Senior Full Stack Developer

Senior Full Stack Developer

Negosh · Engineering

• Full-time
• $150–170k
• 5+ years experience

About the product

• Brand licensing is a massive global industry that still runs on introductions and paperwork. At Negosh, we're rebuilding it around AI.
• Brands and manufacturers find each other on our marketplace, and an in-app assistant walks them through structuring and closing the deal.
• We work with some of the biggest brand owners in the world, helping them automate and improve their licensing programs.
• Very little software has ever reached this market, so almost everything we ship is the first version of itself.

The role
You'll own features end-to-end across a TypeScript codebase on both sides of the wire: a Fastify + Prisma backend and a Next.js + React frontend. A typical feature runs from a Prisma schema change and migration, through Zod-validated Fastify routes, to React Query hooks and MUI views, and ships with route-level integration tests that run against real Postgres and Redis in containers.

• Design and ship full-stack features across ~40 backend domain modules and a large component-driven frontend.
• Build and extend LLM-powered features: structured-output prompting, evidence gating, embeddings and vector search (pgvector), token budgeting, and cost tracking.
• Work on high-stakes negotiation flows: deal memo revisions, renewals, e-signature (DocuSign), and payments (Stripe, Plaid, Tipalti).
• Extend the multi-tenant white-label architecture: per-site theming, custom-domain SSO (OIDC), and site-scoped data.
• Maintain quality through heavy automated testing: Mocha + Testcontainers integration suites on the backend, Vitest + React Testing Library on the frontend.

Our stack

• Backend: TypeScript, Node.js, Fastify, Prisma, PostgreSQL + pgvector, Redis, Elasticsearch, Zod, OpenAI SDK, Cloudflare R2, Docker
• Frontend: Next.js, React 18, TypeScript, MUI + Emotion, TanStack Query, Zustand, react-hook-form, next-i18next, Stripe.js
• Testing & delivery: Mocha + Testcontainers, Vitest + RTL, GitHub Actions, TeamCity, Sentry, Sinon

Must have

• AI-augmented development (this one really matters to us): agentic coding tools (Claude Code, Cursor, Copilot, or similar) are a daily part of your workflow. You direct them well, review and validate what they produce, and know when not to trust them. We invest a lot in making our codebase legible to both humans and AI agents (convention docs, a linted project wiki, strong test guardrails), and you'll help us keep that going.
• 5+ years of professional full-stack experience, with deep TypeScript on both the server and the client.
• Production Node.js API experience: designing REST endpoints, request/response validation, auth (JWT/OIDC), background workers and queues.
• Production React experience: component architecture, server-state management (React Query or similar), forms, and responsive UI in a large codebase.
• Strong relational-database skills: schema design, migrations, and query performance in PostgreSQL (we run ~60 models and 400+ migrations).
• Testing discipline: you write integration and unit tests as part of shipping, not after.
• Ownership: you can take a loosely specified feature from a ticket to production, including the edge cases, the tests, and the docs. Since we're fully remote, this kind of self-direction is how we all work.

Nice to have

• Experience building LLM product features: structured outputs, embeddings/RAG, agentic pipelines, prompt evaluation, cost control.
• Fastify, Prisma, MUI, or Next.js specifically.
• Multi-tenant SaaS, payments infrastructure, or e-signature integrations.
• Internationalization, media processing pipelines (ffmpeg, sharp), or search (Elasticsearch, vector search).

How we work

• Small, senior, fully remote team: high trust, high autonomy, and no one looking over your shoulder.
• Every change ships behind CI gates (typecheck, lint, and full test suites on both repos).
• Backend integration tests run against disposable Postgres and Redis containers, so tests exercise real behavior rather than mocks.
• We document architecture decisions in a source-backed project wiki that both engineers and AI agents rely on, and we treat that documentation as part of the definition of done.