---
title: 'Machine Learning Engineer at Flo Health'
canonical: 'https://feeny.ai/job/machine-learning-engineer-flo-health-london-49k4c7rph7ph'
type: 'job'
last_seen: '2026-10-27'
---

# Machine Learning Engineer at Flo Health

- **Company:** Flo Health
- **Location:** London, United Kingdom
- **Compensation:** £130k–£180k
- **Posted:** 2026-10-22
- **Last confirmed live:** 2026-10-27
- **Apply:** https://job-boards.greenhouse.io/flohealth/jobs/8039864003

## Job description

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

We are looking for a Machine Learning Engineers to join Flo Health. You will be developing groundbreaking features that leverage our medical expertise, technical skills, rapid adoption of new technologies (like LLMs), product knowledge, and a deep understanding of our users’ needs. If you’re passionate about technology, especially advancements in generative AI, and driven by delivering value to users, we would love to hear from you!

## Your Experience

Must have:

- 4+ years of professional experience in the field of machine learning
- Demonstrated success in building and deploying large-scale machine learning models; experience with large-scale LLM applications is a bonus
- Ability to devise creative solutions to intricate technical challenges, including experience in systems design with the ability to architect and explain ML/LLM pipelines
- Strong Python programming skills for efficient model development and deployment
- Experience with both traditional ML and modern LLM frameworks
- Understanding of the entire ML/LLM development process, including CI/CD, version control, testing, MLOps/LLMOps, and agile methodologies
- Experience in building and managing data pipelines using tools like Apache Spark
- Excellent communication skills and ability to collaborate with diverse teams
- Commitment to responsible AI practices, including fairness, accountability, and transparency

Nice to have:

- Advanced degree in Computer Science, Mathematics, or a related field
- Familiarity with statistical and measurement fundamentals and running and evaluating AB tests
- Data visualisation skills
- Experience in the MedTech domain

## What you'll be doing

You'll be responsible for:

- Explore, develop and test complex ML/AI systems to improve female health
- Work with state-of-the-art technologies, such as most advanced LLMs and Generative AI approaches, to build solutions that are medically safe and work at scale
- Work in a fast-paced environment to quickly build and validate product hypotheses, taking end-to-end ownership of ML/AI products
- Build the future-proof infrastructure for serving Gen AI features at Flo, bringing our AI vision and strategy to life
- Constantly improve our technical capabilities by researching and implementing best practices in the context of the fastly evolving space of LLMs
- Work in a cross-functional setup alongside other engineering (ML, Backend, QA), product, and analytics teams

Annual Salary Range (ranges may vary based on skills and experience) £130,000—£180,000 GBP

## 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
- 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

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](https://flo.health/privacy-policy-for-job-applicants).

## About Flo Health

## Company Overview
- **One-liner**: Flo is a women’s hormonal health app that provides personalized, data-driven, and science-backed cycle, ovulation, fertility, and pregnancy tracking from first period to perimenopause.
- **Entity Type**: Private (Series C, raised $276.4M in total funding; reached unicorn status in July 2024)  
  [uk.linkedin.com](https://uk.linkedin.com/company/flohealth)
- **Headquarters**: London, United Kingdom (additional offices in Vilnius, San Francisco, and Amsterdam)  
  [flo.health](https://flo.health/about-flo) | [uk.linkedin.com](https://uk.linkedin.com/company/flohealth)
- **Founded**: 2015  
  [flo.health](https://flo.health/about-flo)
- **Founders**: Not publicly available

## Core Business
- **Primary industry**: Women’s health / digital health / consumer health technology
- **Target customers**: B2C – women and people who menstruate across all life stages (period, fertility, pregnancy, perimenopause)
- **Mission**: “Female health has been underfunded and undervalued for way too long. … [We] ensure you can trust Flo by verifying everything we share with our team of 120+ doctors and medical experts.”  
  [flo.health](https://flo.health/about-flo)

## Products & Services
- **[Flo App]**: All-in-one mobile application for cycle and symptom tracking, ovulation and fertility guidance, pregnancy and postpartum support, tailored health insights, and access to private health communities. Includes the **Flo Assistant** – an AI-powered feature for personalized advice.  
  [flo.health](https://flo.health/about-flo)
- **[Virtual Clinics]**: A new service area (under development) aimed at offering clinical support, as indicated by job postings for a Senior Product Designer (Virtual Clinics).  
  [Greenhouse](http://job-boards.greenhouse.io/flohealth)

## Market Standing
- **Valuation/Market Cap**: Unicorn status (valuation >$1B) achieved with its Series C round in July 2024; exact valuation not disclosed.  
  [uk.linkedin.com](https://uk.linkedin.com/company/flohealth)
- **Key Metric**:
  - Total Funding: $276.4M (9 rounds)  
    [uk.linkedin.com](https://uk.linkedin.com/company/flohealth)
  - Annual Revenue: Not publicly available (private company)
  - Users: 420 million downloads, 10 million monthly active users, 85% would recommend to a friend  
    [flo.health](https://flo.health/about-flo)
- **Notable Investors/Partners**: Not explicitly listed in search results; public partnerships include **Mayo Clinic** (studying period symptoms across 800,000 cycles) and **United Nations Population Fund** (global female health education).  
  [flo.health](https://flo.health/about-flo)
- **Growth Signals**:
  - First European female health unicorn  
    [uk.linkedin.com](https://uk.linkedin.com/company/flohealth)
  - Headcount ~450–550 (YoY growth slightly negative per LinkedIn, but actively hiring 41+ roles across engineering, marketing, product, design)  
    [uk.linkedin.com](https://uk.linkedin.com/company/flohealth) | [Greenhouse](http://job-boards.greenhouse.io/flohealth)
  - Expanding into Virtual Clinics and perimenopause content  
    [Greenhouse](http://job-boards.greenhouse.io/flohealth)
  - Available in 22 languages globally  
    [flo.health](https://flo.health/about-flo)

## Competitive Advantages
- **Medical credibility**: Team of 120+ doctors, scientists, and medical experts review all content; #1 OB-GYN recommended period tracker.  
  [flo.health](https://flo.health/about-flo)
- **AI & machine learning**: Integrated predictive algorithms for period and ovulation accuracy.  
  [flo.health](https://flo.health/about-flo)
- **Privacy-first**: Anonymous Mode allows users to track health without personal identifiers.  
  [uk.linkedin.com](https://uk.linkedin.com/company/flohealth)
- **Large, engaged community**: 420M downloads and strong word-of-mouth (85% would recommend).  
  [flo.health](https://flo.health/about-flo)

## Strategic Focus
- Expand into new health verticals (e.g., perimenopause, virtual clinics) and deepen AI personalization.
- Continue global growth (22 languages, partnerships with UNFPA and Mayo Clinic).
- Strengthen medical credibility through proprietary research and expert review.
- Scale the Pass It On Project to provide free health information to 1 billion women in underserved communities.  
  [flo.health](https://flo.health/about-flo) | [flo.health](https://flo.health/)

## Why Work Here
- **Total rewards**: Employee Share Ownership Plan (ESOP) for all employees, competitive holiday (25 days + public holidays), 30 days fully paid sick leave, 6 months fully paid maternity leave + $5,000 return bonus, 1 month fully paid paternity leave.  
  [flo.health](https://flo.health/careers)
- **Flexible work**: Hybrid model (2 days/week in office); Workation policy (work from anywhere up to 2 months/year).  
  [flo.health](https://flo.health/careers)
- **Growth & learning**: Dedicated Learning & Development budget, personal development plans, career progression from within.  
  [flo.health](https://flo.health/careers)
- **Culture**: “Servant leadership” – managers ask “What can I do for you?”; high bar for talent; mission-driven environment focused on impact.  
  [flo.health](https://flo.health/careers)
- **Locations**: Major hubs in London and Vilnius, with smaller offices in San Francisco and Amsterdam.  
  [flo.health](https://flo.health/careers)

## Sources
1. [flo.health/careers](https://flo.health/careers)
2. [flo.health/about-flo](https://flo.health/about-flo)
3. [Greenhouse job board](http://job-boards.greenhouse.io/flohealth)
4. [flo.health homepage](https://flo.health/)
5. [LinkedIn company page](https://uk.linkedin.com/company/flohealth)

## Other roles at Flo Health

- [Senior/Staff Product Designer (Virtual Clinics)](https://feeny.ai/job/senior-staff-product-designer-virtual-clinics-flo-health-london-3q61pbpkk86v) — London, United Kingdom
- [Graphic Designer](https://feeny.ai/job/graphic-designer-flo-health-vilnius-1qg4vyn2kh72) — Vilnius, Lithuania
- [Growth Product Manager - Monetisation](https://feeny.ai/job/growth-product-manager-monetisation-flo-health-vilnius-0b9xh5qksm3c) — Vilnius, Lithuania
- [Growth Product Manager – Monetisation](https://feeny.ai/job/growth-product-manager-monetisation-flo-health-london-zb0r7yjqdgr1) — London, United Kingdom
- [Product Manager - Web Onboarding](https://feeny.ai/job/product-manager-web-onboarding-flo-health-vilnius-rpsbxgstvw4j) — Vilnius, Lithuania
- [Product Manager - Web Onboarding](https://feeny.ai/job/product-manager-web-onboarding-flo-health-london-rmw7xy21jge9) — London, United Kingdom
- [Freelance Motion Designer (PL/UA)](https://feeny.ai/job/freelance-motion-designer-pl-ua-flo-health-poland-n5tp8q94rh0r) — Poland
- [Creative Strategist](https://feeny.ai/job/creative-strategist-flo-health-vilnius-azrk7srd0fat) — Vilnius, Lithuania
- [Engineering Manager](https://feeny.ai/job/engineering-manager-flo-health-vilnius-2v86rjxy6cy1) — Vilnius, Lithuania
- [Engineering Manager](https://feeny.ai/job/engineering-manager-flo-health-london-941kvj6h3wpf) — London, United Kingdom