
Senior Full Stack Engineer
- On-site, Hybrid
- Amsterdam, Noord-Holland, Netherlands
- Product Engineering
Build features end to end, from the data model to the production UI, on a platform that collects 100M+ data points a day from a variety of LLMs.
Job description
Build features end to end, from the data model to the production UI, on a platform that collects 100M+ data points a day from ChatGPT, Claude, Perplexity, Gemini, Google AI Overviews and the other major AI engines. Does this sound like you?
As our Senior Full-Stack Developer, you'll own features from start to finish: scope them with product and design, build the schema and the API, ship the UI, and keep an eye on them in production. The team is small, you get real autonomy, and code ships the same day. You'll work directly with the founders, with no management layers between you and the decisions.
About us & our engineering stack
Promptwatch is building the leading platform for Generative Engine Optimization (GEO), helping brands understand, measure, and improve how they appear across AI search platforms like ChatGPT, Gemini, Claude, Perplexity, and AI Overviews. Brands like Duolingo, Yelp, Typeform, Fireflies, and Shutterstock, along with agencies worldwide, rely on Promptwatch to turn AI Search into a measurable growth channel.
Making that possible takes serious engineering. We collect AI answers from the live interfaces of each engine, routed through geo-located proxies so a monitor sees exactly what a user in a given country, state, or city would see. We stream AI crawler logs in real time from CDNs like Cloudflare, Fastly, Akamai, and CloudFront. And we index every customer's site into Elasticsearch with paragraph-level embeddings, so we can re-run the same query fan-out AI engines use and test whether their content can answer it.
The stack is a TypeScript monorepo (React, Next.js, Fastify, Prisma, tRPC) on Postgres, Elasticsearch, Redis, and ClickHouse, running on Google Cloud. It's split into several services, including the API server, an AI gateway, ingest pipelines, and log processing, and each one has its own scaling problems.
Responsibilities
Take features from problem definition to production: scope with product and design, build the schema, write the API, ship the UI, and monitor it once it's live
Design and improve the data pipelines that move millions of records a day through Postgres, Elasticsearch, Redis, and ClickHouse
Build and run services on Google Cloud (Cloud Run, Pub/Sub, CI/CD) and keep them observable with Sentry, structured logging, and custom dashboards
Help shape how we work: code review standards, testing (Vitest, Playwright), and technical direction
Work directly with the founding team on what to build and how
Job requirements
5+ years of experience building production web applications, with ownership of features across frontend and backend
Strong experience with TypeScript, React, and Node.js (we use Fastify, but experience with other frameworks carries over)
Comfortable designing and querying relational databases (we use Postgres with Prisma)
Experience building APIs, whether tRPC, REST, GraphQL, or a mix
Familiarity with job queues, async processing, or event-driven architectures
You write tests and take code review seriously
Comfortable working in English with Product, Design, and the founders
Nice to have
Elasticsearch, ClickHouse, or other analytical datastores
Embeddings, semantic search, or retrieval (RAG) systems
Working with LLM APIs (OpenAI, Anthropic, Google)
Large-scale scraping, log processing, or high-volume ingest pipelines
Data visualization (Recharts, D3, or similar)
Monorepo tooling (Turborepo, pnpm workspaces)
Google Cloud Platform
Experience at an early-stage, fast-growing startup
Benefits
Competitive salary
HQ at Leidseplein, in the heart of Amsterdam
Team off-sites and company events
Sports activities, including our own run club
Growth opportunities as our engineering team grows
A real say in product and technical direction
A well-maintained codebase: strict TypeScript, Oxlint linting, thorough types
Time and budget for learning: conferences, courses, books
If you're excited about owning features end to end and building a platform that grows with Promptwatch, we'd love to hear from you.
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