Senior Full Stack Product Engineer

About Shelf The enterprise is going agentic and we are creating a unique operating system for an automated future. Most AI agents break the moment they hit real business complexity. That’s why we built a platform that models a company's policies, workflows, and operational logic into an AI Data Model.

Shelf enables AI Agents to reliably reason and deliver precise and reliable outcomes at scale. We already have what most AI startups are still trying to earn: Enterprise customers such as Glovo, Nespresso, and HelloFresh, real production data, and tens of thousands of users. Customers trust us with operational knowledge: Our platform is highly reliable and secure with SOC2, HIPAA-ready security practices, and mature integrations in place.

Job Description This role is for a senior full-stack product engineer who can design and own business-critical product experiences end-to-end. We want someone who is strong technically, has sharp product judgment, communicates clearly, and has the taste to make user experiences and systems simpler, safer, and easier to evolve over time. Expect real ownership from problem discovery through frontend, backend, release, and production quality.

The team is small enough for engineers to make real decisions. Career growth comes from ownership. Titles matter less than the scope you can carry.

The people who grow fastest take responsibility for larger product areas, drive customer outcomes, and strive to develop better engineering practices. You solve ambiguous product problems by understanding the customer need, shaping the right technical and UX approach, then shipping, iterating, and keeping it healthy in production. We build AI-native.

Engineers use Codex, Claude Code, and agents they build themselves. We invest in harness engineering through skills, CLIs, logs, traces, and orchestration. This is a role for someone in a high-growth chapter of their career, who wants to do the best work of their life, learn fast, and win as part of a team going all-in on a hard mission.

Location – Warsaw, work from the office. What You Will Own Build and ship user-facing product features across frontend and backend boundaries Turn rough product goals into practical solutions with good scope, sensible trade-offs, and strong execution Work comfortably in UI, application logic, APIs, and data flows rather than stopping at team boundaries Partner closely with product and design while still being able to move when the spec is incomplete Improve usability, clarity, performance, and reliability, not just feature completeness Instrument what you ship so we can learn from production behavior and iterate quickly Use AI tools daily to move faster and help improve internal workflows, tooling, and engineering leverage Keep the bar high on code quality, testing, and ownership after launch What Strong Performance Looks Like You can take a vague product problem and turn it into a shipped, well-reasoned solution Your features feel coherent end-to-end because you care about both implementation and product quality You do not treat frontend and backend as separate worlds; you use both to solve the actual problem You bring momentum.

What We Are Looking For

Strong senior-level experience shipping production web products Strong frontend ability with React and TypeScript or an equivalent modern web stack Real backend ability. You do not need to be backend-only, but you can design and ship APIs, backend logic, and data flows when the product needs it Strong product sense. You notice awkward flows, weak defaults, and unnecessary complexity, and you improve them Good judgment about scope, iteration, and technical trade-offs A security-conscious approach to engineering: you handle sensitive data carefully and think about the security implications of what you ship Clear communication and comfort working across engineering, product, and design AI-native working style.