Product Engineer (m/f/d) // Stackgini GmbH

We are 9 people and we build this with Siemens Healthineers, REWE, Grünenthal and other leading enterprises. At this size there is no hiding. What you ship goes to customers fast, and the people who join now set the standard for the product, the culture and the category.

The role

A Product Engineer at Stackgini owns features end to end. You take a customer problem, scope it with Product & CSM, design the solution, build it across the stack, ship it, and stay close to it after release.

You are close to users. You join customer calls, run user tests, read support context, and you use that input to decide what should exist and how it should behave. The person building the feature is expected to shape the feature.

We have more good ideas than hands. For most reasonable feature ideas the question is not whether we build them, but when. Product Engineers are the people who turn that prioritization into shipped product quickly, without lowering the bar.

The AI work

AI is core to our product, but we don't run agents for everything. We use them where they create real value. For that we built our own LLM harness from hard-earned production experience: maximum freedom for the model, without compromising on enterprise control, governance or EU data residency.

What this means for you: you work hands-on with these new technologies, you run evals instead of trusting demos, and you know how to put this stuff into production reliably. Agent output gets benchmarked against expert-curated baselines, and failure modes get named, measured and fixed. If you are obsessed with how AI systems behave, fail and improve, this is the place for you.

How we ship

• Small teams of 2 to 3 engineers around a topic. We deploy continuously to production.

• We use AI tools heavily, and you have freedom in which ones (e.g. Cursor, Claude, Codex). Around that we run a strong operating system: clear ticket context, focused branches, AI review before human review, screenshots or videos for product changes, manual product testing before release, production verification after.

• The engineer who ships a change owns it in production. If something breaks, you lead the fix.

Requirements

What we need from you

Nobody at 9 people knows everything. We hire people who dive in and own outcomes.

• 3 to 6 years of full-stack experience shipping production software people actually use.

• You can get productive in our stack fast: Kotlin/Spring Boot and Python on the backend, TypeScript/React on the frontend. You don't need to know all of it on day one, but you should get into it quickly.

• You have shipped agentic systems, side projects absolutely count. You think in tools, context and evals, not just prompts.

• Fluent English. German is a real plus because many customer calls run in German. We pair you with a German-speaking teammate when needed, but German gets you closer to users faster.

You'll stand out if

• You build with AI natively, not as an afterthought.

• You can take a vague problem to a shipped feature. You scope, decide, implement, test and iterate.

• You want to understand why people behave the way they do, and you use that understanding to make product decisions.

• You have high standards for yourself and move fast without needing to be pushed. B2B SaaS or startup experience is a plus.

Our stack

Kotlin (Spring Boot) & Python · TypeScript (React/Next.js) · PostgreSQL · AWS (Fargate, ECS) & Terraform · GitHub Actions · Azure (OpenAI) · AWS (Bedrock)

Benefits

• Attractive compensation package including employee stock options

• Hybrid work with a modern office in Berlin

• 30 days of vacation and day off on your birthday

• Budget for self-improvement and dedicated time for learning & innovation

• Home-office allowance, Deutschlandticket, gym pass

• The best popcorn in town

Ready to make an impact? Join us at Stackgini and be part of something extraordinary!