Senior Platform Engineering - Remote (DE, UK, PT, ES)

🌍 About Cozero

Cozero is a carbon accounting platform where enterprises log, calculate, and report their CO2 emissions. Our engineering group is around 12 software and data engineers plus a DevOps Lead, split across two product squads (Insights and Engine) and a Platform squad (Infra, DevOps, Application & DevEx, and Data). We ship in two-week sprints and occasionally stand up tiger teams for the most urgent projects.

We are open to hiring fully remotely within Germany, United Kingdom, Portugal or Spain.

🖥️ About the Role

We are hiring a Senior Platform Engineer (m/f/d) to become the second senior voice in Platform, alongside our DevOps Lead, and to bridge two worlds he cannot cover alone: application-level developer experience and data engineering.

You will build the automation foundation for the manual data quality checks a single team member has held for years and is now transitioning out of. You keep our analytics layer running while planning its successor. You raise developer experience as a measurable discipline. You are hands-on, you write code daily, and you set the standard for how the engineering group builds and ships.

🎯 What you’ll do:

• Own Application & DevEx in the Platform group: developer frameworks, tooling, framework upgrades (NestJS, TypeScript ecosystem), test infrastructure, local dev flow, build pipelines.

• Build the automation foundation for Anja's manual data quality checks, pairing with Ghaith and Ghassen who own the check logic.

• Bridge DevOps and data engineering. Cover the data layer Hugo does not: Snowflake evolution, product data structures, data tooling landscape.

• Keep CubeJS running while architecting the migration off it, in partnership with the Data team.

• Raise developer experience as a discipline. Measure build times, test flakiness, PR turnaround. Reduce them.

• Cover GDPR posture on the platform side, either directly or in close partnership with whoever the founders bring in for compliance.

• Participate in the on-call rotation.

• Mentor across squads through code and design reviews. Ship golden paths, templates, and docs that reduce dependence on you.

⭐ You'll thrive in this role if you:

• Have 8+ years in software engineering with 3+ years in a senior IC role owning developer platform, developer experience, or data platform work.

• Have straddled backend and data engineering deliberately. Fluent TypeScript / NestJS, comfortable in Python, experience with a data warehouse (Snowflake, BigQuery, Redshift, or equivalent).

• Have owned DevEx as a first-class product with measurable outcomes: build times, test flakiness, PR turnaround.

• Have taken over a system from a single point of failure. You know how to do knowledge transfer well.

• Have opinions about test infrastructure at scale and can defend the choices you made in a real codebase.

• Have shipped data quality automation: Great Expectations, dbt tests, custom frameworks. You know invariants matter more than assertions.

• Are AI-native in your engineering practice (Claude Code, Cursor, or equivalent) and have views on where AI helps and where it does not.

• Communicate in writing first and are comfortable with an ambiguous, broad charter you will shape as much as inherit.

💚 Why Join Cozero?

• Real technical challenge - You're joining a growing system with real complexity. Work directly reduces carbon emissions at scale. Not theoretical, actual tons of CO2.

• Actual climate impact - Series A funded, growing fast, working with enterprise customers who trust us with their decarbonization journey.

• Exceptional team - Work directly with our founders. And 10+ engineers across Germany, Portugal and the UK. Multicultural, senior-leaning, collaborative, and actually passionate about climate action.

• You'll grow fast - Flat hierarchy. Your ideas ship. Direct impact on product and strategy.

📍 Where You'll Work

Fully remote within Germany, United Kingdom, Portugal or Spain.

🌱 Benefits

• 27 vacation days + 1 day life event leave (Wedding, Birth of child etc.) + national holidays (Depends on location).

• 500 EUR annual learning and development budget.

• 500 EUR one-time home office setup.

• 100 EUR monthly coworking budget (for those outside Berlin headquarters).

• VSOP (Virtual Stock Options) - share in Cozero's success.

• Regular team events every year

We're committed to building diverse teams and creating an inclusive workplace. We welcome applications from all qualified candidates regardless of ethnic origin, gender, religion or belief, age, or sexual identity. Our recruitment process is fair, objective, and based solely on the skills and qualifications required for this role.