[Hiring] Senior Machine Learning Scientist @Sweatpals

Role Description

We're looking for a Senior Machine Learning Scientist to join the AI Squad and own the most ambitious ML work on our roadmap. You'll report to the Head of AI and partner closely with engineering and product to ship models that move our marketplace.

This is a high-ownership role. You'll define problems, run the science, ship to production, and measure real user impact. You won't inherit a graveyard of half-finished notebooks. You'll build the next layer of ML at Sweatpals on top of what we've already shipped:

• Semantic search
• Event tagging
• Collection ranking
• Retention models
• LLM-powered HostCopilot and Front Desk Agent

You'll spend your time on problems like:

• How do we rank events for each Pal so they discover more hosts they'd love?
• Can we predict churn early enough for HostCopilot to nudge before it happens?
• What's the right way to price a class or membership to maximize host GMV without hurting bookings?
• How do we make LLMs reliable enough to draft host campaigns, recommend events, and answer questions at a real front desk?
• How do we measure if our models actually move the marketplace, not just CTR?

Qualifications

• 5+ years of applied ML experience shipping models to production. Bonus if some of that was in marketplaces, search, or recommendations.
• Track record of taking a problem from "vague PM ask" to "shipped feature that moved a metric."
• Comfort with the full lifecycle: framing, data, modeling, evaluation, deployment, monitoring.

Requirements

• Strong Python and SQL. You write production code, not just notebooks.
• Solid foundations in at least one ML area: ranking and recommendation systems, NLP and embeddings, classical ML, LLMs and agents, or causal inference.
• Comfortable with modern LLM tooling: prompting, RAG, evaluation, tool use, structured outputs.
• Practical stats: experiment design, dealing with confounding, knowing when an A/B test is broken.
• Familiarity with our stack is a plus: FastAPI, PostgreSQL, BigQuery, FAISS, sentence-transformers, AWS, Amplitude.
• Advanced degree in ML, CS, stats, or a related field is typical. PhD or research background is a strong bonus.

Benefits

• Ownership: You'll define the next chapter of ML at Sweatpals, not maintain someone else's models.
• AI-native culture: We use Claude Code daily, ship fast, and treat AI tooling as table stakes.
• Flexibility: Remote-first, async-friendly, EU timezone.
• Compensation: Competitive salary plus early-stage equity.

Our Values

• Celebrate Diversity of Thought: We embrace different backgrounds, opinions, and ways of thinking. We don't just welcome disagreement, we believe it makes the product better.
• Be a Leader: We take initiative, speak up, and drive things forward, no matter your title. Leadership is a mindset, not a level.
• Roll Up Our Sleeves: We do what it takes. No job is too small when we're building something big.
• Embrace Adventure: We stay curious, push boundaries, and see challenges as opportunities. Startups are a rollercoaster and we're here for the ride.
• Make Excellence the Baseline: We hold a high bar for quality and follow through. Doing great work is the starting point, not the finish line.

How to Apply

Send your resume (or LinkedIn) and a short note answering:

• One ML system you shipped end-to-end and what it actually changed.
• A modeling decision you made that turned out to be wrong, and what you learned.
• A paper, blog post, or repo you keep going back to (optional, but we love this).