AI Research Engineer

• Join PostHog’s brand-new AI Research team as an AI Research Engineer. • Train PostHog’s own deep learning models on petabytes of product data. • Help build a self-driving product that surfaces insights and suggests fixes automatically. • Explore session replay analysis, user behaviour prediction and synthetic user testing. • Take real autonomy, stay close to customers and ship research into production. • Work hybrid-remote from PostHog’s London office.

• Bring a strong background in maths, or previous experience training models with strong maths skills. • Show strong PyTorch experience. • Code well in Rust, CUDA or C. • Understand Transformer architectures deeply. • Bring a product mindset and a focus on shipping over pure research. • Work hybrid-remote from the London office.

• Hold a PhD in a relevant field. • Prefer Rust over CUDA or C. • Bring experience with session replay, DOM or user behaviour data. • Show experience training encoders or evaluating models against state-of-the-art benchmarks.

• Research and build models that turn PostHog’s large datasets into user value. • Make session replay issue detection faster, cheaper and best-in-class. • Predict user behaviour to identify drop-offs and suggest improvements. • Explore synthetic user testing to catch confusing flows before release. • Train, evaluate and benchmark models, then bring them into production. • Influence what the new AI Research team ships.

We have used PostHog's web analytics ourselves and genuinely loved the experience. The product is fast, thoughtfully designed, and surprisingly fun to use. PostHog is unlike most SaaS companies: their entire handbook is public, their codebase is open source, and they share revenue figures and board meeting notes with every team member. The company has raised $194M from investors, including Stripe, GV, and Y Combinator, reached a $1.4 billion valuation in 2025, and is targeting $100M in ARR by the end of 2026. They pay generously, benchmarking engineering salaries at the 90th percentile of San Francisco rates adjusted by location, with a fully public compensation calculator so you know your salary before you even apply. Employees on Glassdoor consistently highlight the flexible spending, genuine remote-first culture, and regular offsites, alongside a $1,500 quarterly budget for meeting up with colleagues anywhere in the world. Many team members are former founders, and the company is structured around small, autonomous teams that own their products end-to-end. If you are an engineer or builder who thrives on autonomy, ships fast, and wants to work on a product used by nearly 200,000 teams, PostHog is a rare opportunity.

• Earn generous, transparent compensation plus significant equity. • Take unlimited vacation, with a minimum. • Enjoy two meeting-free days a week in an async-first culture. • Get a home office budget and coworking credit. • Receive private health, dental and vision insurance and pension contributions. • Get a training budget, company offsites and access to the Hedge House.

PostHog is your product’s context layer, ingesting and storing analytics, errors, replays and business data so teams and their agents can query and act on it. It launched from Y Combinator’s W20 cohort and has shipped more than a dozen products, installed by over 500,000 organisations. PostHog has raised more than $180 million and is default alive, growing quickly and efficiently.