ALL SPEAKERS
AT A GLANCE
Role
Software Engineer
Organisation
PayFit
Category
Hero
ABOUT THE SPEAKER
Author of Architecture Modernization (Manning), Curator of legacy-modernization.io and software engineer at PayFit
TALK
Lessons learned building a harness to rediscover and replace a legacy system
Can AI help us to modernize these 3 legacy systems faster? This was the question we asked ourselves after yet another bug that forced us to dig through the many synchronization issues and data inconsistencies that comes with trying to keep 3 services in sync. It was now the time to regroup the domain logic spread across the 3 services into a single service and codebase to avoid all these difficulties, and hopefully make these expansive changes across too many code repositories a thing of the past. Removing a system out of the equation was a good experimental field to see what AI could do in terms of legacy modernization. How can AI help us to go faster, learn faster, make better decisions....? We successfully achieved the goals of the project by creating our own harness and custom tools. This included capabilities mapping out the project as a mikado graph with a custom UI, subagents for analysing code and creating diagrams of it, generating migration plans, and providing a skill that could be used by teams to migrate their parts of the code. In this talk we will talk through the pieces of our harness, including what we learned and how we applied them to the project with concrete examples. We'll also share our learnings relevant to the important question: "do humans still need to understand the AI's code changes during a legacy migration or can we trust it without reviewing every line?"
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