Lead Software Engineer (m/f/d) – Python & AI

As Lead Software Engineer – Python you will shape the technology of einhundert. You build automations for our rooftop-PV-on-apartment-buildings business, drive AI-powered software development and provide technical leadership to 5-8 developers. Work remotely (EU workation) or hybrid from Cologne or Berlin.

Your responsibilities

• Set quality & security standards and champion clean-code culture
• Lead code reviews, mentor engineers and act as technical sparring partner
• Create reference implementations and AI agents
• Establish formats such as code katas and AI training sessions
• Translate complex business problems into technical solutions
• Co-design architecture and embed AI into the SDLC

Required skills

• Expert-level typed Python 3.x, KISS/YAGNI, everything-as-code mindset
• Full SDLC experience, ideally mentoring or team-lead background
• Secure-coding practices, test automation (pytest, Hypothesis)
• Scale-up mentality without enterprise overhead; startup experience a plus
• Interest in AI tools (GitHub Copilot, OpenAI Codex, Claude Code, MCP)
• Very good written and spoken German and English

Tech stack

Python 3.13, uv, mypy/pyright, pytest, Hypothesis, Terraform, GitHub Actions, Windmill on AWS, PostgreSQL, DuckDB

Benefits

• Real sustainability impact: accelerate PV roll-out on multi-family homes
• Flexible hours, 30 days vacation + birthday off, mobile work, EU workation, sabbatical option
• Mobility & health budget, company bike or Germany ticket, company pension, Urban Sports Club, mental-health platform
• Free drinks in Cologne-Ehrenfeld and Berlin offices

We welcome your application regardless of age, gender, origin, disability or sexual identity.