Senior Full-Stack Engineer (ML & Data) Stockholm - Hybrid
About this role
Senior Full-Stack Engineer (ML & Data)
Own our prediction models from training pipeline to customer-facing feature. Strong applied ML — calibration, evals, leakage — plus full-stack TypeScript to ship it.
We build AI agents that audit and optimize e-commerce advertising. Our platform syncs live data from Google Ads, Meta, Merchant Center, and Google Analytics, runs it through a rule engine, LLM-powered audit agents, and our own prediction models, and turns findings into concrete actions marketers can apply with one click.
What sets us apart is measurement: we connect real profit data from our customers' e-commerce platforms to their ad accounts and build models that tell them what their marketing actually returns — not what ad platforms self-report. The ML in our product isn't decoration. Prediction models, calibration, and evaluation pipelines are core to what customers pay for.
We're a small team shipping fast on a modern, strictly-typed stack. You'd report directly to the CTO, with real ownership: features you design end-to-end, and models you own from training data to the number a customer sees on screen.
Responsibilities
- This is a hybrid role — roughly 60% product engineering, 40% ML & data science. You'll ship full-stack features in our TypeScript monorepo and own prediction models as production software: framing the problem, building training and evaluation pipelines, monitoring calibration drift, and wiring outputs into the product.
- We're not looking for a research scientist, or a pure web engineer. We want someone who treats a model the way a good engineer treats a service: tested, monitored, versioned, and honest about its failure modes.
- Own prediction models end-to-end — models that predict product returns and net profit per order — training data pipelines, feature engineering, evaluation (ranking quality and calibration), recalibration strategies, and serving model output into the product.
- Build and maintain data pipelines — SQL feature builders o