Company
Date Published
Author
Greg Foster
Word count
2941
Language
English
Hacker News points
None

Summary

In a blog post reflecting on the evolution of continuous integration practices, Graydon Hoare, the creator of Bors, highlights the challenges and solutions related to managing merge skew in software development. The early efforts involved using automated systems to maintain a bug-free code repository, an approach that has since evolved into the modern practice of continuous integration, where code is tested before merging to ensure stability. Despite these advancements, merge skew—when changes occur between the time a pull request is tested and when it is merged—remains a significant issue, particularly in high-velocity environments. As teams grow and the pace of merges increases, the likelihood of semantic conflicts rises, leading to disruptions in productivity. Early solutions like Bors introduced automated merge queues to tackle this problem, but they struggled with throughput. In response, companies like Google developed complex systems using batching and parallelization to handle large volumes of code changes efficiently. These practices have influenced newer tools and features from platforms like GitHub and GitLab, which now offer native merge queues that incorporate lessons from previous systems, aiming to balance correctness with speed in the merging process.