to maintain. Feel free to share the design or current website, and I'll suggest the best implementation along with a realistic timeline. Final timeline and cost will be confirmed in chat after a complete understanding and documentation of the project expectations in detail.
$15 USD in 1 day
7.8
7.8

Your brief stands out because the scope is very real: live product, beta users, production support, migrations, prompt work, and shipping features inside an existing TypeScript codebase. I work comfortably across backend/API work, React UI, SQL changes, debugging from logs, and LLM integrations, which fits this role well. I also like that your process is spec-driven and review-heavy, because that usually leads to cleaner releases and fewer regressions. I can overlap with US Central hours and would be happy to discuss the codebase and workflow further here on the platform.
$20 USD in 40 days
8.0
8.0

Hi, this is not automated bid and I know exactly what you need. I have experience for more than 10 years doing this work. My clients are mostly US based and you can easily check the review on my profile. I am comfortable with the US overlap time. Kindly contact me for further discussion.
$20 USD in 40 days
7.9
7.9

Hi there, I understand you need a full-stack engineer for your AI sales training platform using TypeScript, with OpenAI integration and mobile responsiveness. Working remotely with 9am-1pm US Central overlap fits my schedule perfectly. My approach involves building scalable full-stack applications with TypeScript on both frontend and backend, integrating OpenAI APIs for intelligent features, and ensuring mobile-first responsive design. I have extensive experience with Node.js, SQL databases, and modern frameworks including Vite for optimized builds. My Python background supports AI model integration and data processing requirements. I focus on clean, maintainable code with proper debugging practices and customer-centric solutions. Since you're technical, I can communicate directly about architecture decisions and implementation details without translation layers. The role's 20-30 hours per week commitment works well with my availability, and I'm ready to dive into development immediately. Best Regards, Khorshed Alam, RS Software
$30 USD in 40 days
7.3
7.3

With a track record of delivering full-stack solutions and complex AI systems, my team at MHTechFusion would be an ideal partner for your AI Sales Training Platform. We have extensive experience building applications that connect various hardware and software components into scalable, intelligent products - a skill set that aligns perfectly with your project requirements. In terms of technology stack, we're well-versed in TypeScript, Node.js, and React, just to name a few key tools. With over 143k lines of code across both backend and frontend, your project's substantial codebase holds no hesitation for us - we specialize in picking up unfamiliar codebases swiftly and making meaningful contributions within days. Furthermore, our expertise extends not only to the technical execution but also creating sophisticated integration between different components like the trainings modules. This involves developing secure API routes, databases migrations (using Postgres), and React-based UIs. We can assure you a thorough approach in maintaining migration safety and deployment standards to minimize any disruptions to the app's existing features.
$30 USD in 40 days
7.3
7.3

Hi there, I understand your system operationally: a sales rep initiates a roleplay on a web or tablet app. Their voice is transcribed, sent to an LLM (Claude/OpenAI) to formulate a response as an AI customer, and delivered back via TTS. The session is then scored, with analytics feeding a manager's dashboard. Technical approach: I will build upon your existing Node/Express backend and React 19 frontend, respecting the raw SQL and plain CSS patterns. I'll write backwards-compatible Postgres migrations, adjust Nunjucks prompts for new verticals, and ensure features perform within the Capacitor Android wrapper. Core modules: The AI Conversation Engine (handling the STT/LLM/TTS loop), Performance Analytics (scoring and reporting), Multi-Tenant Content System (for different clients), and the Training Module delivery interface. Relevant systems: We built an AI-Driven Sales Call Automation System which uses a similar conversational loop: automated voice interaction, transcript analysis, and outcome classification. My implementation strategy aligns with your agentic workflow. I use Claude Code daily and will focus on applying judgment to review AI-generated code, ensuring architectural soundness, and writing robust tests before merging anything. Regards, Rohit
$15 USD in 120 days
7.5
7.5

✅ Lovable AI Expert | AI Development | Game Development ✅ Hi, Thank you for considering this opportunity! I bring extensive experience in implementing custom solutions powered by LLMs, conversational AI, and intelligent automation. Recently I have been working on Lovable AI for developing a gaming platform using it, complete with chat-based agent logic, expressive front-ends, and backend integrations. See here : In other project, implemented a fully automated AI agent system for intelligent meeting creation using ElevenLabs Conversational AI and Gemini (via a custom agent brain). The flow integrates voice interaction, natural language processing, location precision, and frontend. Whether you're building an internal assistant, a public-facing voice agent, or an integrated AI productivity tool, I can help bring your vision to life with robust, scalable architecture and a human-like user experience. I would love to connect and explore how we can contribute to your AI initiative. Regards Ranjana
$20 USD in 40 days
7.3
7.3

This looks like a strong fit for my background in full-stack product work, especially where TypeScript, React, Node, Postgres, and ongoing feature delivery all come together. I’m comfortable joining established systems, following existing patterns first, and handling the mix of feature work, bug fixing, and production troubleshooting you described. The fact that the app is already live and used weekly makes the work more meaningful, and I’d be glad to contribute with that ownership mindset. I can support your required time overlap and can start shortly.
$15 USD in 40 days
7.0
7.0

Hello!, This is James from Hollywood... I read your AI Sales Training Platform post carefully, and what stands out is that you need a Full-Stack Engineer who can build a real production-ready TypeScript platform, not just connect a few APIs. I’ve spent 15+ years building full-stack systems with Node.js, Python, TypeScript, OpenAI, SQL, and modern frontend stacks like Vite, so this is a strong fit. My approach would be simple and practical: 1) confirm the training flow, roles, and success metrics 2) build the AI interaction layer and data model 3) connect the frontend, backend, and admin tools 4) test, debug, and refine the UX for real users I’ve built AI automation tools, SaaS dashboards, customer support workflows, and data-heavy platforms where reliability mattered as much as speed. I pay close attention to the small details that often decide whether a product truly works well. Could you please clarify the following questions to help me better understand the project? 1) What should the AI training flow include: roleplay, coaching, scoring, or all three? 2) Do you already have the UI/UX, or should I help shape the Vite frontend structure? 3) Will user accounts, progress tracking, and admin controls be needed from the start? If helpful, I can share a few relevant builds in AI tools, internal dashboards, and web apps I’ve shipped recently. I’d be glad to jump into chat and map this out properly.
$50 USD in 30 days
6.9
6.9

I understand the need for a robust AI sales training platform that provides immediate utility to retail sales reps and managers. Our team is equipped to enhance your existing application, ensuring it runs smoothly and effectively addresses user needs. With your focus on TypeScript and React, we’ll streamline your full-stack development, implementing the required Postgres migrations and API routes efficiently. Our approach prioritizes thorough testing and bug fixes based on real feedback, enhancing the user experience continuously. We have extensive experience with TypeScript, Node, React, and PostgreSQL. Also, communication, quality, and on-time delivery are priorities. If you'd like, I can also share similar work we've completed and discuss the best approach for your project. Regards, JP
$15 USD in 7 days
6.8
6.8

Hi, The sales training platform with AI role-playing sounds like a practical full-stack build where real-time feedback and content management are key. The mix of Postgres migrations, React screens, and LLM prompt changes aligns with what I’ve done in similar systems where features need to be scoped quickly and tested thoroughly before shipping. I’ve worked on systems where AI-driven workflows required strict rate limit handling and careful token budgeting, and this one looks like it’ll need the same attention to avoid unexpected costs. The Android side via Capacitor also means keeping an eye on how the web features translate to mobile constraints. I can start working right away. Let's connect and discuss the details. Thanks, Denis.
$15 USD in 40 days
6.5
6.5

Hello, With over a decade of experience, particularly in full stack, SQL and web development, WellSpring Infotech is well-equipped to build the AI sales training platform that you envision. We understand your need for a strict, efficient and scalable language like TypeScript, as well as a smooth functioning database like Postgres on Railway; areas we shine through in. Our comprehensive portfolio in backend and frontend technologies includes proficiency in Node Express and React, which you consider essential for this project. We also bring versatility to the table with an ability to adapt to unfamiliar codebases within days - a trait that has helped us thrive in similar high-pressure environments beforehand. Moreover, we understand the significance of maintaining continuous communication and delivering on schedule. While you take charge of setting direction and writing specs, we're here to handle the technical side. Given that we specialize in various Content Management Systems including WordPress and Wix, we can tune these traits dependence on specific client needs which your app demands. With us onboard, rest assured of exceptional work quality as well as post-project support invariably. Choose WellSpring Infotech today to create an eCommerce experience optimized for growth and success. Thank you
$15 USD in 40 days
6.7
6.7

Full-Stack TypeScript Engineer I can work directly on your existing TypeScript codebase, handling full-stack features, production bugs, SQL migrations, AI integrations, testing, and deployment. Here's my approach: → Build React/TypeScript features and Node/Express API routes → Write safe PostgreSQL migrations and optimize SQL queries → Work with Claude/OpenAI APIs, prompts, streaming, cost, and error handling → Debug production issues through logs and monitoring, then add regression tests → Use agentic coding tools with proper review instead of blindly merging generated code Flow Spec → Plan → Development → Tests → Agent Review → Staging → Production Question Which part of the current product needs the most attention first—new client features, production bugs, AI/voice workflows, or database work? Let's connect... Thanks
$18 USD in 40 days
7.2
7.2

As an expert in full-stack development, with a solid knowledge of Node.js and Python, I'm confident in my ability to contribute in an impactful way to your AI Sales Training Platform. Having worked on a diverse range of projects, I understand the importance of being adaptable and resourceful when it comes to unfamiliar code - I don't shy away from challenges but rise up to meet them head-on. With over 10 years of experience as a software developer and a track record of delivering robust, functional solutions for complex business needs, I know that I possess the skills to be successful in this role. I want to emphasize that while I may not have direct experience with all aspects of your tech stack, my expertise lies in quickly grasping new languages and tools and fluently incorporating them into ongoing projects. This has been evident in my work where I exceeded client expectations by finding innovative solutions to unique problems. Additionally, my frontend proficiency extends beyond React screens and also includes TypeScript which synchronizes perfectly with the skill-set requirements for your platform. At Web Crest, we believe in building long-term relationships with clients like yourself, where we can contribute our skills and expertise not just for immediate benefits but provide long-term technical support as well.
$20 USD in 40 days
6.6
6.6

Hi, I'm interested in your project "AI Platform Development - Full Stack". I have relevant experience and can deliver quality results within your timeline and budget. I'd love to discuss the details. Please feel free to reach out.
$20 USD in 40 days
6.2
6.2

Tulsa, United States
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