Senior AI/ML engineer
Flo Health3 months ago
London, United KingdomSenior
Responsibilities
- Build and ship LLM-powered product features such as AI-generated mobile push notifications, personalized content recommendations, custom user journeys, conversational insights, charts, and widgets.
- Improve perceived and actual AI response latency through streaming, pregeneration, and inference-time tradeoffs while collaborating with Product and Design on user experience.
- Iterate on prompts, calibration, fine-tuned health-domain models, and Judge-as-a-Service tooling to maintain safe, relevant, and high-quality outputs.
- Enable A/B testing for model and prompt changes using evaluation gates to measure impact and support safe releases.
- Create synthetic Q&A data, golden test sets, and evaluation datasets for AI features.
- Contribute to Databricks, AWS, Terraform, and CI/CD infrastructure work as initiatives require.
- Collaborate with Product, Security, Analytics, Medical teams, and technology partners on relevant pre-release capabilities.
Requirements
- 7+ years of software engineering experience with recent hands-on experience building product features backed by LLMs.
- Experience with at least one of prompt engineering, LLM evaluation, fine-tuning, or model serving.
- Strong Python skills and comfort with APIs and SDKs that wrap LLM calls, prompt templates, and structured outputs.
- Demonstrated track record of shipping user-facing features with attention to AI-output latency, tone, and quality.
- Ability to learn infrastructure tools such as Databricks, AWS, Terraform, and GitHub Actions as needed.
- Preferred experience with LLM evaluation frameworks, judges, graders, calibration methodology, fine-tuning techniques, DSPy or similar prompt-optimization frameworks, feature stores, personalization or ranking, healthcare or regulated AI, and data engineering fundamentals including Spark, Delta tables, and Parquet.
Benefits
- Annual salary range of £120,000–£150,000 GBP, with annual reviews and eligibility for Flo’s performance incentive scheme.
- Paid holiday, sick leave, female health leave, and enhanced parental leave and pay.
- Professional growth through mission-driven work and learning support.
- Hybrid work model with three days per week in the office.
- Five-week fully paid sabbatical at the five-year Floversary.
- Flo Premium for friends and family plus health, pension, and wellbeing perks.
Tech Stack
Categories
About Flo Health
Flo Health builds a mobile app for menstrual cycle, ovulation, fertility, and pregnancy tracking, offering AI-powered insights and a private community on iOS and Android. The company operates a freemium model with optional premium subscriptions and health content. Founded in 2015 and headquartered in London, this privately held firm reports tens of millions of monthly active users, and its privacy-focused Anonymous Mode was named one of Time’s Best Inventions of 2023.