As a Full-stack Engineer at Sumary, you will build, refine and ship AI-native financial workflow products used by bookkeepers, controllers and finance teams across Europe.

You’ll work across the entire stack with clear ownership, high autonomy, and a direct line to the founding team.

This is a rare chance to shape a deeply technical product from the earliest stage - one that is already deployed in leading accounting firms globally.

What you will be doing

• Architect and implement features end-to-end

• Take real ownership of our codebase, balancing robustness, security and speed

• Work with technologies such as Next.js, Node.js, TypeScript, Postgres, and AI service layers

• Design and evolve our internal platform, from data pipelines to workflow engines

• Drive continuous improvement and challenge us, the product and yourself

• Collaborate directly with founders, users and accounting firms to shape the real workflows we automate

Who you are

• A passionate engineer with 3-5 years of experience building real products end-to-end

• Comfortable across the entire stack

• You are autonomous, resourceful and thrive with ownership

• A problem solver who can think holistically about system design

• Experience with infrastructure, integrations, or financial/ledger data is a plus (but not required)

• Curiosity about AI, agents and ML-powered workflows is very welcome

Why this role

• Build foundational systems in a massive category ready for transformation

• Ship fast and see immediate real-world impact from bookkeepers and finance teams

• Join early, influence architecture, culture and engineering standards

• Work directly with second-time founders backed by byFounders, Partech, Tenity and top angels

• Help define what autonomous finance looks like in the coming decade