{"id":142051,"url":"https://alion.io/job/flo-health-senior-aiml-engineer","title":"Senior AI/ML engineer","company":{"id":51646,"name":"Flo Health","domain":"flo.health","url":"https://alion.io/company/flo-health","size_band":"51-200","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Greenhouse","truth_index":{"grade":"A","score":86,"open_postings":14,"ghost_share":0,"stale_share":0.571,"repost_share":0,"time_to_fill_p50_days":40,"computed_at":"2026-11-01T06:10:25Z"}},"role":"AI/ML","role_family":"AI/ML","seniority":"senior","employment_type":null,"work_mode":"hybrid","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["London, United Kingdom"],"countries":["GB"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":141000,"max_usd":251000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":49},"experience_years_min":7,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"A/B Testing","optional":false},{"name":"Amazon EKS","optional":false},{"name":"Anthropic","optional":false},{"name":"AWS","optional":false},{"name":"CI/CD","optional":false},{"name":"Databricks","optional":false},{"name":"Fine-tuning","optional":false},{"name":"Gemma","optional":false},{"name":"GitHub Actions","optional":false},{"name":"Llama","optional":false},{"name":"LLM","optional":false},{"name":"OpenAI","optional":false},{"name":"Prompt Engineering","optional":false},{"name":"Python","optional":false},{"name":"Structured Outputs","optional":false},{"name":"Terraform","optional":false},{"name":"DPO","optional":true},{"name":"DSPy","optional":true},{"name":"Feature Store","optional":true},{"name":"Kubernetes","optional":true},{"name":"LoRA","optional":true},{"name":"Model Distillation","optional":true},{"name":"PEFT","optional":true},{"name":"RLHF","optional":true},{"name":"Spark","optional":true}],"status":"live","first_seen_at":"2025-12-29T09:57:37Z","employer_posted_date":"2026-09-22","last_verified_at":"2026-11-01T02:54:59Z","board_verified":true,"closed_at":null,"days_open":306,"trust":{"level":"stale","repost_count":0,"flags":["stale"],"days_open":305},"description":"500M+ downloads. 80M+ monthly users. A decade of building - and we’re still accelerating.\nFlo 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.\nWith 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.\nThe job\nWe are looking for a Senior AI Engineer with strong LLM and product engineering experience to join our AI Platform team and help ship the AI-driven features across our app - including personalized in-app content recommendations, conversational AI-powered insights, and AI-generated mobile push notifications. You will focus on the product-facing behavior of our GenAI features (relevance, quality, latency, and safety), using the platform’s judges, fine-tuning pipelines, and evaluation tools, and contributing to infrastructure work (Databricks, AWS, Terraform) as initiatives require it.\nWhat you’ll do\nFeature 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 - including structured output such as charts and widgets\nLatency 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\n Prompt and model behavior: iterate on prompt design and calibration, use fine-tuned health-domain models (Llama, Gemma, MedGemma) where relevant, and work with the Judge-as-a-Service ecosystem to keep outputs safe and high quality\nExperimentation: help enable A/B testing for model and prompt changes, using evaluation gates to ship safely and measure impact\nData and evaluation: contribute to synthetic Q&A generation, golden test sets, and evaluation dataset design that supports the features you’re building\n Infrastructure: contribute to Databricks, AWS (EKS), Terraform, or CI/CD work as initiatives require it\n Cross-functional impact: collaborate with Product, Security, Analytics, and Medical teams, and engage with technology partners (Databricks, Google, OpenAI, Anthropic, AWS) on pre-release capabilities relevant to your features\nExperience and skills\nMust have:\n7+ years of software engineering, with recent hands-on experience building product features backed by LLMs\nexperience with at least one of: prompt engineering, LLM evaluation, fine-tuning, or model serving\nstrong Python, and comfort working with APIs/SDKs that wrap LLM calls, prompt templates, and structured outputs\nproduct sensibility: a track record of shipping user-facing features, with attention to latency, tone, and quality of AI output as experienced by end users\ncomfort picking up new infrastructure tools (Databricks, AWS, Terraform, GitHub Actions) as needed - deep prior expertise not required\nNice to have:\nLLM evaluation frameworks (judges, graders, calibration methodology) or fine-tuning techniques (LoRA, RLHF/DPO, model distillation)\nprompt optimisation frameworks (DSPy or similar)\nfeature stores or personalization/ranking experience (relevant to in-app content recommendation work)\nhealthcare, regulated-industry, or safety-critical AI systems experience\ndata engineering fundamentals (Spark, Delta tables, Parquet)\n#LI-KP1 #LI-Hybrid \nAnnual Salary Range (ranges may vary based on skills and experience)\n£120,000—£180,000 GBP\nHow we work\nWe’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.\nYou’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. \nWhat you'll get\nWe support impact with meaningful reward. Here’s what that looks like:\nCompetitive salary and annual reviews\nOpportunity to participate in Flo’s performance incentive scheme\nPaid holiday, sick leave, and female health leave\nEnhanced parental leave and pay for maternity, paternity, same-sex and adoptive parents\nAccelerated professional growth through world-changing work and learning support\nIn-person collaboration and work in a hybrid model, with 3 days per week spent in the office\n5-week fully paid sabbatical at 5-year Floversary\nFlo Premium for friends & family, plus more health, pension and wellbeing perks\nDiversity, equity and inclusion\nOur 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.","description_format":"text","description_chars":5179,"description_truncated":false,"requirements":{"experience_years_min":7,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":["Equity","Parental leave"],"hiring_locations":[{"name":"United Kingdom","iso":"GB","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Women’s Health & Maternity","Consumer Health Apps"],"lifecycle":[{"event":"open","at":"2025-12-29T09:57:37Z"}],"visa":[],"liveness":{"score":6,"band":"cold","label":"Long shot","p_open":1,"p_active":0.198,"p_room":0.28,"age_days":306,"expected_fill_days":40,"reasons":["conf:3","stale_co","velocity","win:tail","crowd:"],"computed_at":"2026-11-01T06:10:25Z"},"pay":null,"html_url":"https://alion.io/job/flo-health-senior-aiml-engineer","json_url":"https://alion.io/job/flo-health-senior-aiml-engineer.json","meta":{"generated_at":"2026-11-01T06:25:31Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","about":"Alion is a live layer of people, companies and AI agents: who they are, whether they are real and active right now, what they do and how to work with them, readable by people and by agents and paid per call.","catalog":"https://alion.io/catalog.json","usage":{"tier":"crawler_verified","counted_by":"address","units_charged":1,"used_today":9976,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-11-02T00:00:00Z"}},"offers":[{"id":"company.slices","title":"One company in depth, by slice","status":"live","price":{"credits":0.02,"usd":0.002,"plus_per_slice":{"credits":0.05,"usd":0.005}},"unit":"per company, plus each slice with data","note":"the employer in depth","call":{"mcp_tool":"get_company","arguments":{"id":51646},"rest":"https://alion.io/mcp/rest/get_company?id=51646"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fflo-health-senior-aiml-engineer"},{"id":"market.stats","title":"A market slice: pay, demand and time to fill","status":"live","price":{"credits":1,"usd":0.1},"unit":"per slice","note":"pay, demand and time to fill for this role and place","call":{"mcp_tool":"market_stats"},"human":"https://alion.io/catalog?offer=market.stats&for=job%2Fflo-health-senior-aiml-engineer"},{"id":"job.search","title":"Open jobs by role, technology, place, pay and visa","status":"live","price":{"credits":0.02,"usd":0.002},"unit":"per posting in a list","note":"similar open postings","call":{"mcp_tool":"search_jobs"},"human":"https://alion.io/catalog?offer=job.search&for=job%2Fflo-health-senior-aiml-engineer"},{"id":"company.verify","title":"Is this company real and active right now","status":"pilot","price":null,"unit":"per company","request":{"url":"https://alion.io/catalog/request","method":"POST","body":"{\"offer\": \"company.verify\", \"for\": \"job/flo-health-senior-aiml-engineer\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fflo-health-senior-aiml-engineer"}],"agent":{"mcp":"https://alion.io/mcp/jobs","mcp_open":"https://alion.io/mcp/open","next":[{"tool":"get_job","arguments":{"id":142051}},{"tool":"search_jobs","arguments":{"company":"flo.health","detail":"compact"}},{"tool":"match_people","arguments":{"job_id":142051},"note":"people open to offers who fit this vacancy"}],"note":"The same data through MCP tools: https://alion.io/mcp/open needs no sign-in (compact searches, postings, people); https://alion.io/mcp with an Alion account has everything. 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