Senior Software Engineer

Senior Software Engineer

Cozero

Remote

We are looking for a Senior Software Engineer to take end-to-end ownership of a core product domain in our carbon accounting platform. You’ll be the technical authority for their area: making architecture calls, shipping features in tight cycles, and being the one who keeps their domain reliable.

This is a hands-on role - you write code daily, lead by shipping, and own your systems from design to production.

What you’ll do:

• Own a product domain end-to-end - architecture decisions, feature delivery, reliability, and operational health for your area of the platform.
• Ship features in 2-3 day cycles - break down projects into small deliverables, write tech docs, and drive them to production.
• Design and build data validation and processing capabilities - ensuring customers can trust the numbers they see
• Lead technical discovery for your projects - implementation approach, testing strategy, rollout plan, risks - reviewed by peers before development starts
• Own what you build through production - deployment, monitoring, and incident response.

You'll thrive in this role if you:

• Bring 5+ years of experience in software engineering and owning a product domain end-to-end.
• Have experience with data-intensive backend systems in B2B SaaS.
• Are a strong backend engineer fluent in TypeScript/Node.js - experienced with NestJS or similar frameworks, solid with PostgreSQL, comfortable navigating a React frontend when needed.
• Have owned a product domain before - not just implemented features, but made the architectural calls and been the person who knew how the whole thing worked.
• Care deeply about data correctness - you've built systems where wrong output is worse than no output, and you think naturally about validation and edge cases.
• Ship small and often - you're uncomfortable when PRs sit for days and you treat "in production" as the only definition of done.
• Have a DevOps mindset - you own your components from technical design to release, monitoring, and maintainability.
• Debug across layers - when something's wrong, you trace it end-to-end rather than pointing at someone else's service.
• Write clear technical documents that other engineers actually use.
• Familiarity with AWS (ECS, Lambda, SQS, Aurora).

Nice to have

• Experience with data ingestion pipelines, ETL systems, or analytics tooling (Cube.js, Snowflake).
• Experience stabilizing or rewriting legacy systems incrementally.
• Climate tech, sustainability, or compliance-grade data systems.
• Series A/B startup experience.