Senior/ Lead iOS Engineer

400M+ downloads. 75M+ monthly users. A decade of building – and we’re still accelerating.

Flo is the world’s #1 health app 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 6M 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

Our engineers aren’t just building a better product; they’re making the world a better place by improving women’s health. We leverage machine learning and AI to provide accurate cycle predictions and relevant, personalized, medically credible health tips. We are committed to discover and empower our employees to implement brand-new solutions.
Flo is a place for experimentation and implementation opportunities at the senior level. Flo is not just a feature factory, we own value delivery end to end. Flo is a constantly evolving product. New features and technologies are added, hardening development. Our engineers have an average of 10 years of experience, so they can solve ambitious product tasks.

You can read more about the tech stack we use and the thinking behind it here:

• At least 6 years in software engineering, including 3 years of experience developing, shipping, and maintaining mobile applications.
• Ability to demonstrate expert-level knowledge of iOS.
• Experience developing large mobile applications with rich UI, preference to global consumer markets.
• Proficient in Swift and Objective C with strong object-oriented design skills.
• Experience with Apple technologies, development guidelines, App Store processes for app submission and maintenance.
• Good understanding of a mobile product life cycle; acquaintance with Agile methodologies.
• An agile mindset, ambitious, motivated and a good team player.

Nice to have:

• Knowledge of UX and Interaction design.
• Optimizing data usage over mobile networks and experience with offline first apps.
• Experienced with mobile continuous delivery tooling (build, test and release automation).
• Integration with BI and analytical systems. AB testing.

What you\’ll be doing

You\’ll be responsible for:

• Modern frameworks and libraries along with in-house components.
• Spicy user experience and attractive design.

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Annual Salary Range (ranges may vary based on skills and experience)

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.

What you\’ll get

We support impact with meaningful reward. Here’s what that looks like:

• 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
• Flexible office + home working, up to 2 months a year working abroad
• 5-week fully paid sabbatical at 5-year Floversary
• Flo Premium for friends & family, plus more health, pension and wellbeing perks

Diversity, equity and inclusion

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 .

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