Senior Backend Engineer — Python

About The Company
Our client, a venture-backed (Daniel Gross, Bek Ventures and AI Grant) AI startup in the productivity and knowledge-work space, is looking for a Senior Backend Engineer to scale and optimise their autonomous email agent platform.

About The Role
Senior Backend Engineer to scale and optimize AI email platform, design FastAPI endpoints, integrate LLMs, and mentor junior engineers in Munich.

Our client, a venture-backed AI startup in the productivity and knowledge-work space, is looking for a Senior Backend Engineer to scale and optimise their autonomous email agent platform. This is a unique opportunity to work on cutting-edge AI and machine learning applications while shaping the architecture of a fast-growing product used by thousands of users.

As a Senior Backend Engineer, you will drive the performance and scalability of the real-time email ingest and synchronisation pipeline. You'll make key architectural decisions, integrate large language models (LLMs), and deliver production-ready features at startup speed.

Key Responsibilities

• Design & build high-throughput FastAPI endpoints and async pipelines for email ingest, agent execution, and user-facing services.
• Optimise PostgreSQL schemas, indexes, and partitioning to maintain low latency at massive scale.
• Integrate and refine LLM tool-calling flows, monitoring latency, quality, and cost.
• Maintain and improve CI/CD pipelines to ensure reliable, rapid deployments.
• Maintain clean data models and migration paths as product requirements evolve.
• Own production code—debug, profile, and iterate quickly.
• Mentor junior engineers, review code, and help shape technical standards and roadmap priorities.

What You'll Gain

• Competitive salary + meaningful equity in a venture-backed startup.
• Direct impact on product architecture, AI workflows, and company culture.
• Opportunity to work with engineers experienced in large-scale foundation model training.
• Fast-paced, collaborative environment where experimentation and innovation are encouraged.

Requirements

• 3+ years professional experience in modern Python
• Production experience with FastAPI or equivalent Python frameworks
• Strong practical knowledge of PostgreSQL
• Demonstrated interest or experience in AI/ML technologies
• Experience integrating external APIs and webhooks
• Excellent written and verbal English communication
• Willingness to work primarily on-site in Munich
• Experience using Cursor or Claude-Code (preferred)
• Background in early-stage product startups (preferred)
• Hands-on experience tuning LLMs for latency, cost, and quality (preferred)

Required Skills

• Python
• FastAPI
• Pydantic
• PostgreSQL
• LLMs
• Modal
• AWS
• CI/CD
• async/await
• schema design
• query planning
• performance tuning
• external APIs
• webhooks
• Gmail
• Slack
• Notion
• Google Calendar
• written and verbal English communication

Benefits

• Competitive salary + meaningful equity in a venture-backed startup
• Direct impact on product architecture, AI workflows, and company culture
• Opportunity to work with engineers experienced in large-scale foundation model training
• Fast-paced, collaborative environment where experimentation and innovation are encouraged

Equity:
equity, meaningful equity in a venture-backed startup