As a SWE working on Google Search, I can tell you this is not the case for Google Search (Nobody understands anywhere close to 85% of it). The amount of differ

As a SWE working on Google Search, I can tell you this is not the case for Google Search (Nobody understands anywhere close to 85% of it). The amount of different moving pieces is enormous, and most parts are constantly being changed. The best you can do is to have an understanding of which system is responsible for what, and delegating to someone who is an expert in that system when you need to dig into what it is doing.