Job Title

Founding Principal Engineer

Job Description

You own the platform behind our medical device: backend services, data, infrastructure, security and identity. A first version runs today. The work is to make 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. You work closely with the founders and our CTO.

How Python is used: the backend, the analysis that turns detections into a result, and our infrastructure scripts are Python. You write mostly Python, plus PostgreSQL and OpenTofu.

What you'll do:

• 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.

What we offer: a founding role with a virtual share option plan (VSOP), a competitive salary (we share the range in our first conversation), and flexible hours. We work from Berlin and meet in person regularly, up to several days a week. English is our working language; German isn't required. We sponsor the EU Blue Card.

To apply, send your CV to people@fertoai.com. Tell us where you're based and whether you need a visa to work in Germany.

Restrictions

• No telecommuting
• No Agencies Please

Requirements

• You've built backend platforms from scratch and run them in production, through outages, data incidents, migrations and growth.
• Database depth: indexing, locking, transactions, replication, zero-downtime schema changes, and backups you've actually restored.
• Security by default: authentication and authorisation, tenant isolation, secrets, audit logging.
• Identity: identity providers, sessions and tokens, roles and permissions, onboarding and offboarding.
• Infrastructure as code, containers, Linux, networking and cloud are everyday tools for you.
• Coding agents are part of your daily work, and you stand behind every line you ship.

Nice to have: regulated environments with audits (medical devices, health, finance), and serving ML models in production.

About the Company

Ferto turns an iPhone on a standard microscope into a lab instrument. Computer vision models locate, track and measure cells in real time, starting with semen analysis. We're a small, well-funded founding team in Berlin, founded in 2026, and we build a medical device together with clinicians and lab staff.

Contact Info

• Contact: Ferto hiring team
• E-mail contact: people@fertoai.com
• Web: https://fertoai.com/careers/principal-engineer