Senior Full Stack Engineer (Remote - DE/UK/PT) (m/f/d) in London

Carbon management solution to help enterprises continuously control, reduce, and report their emissions.

About us - Join our mission to fight climate change. Do you want to be part of one of Europe's fastest-growing climate tech startups? We are looking for a Senior Full Stack Engineer with a strong growth mindset to tackle the day-to-day challenges of building and growing a business. In this unique role, you’ll be a hands-on product engineer, using our state-of-the-art tech stack to solve real user problems that will positively impact the sustainability of our climate. If you’re excited about building an economy where every company creates an impact for a sustainable world and empowering companies to decarbonize and boost their business performance, we’d love to hear from you!

We are open to hiring fully remotely for this role but require you to be located in one of the following countries: Germany, United Kingdom or Portugal.

What you’ll do:

• Take responsibility for the full software development lifecycle, i.e. you design, implement, test, QA, deploy and maintain new and existing features.
• Contribute to improving the Cozero product by being a sparring partner to our product managers.
• Make architecture decisions as a key member of our engineering team.
• Participate in discussions on how to maintain and improve our micro-service architecture.
• Work closely with our other engineers to identify and mitigate tech debt.
• Contribute to driving technical innovation and finding sustainable solutions for technical challenges such as:

• Upscaling every part of the application to be able to process large amounts of data.
• Further developing the setup for data pipelines and data warehousing to enable near-real-time data processing and generation of insights.
• Driving the integration of AI solutions together with our data team.

We think you’ll thrive in this role if:

• You bring 5+ years of relevant hands-on experience in product development across our stack, including Frontend (React, Redux), Backend (NestJS), and Data (PostgreSQL).
• You write well-structured and high-quality code that’s easily maintainable by others.
• You are curious about new technologies including AI, and ideally bring some experience on how to use AI to make the development process more efficient.
• You are passionate about ClimateTech and have a strong commitment to fighting climate change.
• You are self-driven and capable of working with minimal supervision.
• You are fluent in English with excellent written and spoken communication skills.

Why join Cozero?

• Real impact - Your work directly reduces carbon emissions at scale. Not theoretical, actual tons of CO2.
• Right timing - Series A funded (€6.5M from Kvanted and ENV), growing fast, working with enterprise customers who trust us with their decarbonization journey.
• Exceptional team - Work directly with our founders Helen, Fabian, and Tiago. Multicultural, collaborative, and actually passionate about climate action—not just talking about it.
• You’ll grow fast - Flat hierarchy. Your ideas ship. Direct impact on product and strategy.

Where you’ll work

This role can be fully remote within Germany, Portugal or the UK.

Compensation & Benefits

Salary Range €60.000 - €90.000 per year (depending on experience and location). We publish our salary bands publicly so everyone, including our team, can see we’re being fair and transparent. During interviews, we’ll talk through where you’d land in this range based on your experience.

Benefits

• 27 vacation days + 1 day life event leave (Wedding, Birth of child etc.)
• 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.