Debugging Case Study: Meta

Let's make things concrete with a clear debugging case study from Meta. Here are the core points from the lesson:

• Mastering the deployment process (web continuous deploys vs mobile gated releases) and internal tools like “Where Is My Diff” at Meta can make it faster to rule out likely causes
• Being deeply familiar with experiments, gatekeepers, and other release tooling can help you spot issues like sudden error spikes or QA/test build failures without needing to dig into the code immediately
• Effective debuggers can quickly answer questions like when a code change deployed, what experiments launched, and what version a user was on during a bug report
• Going deep into tooling and metrics, not just code, lets you identify root causes faster, communicate precisely with teams, and resolve issues much more efficiently

How Facebook does continuous deployment: https://engineering.fb.com/2017/08/31/web/rapid-release-at-massive-scale/