Senior Fullstack Engineer

Karbon is seeking a Senior Full Stack Software Engineer to join the team working on Aider, a product within the Karbon portfolio. This is a frontend-led role with full-stack ownership and ~20% focus on backend/API work, primarily using Node.js.

Requirements

• Design, build, and maintain high-quality, customer-facing web applications using React and TypeScript, with a strong emphasis on frontend experience and performance.
• Develop and maintain backend services and APIs using Node.js, contributing to data flows, integrations, and platform reliability (~20% of scope).
• Translate product requirements into clear technical designs, balancing speed, quality, and long-term maintainability.
• Own features end to end—from discovery and implementation through deployment, monitoring, and iteration.
• Optimize user experiences through thoughtful UI/UX decisions, performance improvements, and frontend architecture.
• Use experimentation techniques such as A/B testing, feature flags, and funnel analysis to improve acquisition, activation, and retention.
• Study user behavior data to identify opportunities for improvement and refinement across the product.
• Work closely with QA, Product, and Design to ensure features are well-tested, reliable, and meet user expectations.
• Participate actively in code reviews, technical discussions, and architectural decisions.
• Take ownership of existing systems as well as new development, making iterative improvements to keep the product healthy and scalable.
• Collaborate effectively with a distributed, international engineering team in a low-politics, high-trust environment.
• Leverage AI-assisted development tools (e.g. for code generation, refactoring, testing, and documentation) to improve development velocity and code quality.
• Identify opportunities to automate repetitive engineering tasks and improve workflows across development, testing, and deployment.
• Apply AI-enabled insights responsibly when analyzing user behavior, experiments, or product performance.

Benefits

• 4 weeks annual leave plus 5 extra 'Karbon Days' off a year
• Flexible working environment
• Work with (and learn from) an experienced, high-performing team
• Be part of a fast-growing company that firmly believes in promoting high performers from within
• A collaborative, team-oriented culture that embraces diversity, invests in development, and provides consistent feedback
• Generous parental leave