Senior Full-Stack Developer

at Promptwatch

📍 Amsterdam, Netherlands

EUR 80,000-110,000 per year

SENIOR

✅ Hybrid

Used Tools & Technologies

PostgreSQL

Required Skills & Competences
Tag name is followed by "@" symbol and proficiency level value. About proficiency levels:

1-2 — basic awareness. Minimal hands-on experience, and a rudimentary understanding of the technology's purpose;

3-6 — daily use. Comfortable and regular usage, capable of handling common tasks and challenges related to the technology;

7-9 — you are an expert, you can teach others, you know all the pitfalls and tricks;

10 — exceptional knowledge, comprehensive understanding, and adeptness in all aspects of the technology, including advanced problem-solving. Think twice before claiming or demanding such level.

ElasticSearch @ 4 Redis @ 4 Playwright @ 4 TypeScript @ 7 CI/CD @ 4 Next.js @ 4 React @ 7 Node.js @ 7 Microservices @ 4 API @ 4 LLM @ 4 GraphQL @ 4 Sentry @ 4 ChatGPT @ 4 Observability @ 4 AI @ 4 Data Visualization @ 4 ClickHouse @ 4 Data Pipelines @ 4

Details

Own features end-to-end — from data model to production UI — at a platform that processes 1.1B+ data points across ChatGPT, Claude, Perplexity, and every major AI engine. Small team, real autonomy, code ships the same day. If you care about building things that work at scale and want to see your work matter immediately, this is the role.

Promptwatch helps businesses understand how they appear in AI-generated answers. We track citations, sentiment, and visibility across every major AI engine, processing billions of crawler logs and AI responses in real time. Thousands of companies use what we build to make decisions every day.

Responsibilities

Take a feature from problem definition to production: scope it with product and design, build the schema, write the API, ship the UI, and monitor it in prod
Design and improve data pipelines that move millions of records through Postgres, Elasticsearch, Redis, and ClickHouse daily
Build and operate microservices on Google Cloud (Cloud Run, Pub/Sub, CI/CD) — including keeping them observable with Sentry, structured logging, and custom dashboards
Contribute to how we work: code review standards, testing practices (Vitest, Playwright), and technical direction
Pair with the founding team directly — no layers of management between you and decisions

Requirements

Strong experience with TypeScript, React, and Node.js (we use Fastify, but framework-specific knowledge transfers)
Comfort 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
A habit of writing tests and reviewing code thoughtfully