Senior Backend Engineer

Build systems that power the #1 Health App for Women

We’re not a startup guessing what might work anymore, we’re operating at serious scale. Flo is used by 1 in 4 women aged 18–44 in the US. And we just hit our biggest month ever with 8.6M installs and a 2.8M MAU jump. The engineering behind that? Complex, distributed, secure and yours to help shape.

At Flo, backend engineering is core product work.

We build:

• Data-driven health insights that genuinely change lives
• Distributed systems that stay fast, available and scalable under massive real-time demand
• Privacy-first features like Anonymous Mode - recognised in TIME’s Best Inventions
• Tooling and platforms that help Flo’s teams move faster, with fewer bottlenecks

• Have 7+ years’ experience building distributed backend systems
• Know what it takes to make systems fast, reliable and secure and when to prioritise each
• Are fluent in Java, Scala, Python or similar (and curious enough to learn Scala with us)
• Get DevOps, databases (SQL and NoSQL) and love designing APIs that just work
• Have a strong handle on writing clean, documented, version-controlled code
• Take ownership, show initiative and don’t wait to be told
• Are product-minded and always thinking about the end-user impact

Nice to have

• Stream processing
• Public cloud infrastructure (AWS, GCP etc.)

• Competitive salary and annual reviews
• Opportunity to participate in Flo’s performance incentive scheme
• Paid holiday, sick leave, and female health leave
• Enhanced parental leave and pay for maternity, paternity, same-sex and adoptive parents
• Accelerated professional growth through world-changing work and learning support
• In-person collaboration and work in a hybrid model, with 3 days per week spent in the office
• 5-week fully paid sabbatical at 5-year Floversary
• Flo Premium for friends & family, plus more health, pension and wellbeing perks