Founders deserve to spend their time building companies, not dealing with accounting, taxes, payroll, and administrative work.
Kompanion is building the operating system for founders. We combine expert services with proprietary software to manage the operational side of running a company in one connected experience.
Technology and AI are at the core of everything we do. Our ambition is to make our specialists radically more efficient and rigorous, while giving founders the visibility and control they need to focus on growing their business.
About the Opportunity
We’re looking for a Senior Product Engineer to join Kompanion as the third person in Engineering and one of the first eight employees in the company.
You’ll help build the foundations of a robust, AI-native platform for critical tax, accounting, and financial workflows.
This is a hands‑on role with broad ownership. You’ll lead features end to end, work closely with Tax, Accounting, Growth, and Operations, and help shape our product, engineering standards, hiring, and technical culture.




Our stack and initial architecture are in place. Most of what comes next is still open to influence.
How We Build
Our stack includes Java, Spring Boot, Next.js, and PostgreSQL.
Engineering owns almost the full product loop: refining problems, researching the domain, writing PRDs, designing solutions, building, shipping, and validating them.
We use AI across development and inside the product, from document processing and assistants to autonomous agents.
We move fast where we can and carefully where reliability, security, and compliance matter. We avoid unnecessary architecture, excessive meetings, and working from tickets without understanding the problem.
What You’ll Be Doing
Owning features end to end, from problem definition to production and validation
Building across the stack, with a stronger focus on backend systems and business logic
Operating the platform in production and improving its reliability, performance, obser

📌 Senior Product Engineer (Barcelona)
🏢 Kompanion
📍 Barcelona