Senior Backend Engineer - Kotlin (m/f/d) - English speaking

Doctolib

What we do Join a team of passionate and hardworking entrepreneurs to transform healthcare! Working in the tech team at Doctolib involves building innovative products and features to improve the daily lives of care teams and patients. We work in feature teams in an agile environment, while collaborating with product, design, and business teams.   What you'll do We are looking for a Senior Software Engineer FullStack to join the FIRE (FHIR & Interoperability Requirements EHR) team in the Clinical domain. As a Senior Software Engineer, your mission will be to ensure that Doctolib DE is well connected to the German digital health ecosystem and compliant with FHIR standards. You will be responsible for the interoperability of the German EHR (Electronic Health Record): connection to the Telematik-Infrastruktur (TI), electronic prescriptions (eRezept), qualified electronic signature (QES), connected medical devices (GDT), and integration of laboratory results.   Your responsibilities include but are not limited to: * Build and maintain the integration with German governmental health services, ensuring other Doctolib teams can seamlessly interact with the German health system through your platform * Drive the integration of the national EHR (Electronic Health Record) into Doctolib, with a multi-country rollout approach, navigating each country's standards and technical constraints * Design, ship, and operate production-grade fullstack solutions that connect the Doctolib platform to complex healthcare infrastructure * Partner with other engineering teams to shape the architecture of Doctolib's interoperability platform * Ensure privacy, security, and compliance by design in one of healthcare's most regulated technical environments * Own performance, observability, and reliability: monitoring dashboards, SLO/SLI, and system health * Contribute to cross-functional initiatives that shape Doctolib's future interoperability strategy across Europe   About our tech environment * Our solutions are built on a single, fully cloud-native platform that supports web and mobile app interfaces, multiple languages, and is adapted to country and healthcare specialty requirements. * The FIRE team works on a FullStack scope: React / TypeScript on the frontend and Kotlin on the backend. * Our broader stack is composed of Rails, TypeScript, Java, Python, Kotlin, Swift, and React Native. * We leverage AI ethically across our products to empower patients and health professionals. Discover our AI vision here!   Who you are Are you convinced that you have exactly what it takes for the position? Then we encourage you to apply. Even if you don't meet every requirement, you might be exactly the right future Doctoliber for this or other positions! Before you read on, if you don't have the exact profile described below, but you feel this job description matches your skill set, we still encourage you to apply. * You have 6+ years of experience as a software engineer, with strong fullstack expertise, particularly in Kotlin and React/TypeScript * You have a track record of building robust, end-to-end solutions that balance technical excellence with intuitive user experiences * You are able to design systems (system design) and make sound architectural decisions in complex environments * You understand and promote best practices related to the software development life cycle: automated testing, CI/CD, and DevOps practices (you build it, you run it) * You are curious, autonomous, and have a taste for exploring new systems : you are comfortable solving problems without complete documentation * You are at ease in complex technical environments with many external dependencies and evolving standards * You are eager to share your knowledge and help the team grow through pair programming and mentoring * You are comfortable speaking and writing in English in your day-to-day with the team, German is a plus Now, it would be fantastic if you: * Have experience with healthcare interoperability standards, particularly FHIR, HL7, or similar * Have experience integrating with governmental or regulated health systems (e.g. Telematik-Infrastruktur, eRezept, GDT) * Are familiar with the German digital health ecosystem   What we offer * A Deutschlandticket (Germany-wide public transport pass) fully paid for by Doctolib * 28 vacation days + 1 additional day for each full calendar year of employment (up to a maximum of 30 days) * Work from abroad for up to 10 days per year thanks to our flexibility days policy * Company health insurance with great supplementary benefits through our partner Allianz * Company pension scheme (bAV) through Allianz with an employer subsidy of 40% (15% within the probationary period) * Enrollment in Doctolib's long-term employee value sharing plan called DoctoGrowth * The Doctolib Parent Care program, which includes one month additional parental leave and much more * Free mental health and coaching services through our partner Moka.care * Subsidized sports membership through our partner Urban Sports Club * A flexible workplace policy offering both hybrid and office-based mode * Alongside healthy snacks and our regular breakfast buffet, we provide a subsidized meal benefit * For caregivers and workers with disabilities, a package including an adaptation of the remote policy, extra days off for medical reasons, and psychological support   The interview process * Recruiter Interview * Feature Building Interview * System Design Interview * Behavioral Interview * Reference check * Offer! Job details * Full-time * Location: Berlin * Working mode: Hybrid * Start date: as soon as possible If you would like to find out more about tech life at Doctolib, feel free to read our latest Medium blog articles! At Doctolib, we are committed to improving access to healthcare for everyone. This translates into our recruitment process. We evaluate candidates based solely on qualifications and motivation, without any form of discrimination. The more diverse ideas are heard, the more our product will truly improve healthcare for all. You are welcome to apply to Doctolib, regardless of your gender, religion, age, sexual orientation, ethnicity, disability. To ensure equal opportunities, we invite you to exclude personal information (e.g. pictures, age) from your applications. If you require any accommodation, please let us know for support during the hiring process.  Join us in building the healthcare we all dream of! All information provided is processed by Doctolib for application management. For data processing details, click here. Please contact hr.dataprivacy(at)doctolib.com for inquiries or to exercise your rights.

FREENOW

Location: Come and join us in Berlin! Freenow by Lyft empowers smarter mobility decisions helping people to move freely and cities to thrive. Be ready to work in a multinational, diverse, highly motivated and collaborative marketing team who strives for excellence and likes to have fun. Are you ready for your next ride? Join us as a Senior Backend Engineer to build the intelligent systems that power our support teams, drivers and passengers. You will drive the development of reliable and scalable backend services that bring our AI asset features to life end-to-end. Be ready to join a multinational, diverse, highly motivated and collaborative team who strives for excellence and likes to have fun, while building great features and products. ---------------------------------------------------------------------------------------------------------------------------------- YOUR DAILY ADVENTURES WILL INCLUDE: * Architect, build, and maintain robust backend services powering AI-driven support flows, from intent routing to automated case resolution. * Integrate and orchestrate LLMs to power AI-assisted support experiences for drivers and passengers. * Run testing and evaluations for AI agents, defining test scenarios, using evaluation tooling, and validating agent behaviour manually and at scale. * Ensure AI systems are observable and reliable through monitoring of latency, fallback rates, and output quality. * Own features end-to-end, from concept through to deployment and performance monitoring, partnering with engineers, product managers, and support teams to deliver meaningful, user-centered solutions. * Experiment with AI-enhanced tools and features to elevate our products and engineering practices. * Bring your ideas to life and help shape how we work, grow, and innovate as a team. * Actively engage in our engineering communities to share insights, mentor other engineers, and contribute to a culture built on transparency, continuous learning, and mutual respect. Our Techstack: Kotlin | TypeScript | Spring | React | AWS | Docker | Git | Kafka & more ---------------------------------------------------------------------------------------------------------------------------------- TO BE SUCCESSFUL IN THIS ROLE: * Strong hands-on backend development experience, with proficiency in Kotlin and Spring. * Experience with distributed systems, event-driven architectures (e.g. Kafka), CI/CD pipelines, and observability tooling (e.g. Grafana, Datadog, Kibana). * Experience integrating and working with LLMs (e.g. Gemini, GPT, Claude) in production systems, with familiarity with AI agent concepts, tool use and intent classification. * Experience with intent testing and evaluation of AI agents using evaluation tools and frameworks. * Owner mentality, you care deeply about quality, continuous improvement and technical mentorship. * You thrive in a self-organized, agile team that values autonomy, open communication, and purpose-driven work. * You bring creativity and a problem-solving mindset to technical challenges. * You actively use AI tools (e.g. Copilot, Cursor, Claude) as part of your day-to-day development workflow. * You communicate clearly and confidently in English, both written and spoken. ---------------------------------------------------------------------------------------------------------------------------------- BENEFITS & PERKS IN A NUTSHELL: * Flexible working arrangements * LinkedIn Learning * Sabbatical & special leave policies * WeRoad partnership * Birthday, 24th + 31st December off * Short term EU work policy * Mobility Credit * Health Insurance * Employee assistance program   ---------------------------------------------------------------------------------------------------------------------------------- DIVERSITY, EQUITY & INCLUSION: Freenow is an equal opportunity employer and we consider qualified applicants regardless of race, religion, national origin, gender, gender identity, sexual orientation, disability or age. We want you to grow and evolve, bring your true self to work.  ---------------------------------------------------------------------------------------------------------------------------------- ABOUT FREENOW: Freenow by Lyft empowers smarter mobility decisions, helping people to move freely and cities to thrive. Through our multi-mobility app, we feature broad options for everyone across 9 European markets and over 180 cities. Millions of passengers can access services including taxis, private hire vehicles, carsharing, car rental, e-scooters, e-bikes, e-mopeds, and public transport within a single app.  In July 2025 Freenow was acquired by Lyft, a global mobility platform, which connects riders and drivers for billions of rides across North America and Europe. Together, Freenow and Lyft are creating a more caring and connected world, with transportation for everyone. We are a global, diverse, highly motivated, and collaborative team that strives for excellence and likes to have fun. Ready for your next ride?

voize

🎤 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 triage * Drive the next iteration of in-house annotation tooling — UX, throughput, task-type extensibility — to the bar where vendor revisits are unnecessary * Maintain CI/CD, EKS deploys, and LGTM-stack observability for ML App; triage and fix defects * Pair with the Platform team on platform-side prerequisites (FGA proxy, OIDC) that the new training flows depend on * Mentor 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 SPAs * Strong Kotlin (or JVM) backend experience — services, ETL/data pipelines, schema design * Demonstrated 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 people * We foster an open, collaborative culture with regular team events, whether you work from our Berlin office or remotely across Germany * Become a co-creator of our success with stock options * Generous 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 courses * You 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!