Full Stack AI Engineer (m/w/d)

About us Cardino is a Berlin-based company founded in 2022. We build the remarketing operating system for European fleets - the software leasing companies, rental operators and OEMs use to sell used vehicles out of their fleets under their own brand. Inspection, pricing, distribution, compliance. Live in more than ten European markets. We got here the hard way: before we were a software company, we bought and sold thousands of used vehicles ourselves. Every workflow in the platform exists because we ran it manually first and knew exactly why it was broken. We run a deliberately lean senior engineering team, which means the surface area per person is unusually large. You will own systems, not tickets: vehicle data enrichment and AI-driven ingestion, pricing and residual value models, integrations with auction and dealer networks across a dozen markets. Enterprise customers put real volume through what you ship, and you will hear about it directly. No layers between you and the people using it. About the role The work sits on a specific tension: we ship fast and lean heavily on AI to do it, and we treat contracts and interfaces as first-class - because enterprise customers run real production volume through this system and cannot absorb our breakage. Holding both at once is the job, not a compromise between them. You will shape architecture, infrastructure and engineering standards directly with the founders, and you will do it while shipping features rather than from a distance. One problem waiting for you: a vehicle reaches us as a PDF appraisal, 30 photos of uneven quality, a free-text damage note and 3 data feeds that disagree with each other. Turning that into one vehicle profile we'd stake a price on - and recognising when the sources conflict because something is being hidden - is unsolved. We have agents doing parts of it. Nothing we'd yet let run unsupervised. What you'll do Build end-to-end features across our http4k and Spring Boot backend and our React/TypeScript frontendDesign and improve multi-step AI workflows that process real-world vehicle dataWork with LLM APIs, agent architectures and evaluation tooling in productionContribute to infrastructure, CI/CD and system reliability as we scaleShape product and technical direction alongside the founders Who you are You take full ownership, from concept to deployed, working featureYou move fast, iterate constantly, and know when to shift toward robust, scalable systemsYou build with AI, not just around it - AI-native development is how you workYou are comfortable with ambiguity and energized by small-team impactYou think in euros: you understand what the team's work is worth and can weigh cost against return What you bring Strong background in software architecture and engineering, especially KotlinDeep understanding of engineering best practices and scalable system designExcellent communication skills - you can bridge technical and commercial discussions Nice to have Experience in high-growth startupsFamiliarity with cloud infrastructure and DevOps practicesExposure to automotive, fleet, leasing or marketplace domains What working here looks like Direct access to the founders - you will be in the room where product and technical decisions get made, not briefed on them afterwardsDirect contact with the enterprise customers running volume through what you buildFlat structure, short decisions, no engineering middle layerHybrid working, with a WeWork office when you want a desk and the team around youPermanent contract and 30 days of annual leave Even if you don't tick every box, we encourage you to apply. We are looking for ambitious people who want to build the infrastructure European fleets run on.