Senior Fullstack Engineer (m/f/d)

🎤 Why voize? Because we’re more than just a job! At voize, we believe the greatest gift to frontline workers is time - time to care, connect, and be present. Today, that time is lost to busywork and complex systems that pull them away from what matters most: people. Our vision is to change that by building AI companions that seamlessly take over digital workflows. We don’t replace humans with technology - we amplify their impact. Our mission is backed with a $50M Series A funding led by Balderton Capital, with support from HV Capital, Y Combinator and other leading VCs. Today, 2,000+ facilities trust voize, and over 200,000 users rely on our AI companion to ease their daily workload. As a dynamic team, we combine first-in-class technology with meaningful social impact. And now, we’re looking for you to join us on this mission! 💡 Your Mission As a Senior Fullstack Engineer at voize, you will be a co-owner of voize's ML App — the in-house platform for annotation, data exploration, ML training orchestration, model evaluation, and the HIPAA-bearing data flows that move PHI from customer to model. Make in-house tooling good enough that revisiting Labelbox/Encord-style vendors is permanently off the table, and unblock HIPAA-compliant training on US customer data. 🚀 Your Daily Business - No two days are alike Co-own the ML App codebase (React/TS SPA + Kotlin services + Kotlin ETL on EKS)Design and ship features for data labelling, data exploration, ML training orchestration, model evaluation, model playgrounds, and ML-issue triageDrive the next iteration of in-house annotation tooling — UX, throughput, task-type extensibility — to the bar where vendor revisits are unnecessaryMaintain CI/CD, EKS deploys, and LGTM-stack observability for ML App; triage and fix defectsPair with the Platform team on platform-side prerequisites (FGA proxy, OIDC) that the new training flows depend onMentor and code-review across ML App; share conventions with adjacent teams (Mgmt App, Data, Platform) 🤝 Your Skillset - What you bring to the table 5+ years building production fullstack web apps with React + TypeScript SPAsStrong Kotlin (or JVM) backend experience — services, ETL/data pipelines, schema designDemonstrated ownership of a complex, production-critical system as a senior peer (not solo)Comfortable engineering with regulated / sensitive data (HIPAA, GDPR, BAA, PHI, or similar)Strong product / UX instincts (annotation, labeling, data exploration, ops UI)German proficiency at B2 level or above, and fluent in English 🌱 Growing together - what you can expect at voize We are a fast-growing startup, that means you will tackle challenges, grow quickly, and make a real impact, giving frontline workers more time for peopleWe foster an open, collaborative culture with regular team events, whether you work from our Berlin office or remotely across GermanyBecome a co-creator of our success with stock optionsGenerous perks: 30 vacation days plus your birthday off, Germany Transport Ticket, Urban Sports Club, regular company off-sites, and access to learning platforms such as Blinkist and Audible, plus free language coursesYou decide when you work best, that means flexible working hours and a good hybrid set-up. ✨ Ready to talk? Apply now! 🚀 We look forward to your application and can’t wait to meet you – no matter who you are or what background you have!