We've been experimenting with how Claude Code can help us migrate the functionality in FS-klienten (our legacy PowerBuilder application) to our new frontend FS Admin. The results are really promising and indicate that if we manage to use Claude correctly, this is a game changer.

I'll demonstrate how a team at Sikt used Claude to analyze screens in our legacy application, then plan and finally extend our existing GraphQL schema with the neccessary changes for this screen to be migrated.

Turning a private GraphQL API into a public one comes with unexpected challenges. We’ll share how we approached this transition—starting from an existing internal schema that wasn’t shaped for external consumers—and the steps we took to expose only what was ready. Using Apollo Federation Contracts, we filtered out unstable or sensitive parts of the graph. Along the way, we defined best practices for the public schema, like cursor-based pagination, using oneOf for inputs and results. We’ll also touch on how we serve the schema through Hive Gateway with a supergraph setup, and the security measures we added, like depth limiting and complexity analysis. To keep things evolving safely, we rely on GraphQL Hive to track usage and guide deprecations.

If you’re thinking about exposing a GraphQL API—or just want ideas for keeping one clean and manageable—this talk will share what worked for us, what didn’t, and what we learned.