Working in large established codebases as a software engineer is challenging, as personal projects and open source experience do not provide the same preparation. The most crucial aspect of navigating these codebases is consistency. Ignoring existing patterns for cleaner code can lead to trouble, as large codebases are full of surprises and landmines. Understanding the production footprint, avoiding unnecessary dependencies, and prioritizing small, readable changes are key. Despite the messiness, large codebases are essential for big tech companies, as they generate the majority of the revenue. Overall, embracing the complexity and developing a deep understanding is vital for success in these environments.
https://www.seangoedecke.com/large-established-codebases/