{"id":80189,"url":"https://alion.io/job/posthog-ai-research-engineer","title":"AI Research Engineer","company":{"id":33807,"name":"PostHog","domain":"posthog.com","url":"https://alion.io/company/posthog","size_band":"201-500","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Ashby","truth_index":null},"role":"AI/ML","role_family":"AI/ML","seniority":null,"employment_type":"full_time","work_mode":"hybrid","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Cambridge, United Kingdom"],"countries":["GB"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":null,"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Model Context Protocol","optional":false},{"name":"Slack","optional":false},{"name":"SQL","optional":false},{"name":"CUDA","optional":true},{"name":"CUDA Toolkit","optional":true},{"name":"Jupyter Notebook","optional":true},{"name":"PyTorch","optional":true},{"name":"Rust","optional":true},{"name":"Transformers","optional":true}],"status":"live","first_seen_at":"2026-08-18T19:01:08Z","employer_posted_date":"2026-08-18","last_verified_at":"2026-10-17T16:31:40Z","board_verified":true,"closed_at":null,"days_open":59,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":59},"description":"About PostHog\nPostHog is your product’s context layer. It ingests and stores your analytics, errors, replays, and business data so you and your agents can query and act on it.\nWe launched out of Y Combinator's W20 cohort. We've since shipped more than a dozen products, including:\nA suite of analytics and observability tools, including product analytics, replay vision, AI observability, and error tracking\n\nPostHog MCP for users and their agents to query and act on their product and business data\n\nData warehouse so users can query product and customer data together using custom SQL insights.\n\nWe are:\nProduct-led. More than 500K organizations have installed PostHog, mostly driven by word-of-mouth. We have intensely strong product-market fit.\n\nDefault alive. Revenue is growing incredibly quickly, and we're very efficient. We raise money to push ambition and grow faster, not to keep the lights on.\n\nWell-funded. We've raised more than $180m from some of the world's top investors. We're set up for a long, ambitious journey.\n\nWe're focused on building an awesome product for end users, hiring exceptional teammates, shipping fast, and being as weird as possible.\nThings we care about\nTransparency: Everyone can read about our roadmap, how we pay (or even let go of) people, our strategy, and how we work, in our public company handbook. Internally, we share revenue, notes and slides from board meetings, and fundraising plans, so everyone has the context they need to make good decisions.\n\nAutonomy: We don’t tell anyone what to do. Everyone chooses what to work on next based on what's going to have the biggest impact on our customers, and what they find interesting and motivating to work on. Engineers lead product teams and make product decisions. Teams are flexible and easy to change when needed.\n\nShipping fast: Why not now? We want to build a lot of products; we can't do that shipping at a normal pace. We've built the company around small teams - autonomous, highly-efficient groups of cracked engineers who can outship much larger companies because they own their products end-to-end.\n\nTime for building: Nothing gets shipped in a meeting. We're a natively remote company. We default to async communication - PRs > Issues > Slack. Tuesdays and Thursdays are meeting-free days, and we prioritize heads down building time over perfect coordination. This will be the most productive job you've ever had.\n\nBeing weird: Weird means redesigning an already world-class website for the 5th time. It means shipping literally every product that relates to customer data. It means building an objectively unnecessary developer toy with dubious shareholder value. Doing weird stuff is a competitive advantage. And it's fun.\n\nWho we're looking for\nPostHog is working on a self-driving product and is training its own Deep ML models. To do this, we have a new AI Research team.\nWe track more products across more dimensions than any other company on Earth. Because of this, we have petabytes of data across events, errors, session replays, revenue data, and more. It’s an exceptionally large amount of data relative to our company size, and we want to use it for our users' benefit. Just imagine how, with the vast amount of data we capture, we can automatically surface insights and suggest fixes.\nAs an AI Research Engineer, you will play a substantial part in making this happen. This team is brand new, so you will have real autonomy, be close to customers, and greatly influence what we actually ship.\nOn the finance side, we have around $150M on our balance sheet, we’re \"default alive,\" and we have a real business that has been scaling rapidly and running exceptionally efficiently with good margins for six years. We invest in what we believe moves the needle.\nWhat you'll be doing\nYou'll be part of a team that researches what's next and what's better, and actually brings it into production.\nAreas we’re exploring\nSession replay analysis: We already detect issues in replays, but doing so is expensive and doesn’t scale. With better models (and a huge amount of DOM mutation data), we think we can make this faster, cheaper, and best-in-class.\n\nUser behavior prediction: Identifying drop-offs, suggesting improvements, and potentially improving conversion rates automatically without heavy manual analysis or agent overhead.\n\nSynthetic user testing: Simulating users to catch confusing flows or breakages before release. If this works, it could remove one of the biggest bottlenecks in modern engineering: testing (rather than writing code).\n\nJob Requirements\nA PhD is a plus, but a strong background in math is a must, or you have previous experience training models (strong math skills are still required).\n\nStrong PyTorch experience.\n\nStrong ability to code in Rust, CUDA, or C (with a preference for Rust).\n\nSolid understanding of Transformers (not the movies).\n\nA product mindset. you’ll be building things!\n\nThis is a unique role within PostHog and, as such, is a hybrid-remote position based out of our London office.\n\nWhat we’re not looking for\nPure theoretical expertise: this is not a Jupyter notebook job.\n\nSomeone who just wants to do research and publish. Yes, you can publish, but shipping takes priority.\n\nWe are committed to ensuring a fair and accessible interview process. If you need any accommodations or adjustments, please let us know\n#LI-DNI","description_format":"text","description_chars":5382,"description_truncated":false,"requirements":{"experience_years_min":null,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":{"level":"phd","optional":true},"security_clearance":false,"languages":[]},"benefits":[],"hiring_locations":[{"name":"United Kingdom","iso":"GB","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Product Analytics & Session Replay","A/B Testing & Experimentation"],"lifecycle":[{"event":"open","at":"2026-08-18T19:01:08Z"}],"visa":[],"liveness":{"score":37,"band":"fade","label":"Fading","p_open":1,"p_active":0.675,"p_room":0.55,"age_days":59,"expected_fill_days":51,"reasons":["conf:2","velocity","win:tail"],"computed_at":"2026-10-17T05:46:00Z"},"pay":null,"html_url":"https://alion.io/job/posthog-ai-research-engineer","json_url":"https://alion.io/job/posthog-ai-research-engineer.json","meta":{"generated_at":"2026-10-17T18:08:09Z","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":717,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-18T00:00:00Z"}},"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":33807},"rest":"https://alion.io/mcp/rest/get_company?id=33807"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fposthog-ai-research-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%2Fposthog-ai-research-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%2Fposthog-ai-research-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/posthog-ai-research-engineer\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fposthog-ai-research-engineer"}]}