Senior AI Platform Engineer – LLM & Product

Flo; Greater London; Hybrid; GBP 120,000 - 160,000; Full time

Benefits offered by this job

Hybrid work model – 3 days in office

Learning & development support

Performance incentive scheme

Paid holiday & sick leave

Flo Premium for friends & family

Job summary

Flo seeks a Senior AI Engineer to join the AI Platform team, delivering AI-powered features such as personalized recommendations, conversational insights and AI-driven push notifications. You’ll optimize latency, safety and output quality across the product, using Databricks, AWS, and Terraform for scalable infrastructure.

You’ll collaborate with Product, Security, Analytics and Medical teams to ship highly usable, privacy-first AI that users trust, while advancing evaluation and calibration

Qualifications

• 7+ years of software engineering, 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, and comfort working with APIs/SDKs that wrap LLM calls, prompt templates, and structured outputs
• product sensibility: a track record of shipping user-facing features, with attention to latency, tone, and quality of AI output as experienced by end users
• comfort picking up new infrastructure tools (Databricks, AWS, Terraform, GitHub Actions) as needed — deep prior expertise not required

Responsibilities

• Feature development: build and ship LLM-powered product features, including AI-generated mobile push notifications, personalized in-app content recommendations and custom user journeys, and conversational AI-powered insights.
• Latency and UX: reduce perceived and actual response latency through streaming, pregeneration, and inference-time tradeoffs, working closely with product and design on how AI output is experienced by users
• Prompt and model behavior: iterate on prompt design and calibration, use fine-tuned health-domain models where relevant, and work with the Judge-as-a-Service ecosystem to keep outputs safe and high quality
• Experimentation: help enable A/B testing for model and prompt changes, using evaluation gates to ship safely and measure impact
• Data and evaluation: contribute to synthetic Q&A generation, golden test sets, and evaluation dataset design that supports the features you’re building
• Infrastructure: contribute to Databricks, AWS (EKS), Terraform, or CI/CD work as initiatives require it
• Cross-functional impact: collaborate with Product, Security, Analytics, and Medical teams, and engage with technology partners on pre-release capabilities relevant to your features

Skills

LLM features

Python

APIs/SDKs

Shipping features

Latency focus

Tools

Databricks

AWS

Terraform

GitHub Actions

Job description

Flo seeks a Senior AI Engineer to join the AI Platform team, delivering AI-powered features such as personalized recommendations, conversational insights and AI-driven push notifications. You’ll optimize latency, safety and output quality across the product, using Databricks, AWS, and Terraform for scalable infrastructure.

You’ll collaborate with Product, Security, Analytics and Medical teams to ship highly usable, privacy-first AI that users trust, while advancing evaluation and calibration