Principal Infrastructure Engineer

500M+ downloads. 80M+ monthly users. A decade of building – and we’re still accelerating.

Flo is the world’s #1 health & fitness app worldwide on a mission to build a better future for female health. Backed by a $200M investment led by General Atlantic, we became the first product of our kind to reach a $1B valuation in 2024 – and we’re not slowing down.

With 7M paid subscribers and the highest-rated experience in the App Store’s health category, we’ve spent 10 years earning trust at scale. Now, we’re building the next generation of digital health – AI-powered, privacy-first, clinically backed – to help our users know their body better.

The job

More than 80 million women open Flo every month to understand their bodies and their health. Every one of those sessions runs on infrastructure we build, and the data behind it is as personal as data gets. Keeping that fast and private at this scale is the job.

Velocity runs the platform that every Flo engineer builds on: Kubernetes on AWS, the data stores behind our services, and the golden paths that let product teams ship without needing to be infrastructure experts. We treat our internal developers as our customers. You will:

Own the foundations: Design and run the Kubernetes and data infrastructure behind 80 million monthly active users, and make it boring in the best sense.

Turn expertise into self-service: Take what you know about running clusters and databases well, and build it into the defaults so product teams get it for free.

Data infrastructure awareness: You understand how PostgreSQL, DynamoDB and Kafka behave under load and when they fail: connection limits, replication lag, hot partitions, consumer lag, retention. You don't need to have been a DBA, but you know what good looks like and when to ask for help.

How we work

• We’re a mission-led, product-driven team. We move fast, stay focused and take ownership – from brief to build to impact. Debate is encouraged. Decisions are shared. We care about craft, ship with purpose, and always raise the bar.
• You’ll be working with people who take their work seriously, not themselves. It takes commitment, resilience, and the drive to keep going when things get tough. Because better health outcomes are worth it.

Our strength is in our differences. At Flo, hiring is based on merit, skill and what you bring to the role – nothing else. We’re proud to be an equal opportunity employer, and we welcome applicants from all backgrounds, communities and identities. Read our privacy notice for job applicants.