VP of Security & Infrastructure

Location: London; hybrid model with 3 days per week in the office

Annual salary: £200,000–£220,000 GBP

Company

Flo is a digital health product company building an AI-powered, privacy-first and clinically backed health and fitness app for female health.

What you will do

• Build and ship LLM-powered product features, including personalized in-app recommendations, custom user journeys, conversational insights, charts, widgets, and AI-generated mobile push notifications.
• Improve perceived and actual response latency through streaming, pre-generation, and inference-time trade-offs.
• Iterate on prompts and model behavior using fine-tuned health-domain models such as Llama, Gemma, and MedGemma.
• Enable A/B testing, evaluation gates, synthetic Q&A generation, golden test sets, and evaluation datasets.
• Contribute to Databricks, AWS EKS, Terraform, and CI/CD initiatives.
• Collaborate with Product, Security, Analytics, Medical teams, and technology partners including Databricks, Google, OpenAI, Anthropic, and AWS.

Requirements

• 7+ years of software engineering experience, including recent hands-on work building product features backed by LLMs.
• Experience with prompt engineering, LLM evaluation, fine-tuning, or model serving.
• Strong Python skills and experience with APIs or SDKs for LLM calls, prompt templates, and structured outputs.
• Track record of shipping user-facing features with attention to latency, tone, and AI output quality.
• Ability to learn and use infrastructure tools such as Databricks, AWS, Terraform, and GitHub Actions.

Nice to have

• Experience with LLM evaluation frameworks, judges, graders, calibration, or fine-tuning methods such as LoRA, RLHF/DPO, and model distillation.
• Experience with DSPy or similar prompt optimization frameworks.
• Feature stores, personalization, or ranking experience.
• Healthcare, regulated-industry, or safety-critical AI experience.
• Data engineering fundamentals including Spark, Delta tables, and Parquet.

Culture & Benefits

• Mission-led, product-driven environment focused on ownership, craft, experimentation, and purposeful delivery.
• Competitive salary, annual reviews, and participation in a performance incentive scheme.
• Paid holiday, sick leave, female health leave, and enhanced parental leave and pay.
• Professional growth through learning support and work on digital health products.
• Five-week paid sabbatical after five years, plus Flo Premium, health, pension, and wellbeing benefits.