Senior Full Stack Engineer (m/w/d)

Start: as soon as possible Location: Berlin Mitte or Potsdam-Babelsberg We have two offices, one in Berlin Mitte and one in Potsdam-Babelsberg. You can work from either location. PLACED is a Berlin-based AI startup rebuilding how Europe's 30,000+ recruitment agencies win business. We combine large-scale job market data with agentic AI, turning outdated, manual workflows into intelligent, automated pipelines. We have just closed our first institutional funding round. We're looking for Senior Full Stack Engineers to help us take the product to the next level. You'll work on real features for real users with impact from day one. We're seeking exceptional, A-player engineers who own the full slice: from pixel-perfect Next.js interfaces to high-performance FastAPI and Hono backends, LLM pipelines, and cloud infrastructure. You'll design data models with PostgreSQL, ship production AI features, and help drive our backend migration from Python to TypeScript. Our tech stack Backend: Python 3.13, FastAPI (primary production API, 123+ endpoints); TypeScript 5, Hono, Bun (new backend in active development) Frontend: TypeScript, React, Next.js 16 Database: PostgreSQL 17 (pgvector for vector search), Redis (caching, async flags) Infrastructure: AWS (ECS/Fargate, S3, SES, ECR, RDS), GCP (Vertex AI, Document AI, Cloud Translation), Docker AI / LLM: OpenAI (embeddings, chat), Google Gemini / Vertex AI, Anthropic Claude, LiteLLM (multi-provider routing), Instructor (structured outputs), Langfuse (LLM observability) Auth: WorkOS (AuthKit, JWT) Observability: Sentry, Prometheus, Langfuse, structlog Tooling: GitHub Actions CI/CD, UV (Python), Bun, Ruff, mypy, ESLint, pre-commit, pytest, Drizzle ORM, SQLAlchemy 2.0 (async) What you'll do Architect and implement responsive, high-performance user interfaces with Next.js 16 and React Design and build secure, high-performance RESTful APIs in FastAPI (Python) and Hono (TypeScript/Bun) Drive the active migration from our Python backend to the TypeScript/Hono architecture Model and optimize relational schemas in PostgreSQL 17, including pgvector embeddings for semantic search Build and maintain Redis-backed caching layers and async task patterns Orchestrate multi-provider LLM calls via LiteLLM, integrating OpenAI, Gemini/Vertex AI, and Claude Instrument LLM pipelines with Langfuse for observability, cost tracking, and quality evaluation Containerize services with Docker and deploy to AWS ECS/Fargate and GCP (Vertex AI, Document AI) Build and maintain CI/CD pipelines in GitHub Actions with 100% diff-coverage enforcement Research, design, and implement autonomous AI agents that orchestrate tasks and workflows using LLMs and custom policies Ensure fault tolerance, high availability, and scalability across distributed systems; identify and mitigate bottlenecks Partner with product, design, and QA to deliver end-to-end features Conduct code reviews and champion best practices What we are looking for 5+ years of professional experience in full-stack development Proficiency with Next.js, React, and TypeScript, including SSR, app router, and server components Deep experience building Python APIs with FastAPI (or equivalent async framework) Strong TypeScript skills, with experience in Hono, Express, or similar server frameworks Strong SQL skills and hands-on experience with PostgreSQL, including advanced features (partitioning, indexing, full-text search) Experience with vector databases or pgvector for embedding storage and semantic search Familiarity with Redis for caching and async coordination Solid AWS expertise (ECS/Fargate, S3, SES, ECR, RDS); GCP exposure a plus Experience with containerization (Docker) and CI/CD pipelines (GitHub Actions) Demonstrated knowledge of distributed systems principles (consistency models, backpressure, graceful degradation) Excellent communication skills and ability to work asynchronously Bonus Prior exposure to agentic AI frameworks or building autonomous agents Experience with LiteLLM, Instructor, or other LLM orchestration libraries Hands-on Langfuse or other LLM observability tooling (Helicone, Braintrust, etc.) Familiarity with GCP services: Vertex AI, Document AI, Cloud Translation Experience with WorkOS or similar auth platforms Background in observability (Prometheus, Sentry, CloudWatch) Familiarity with infrastructure-as-code (Terraform) Contributions to open-source projects or technical communities Who you'll work with Kai (Co-Founder / Product) Fatih (Co-Founder / Revenue) Our senior engineering team Why join PLACED Build real AI systems, not just GPT wrappers Apply cutting-edge machine learning and LLM techniques to real business problems Work with founders, not layers of management Influence AI strategy and product direction from day one See your work live with real customers, fast Competitive package (salary + VSOP) Urban Sports Club membership + other perks (help us design them!) Two offices, in Berlin Mitte and Potsdam-Babelsberg: work from either one, hybrid with at least 3 days a week on site The role isn't for you if... You prefer managing over building You wait for detailed specs You're not interested in understanding the customer's business logic Placed Technologies GmbH · Schönhauser Allee 180 · 10119 Berlin Find more English Speaking Jobs in Germany on Arbeitnow