Senior AI/ML Engineer – LLM Product Features

About the role

Flo Health is building the next generation of AI‑powered, privacy‑first digital health experiences for women. We are looking for a Senior AI Engineer with strong LLM and product engineering expertise to join our AI Platform team and ship AI‑driven features across the app.

Key responsibilities

• Design, develop and ship LLM‑powered product features such as AI‑generated push notifications, personalized in‑app content recommendations and conversational insights.
• Optimize latency and user experience through streaming, pre‑generation and inference‑time trade‑offs.
• Iterate on prompt design, fine‑tune health‑domain models (Llama, Gemma, MedGemma) and ensure safe, high‑quality outputs using the Judge‑as‑a‑Service ecosystem.
• Enable A/B testing for model and prompt changes and contribute to synthetic Q&A generation, golden test sets and evaluation datasets.
• Support infrastructure work on Databricks, AWS (EKS), Terraform and CI/CD pipelines as needed.

Required profile

• 7+ years of software engineering experience with recent hands‑on work building product features backed by large language models.
• Proven ability to ship user‑facing AI features with attention to latency, tone and output quality.
• Comfortable learning and using new infrastructure tools such as Databricks, AWS, Terraform and GitHub Actions.

Required skills

• Strong Python programming.
• Experience with LLM prompt engineering, evaluation, fine‑tuning or model serving.
• Working knowledge of AWS services (including EKS) and Terraform.
• Familiarity with Databricks, Spark, Delta tables and Parquet.
• Use of CI/CD tools such as GitHub Actions.

What we offer

• Competitive salary (£120,000‑£180,000) with annual reviews and performance incentive scheme.
• Hybrid work model (3 days in‑office per week) plus generous paid holidays, parental leave and a 5‑week fully paid sabbatical at the 5‑year anniversary.
• Access to Flo Premium for friends & family and a range of health, pension and wellbeing perks.