Senior Machine Learning Engineer - Messaging Platform
At a glance
Senior Machine Learning Engineering role at Spotify. London · no salary stated · we estimate £125,500–£152,500.
Spotify has not published a salary for this role. The figure below is our estimate, not theirs.
aimlroles summary, based on the employer's posting.
What you'll do
- Create and launch models that select messages for push, email and in-app delivery
- Design A/B tests balancing conversion, engagement, retention and reachability, then evaluate the outcomes
- Help build reinforcement learning systems aimed at longer-term user results
- Guide models from data and development through release, monitoring and continued refinement
- Link models with upstream domain signals and systems that identify messaging opportunities
What you bring
- You have built and put machine learning models into production at scale
- You have tackled ranking or other demanding optimization work with competing objectives
- You have hands-on PyTorch skills and experience with Ray or comparable distributed systems
- You can create reliable experiments and analyze outcomes using causal inference or metric breakdowns
Who this fits
This senior role suits an engineer who can turn business questions into ML solutions and discuss trade-offs with product, data science and engineering partners. You should be comfortable working across disciplines and helping set direction when problems are ambiguous. The role is based in London or Stockholm, with some in-person meetings and flexibility to work from home.
From the employer
The Messaging Platform powers Spotify’s communications to over a billion users — from push notifications to emails and in-app messages that connect listeners to the content they love. Within this space, the Paloma squad focuses on message optimization: deciding which message reaches which user, through which channel, and at what moment.
We’re evolving how messaging works at Spotify — moving from short-term optimization toward systems that understand long-term user journeys. By combining reinforcement learning approaches with deeper domain signals, we’re expanding how machine learning shapes the entire messaging funnel.
What You'll Do
- Design, build, and ship machine learning models that optimize messaging across push, email, and in-app channels
- Plan and run A/B experiments in a multi-objective environment, balancing conversion, engagement, retention, and reachability
- Contribute to reinforcement learning systems that optimize for long-term user outcomes rather than immediate interactions
- Partner with product managers, data scientists, and engineers to define what success looks like and how to measure it
- Own the full ML lifecycle, from data and modeling to deployment, monitoring, and iteration
- Integrate ML models with upstream systems, including domain value signals and opportunity generation frameworks
- Help shape the future of AI-assisted development within the team, exploring how tools can accelerate experimentation and delivery
Who You Are
- You have strong experience building and deploying machine learning models in production environments at scale
- You are comfortable translating business problems into ML solutions and discussing trade-offs with cross-functional partners
- You have worked on complex optimization problems such as ranking systems or multi-objective decision-making
- You bring hands-on experience with PyTorch and distributed systems such as Ray or similar frameworks
- You understand experimentation deeply and can design reliable tests in environments with interacting metrics
- You are able to analyze results using approaches like causal inference or metric decomposition when needed
- You have experience with or curiosity about reinforcement learning and long-term optimization systems
- You enjoy working across disciplines and navigating ambiguity while shaping strategy and direction
Where You'll Be
- This role is based in London and Stockholm
- We offer you the flexibility to work where you work best! There will be some in person meetings, but still allows for flexibility to work from home