Founding Principal Engineer (mfd)

Most labs still count cells under a microscope by hand. Its slow repetitive and error-prone. Were replacing that manual work with software. By combining a standard microscope with a smartphone we run computer vision models that locate track and measure cells automatically in real time. Were starting with semen analysis and expanding to other routine microscopic samples. Were a small well-funded team in Berlin founded in 2026. Our goal is to make automated reliable diagnostic analysis accessible on any phone connected to a microscope.

Were looking for an engineer who wants to own the whole platform behind a medical product: services data infrastructure security and identity. A first version runs today. The hard part is making it trustworthy enough for clinical use: patient data that stays safe an audit trail that holds up for years and a system that recovers when something breaks. Youll own all of it working closely with the founders and our CTO.

• Own the platform end to end: backend data infrastructure and security.

• Get it ready for clinical use and keep it reliable as we grow.

• Build identity access and data handling that clinics and auditors can trust.

• Make the architecture calls: what to build now what to defer what to cut.

• Set the engineering standard and help hire the team that follows.

• Platforms youve built and run. Youve built backend platforms from scratch and run them in production through outages data incidents migrations and growth.

• Database depth. You know what happens under the query: indexing locking transactions replication zero-downtime schema changes and backups youve actually restored.

• Security by default. Authentication and authorisation tenant isolation secrets audit logging. You think about how a system gets attacked before it ships.

• Identity done properly. Identity providers sessions and tokens roles and permissions onboarding and offboarding.

• Infrastructure. Infrastructure as code containers Linux networking and cloud are everyday tools for you.

• Beyond the backend. The backend is your home but when the product needs it you read and change the app yourself.

• Systematic troubleshooting. You reproduce first and fix root causes. You work from evidence like logs traces metrics and query plans and you stay calm when production breaks.

• AI-native engineering. Coding agents are part of your daily work. You give them good context split work into reviewable steps and stand behind every line you ship.

• Ownership. You help shape the roadmap push back on weak ideas set your own priorities and raise problems early. Nobody has to chase you. Strong opinions held with evidence and open to revision.

• Range. Youve worked across several companies stacks or environments. How you work counts far more than how many years youve done it.

• Regulated environments with audits: medical devices health finance.

• Serving ML models in production.

• Ownership from day one. As a founding engineer youre part of the company through our virtual share option plan (VSOP).

• You grow with us. As the company grows your role grows with it.

• Real influence. You decide how we build software and you shape the engineering team we build.

• A competitive salary.

• A product that matters: a medical device for real clinics built together with clinicians and lab staff.

• Flexible hours and office days. We work from Berlin and meet in person regularly up to several days a week. This isnt a fully remote role.

• English is our working language. German isnt required.

• We sponsor the EU Blue Card if youre moving to Berlin.