Scaling code health with always on rewrites and AI
Wednesday - 12:30 PM · FINS LEFT
Managing thousands of components across millions of lines of code is a massive challenge. At Spotify, we moved from manual multi-month migrations to a fleet-first mindset, using tools like OpenRewrite and AI-powered background coding agents to run automated, daily code refactorings and infrastructure optimisations.
This talk covers how we scaled to over one million automated changes, our evolution from deterministic recipes to agentic loops, and how we use test automation and LLM judges to maintain quality.
Jonatan Dahl
Staff Software Engineer
SPOTIFY
Jonatan Dahl is a staff engineer at Spotify working across Fleet Management, AI, coding agents, and developer experience. He builds tools and systems in Portal, Spotify's internal developer platform powered by Backstage, that help engineering teams move faster and operate software at scale. Jonatan is focused on how AI and intelligent automation can transform the developer experience, making everyday workflows simpler, reducing cognitive load, and helping engineers spend more time on the work that matters.
Sanjana Seetharam
Senior Product Manager
SPOTIFY
Sanjana is a senior product manager at Spotify working on Fleet Management and Soundcheck Systems. She's passionate about reducing fragmentation in tech ecosystems, building innovative solutions for developers, and collaborating with diverse and talented teams. She helped externalize the Fleet Management program in Portal, which enables teams to execute code changes across thousands of repos at once. She loves baking, traveling, and trying out new cuisines and lives in New Jersey.