AI-Generated End-to-End API Tests: An Experience Report in Legacy Modernization
DDD Europe - Talk (50min)
- Speakers
Cyrille Martraire and Olivier Penhoat
- Description
Legacy modernization projects remain particularly risky, even in 2026. What can AI bring to the table?
In this session, we share a concrete experience report from an AI-powered end-to-end test generation project, designed to secure the refactoring of complex APIs handling €500M in annual revenue. We'll demonstrate how we designed an AI workflow (agents with MCP) to reliably and repeatably regenerate API tests that compare complex JSON payloads exceeding 200 KB.
Moreover, through a short demo, we'll show how the developer role is evolving toward designing prompts that generate prompts that generate code, the value of maintaining strict code quality standards, and how sub-tasks with dedicated contexts can reduce AI costs over time. And because we're in DDD Europe, we'll connect what we learned to Domain-Driven Design practices!
About Cyrille Martraire (he/his)
Cyrille Martraire is CTO and co-founder at Arolla, a consultancy of 130 developers specializing in modern software practices. He's the founder of the Paris Software Crafters community in 2011 and has since been a regular speaker at international conferences. With 25+ years of experience, Cyrille now helps scale-ups and corporations as a consultant and trainer on evolving and modernizing systems to be more modular. Cyrille is the author of the book Living Documentation (Addison-Wesley Professional, 2019) and co-author of Software Craft (Dunod, 2022, 2025).About Olivier Penhoat
Passionate about web development and IT architectures, experienced in agile team management and coaching, able to create a digital platform from Think stage, to Build, Devops and Run.
