If you think about Google's codebase size, an IDE wouldn't cut it. You could load and analyze dependencies/imports as you go, but that would make for a terrible

If you think about Google's codebase size, an IDE wouldn't cut it. You could load and analyze dependencies/imports as you go, but that would make for a terrible user experience (think about IntelliJ indexing task every time you want to check the definition of something). Also, Code Search has baked in a lot of goodies. History layer, cross-references, call sites, ... and it's snappy. Moreover, is really well integrated with all the other internal tools used for coverage, code analysis, issue tracking, web text editor, ... . I think an IDE (like IntelliJ IDEA) can't reach that level of integration with several other systems unless you fully buy into the ecosystem a company like JetBrain proposes you (their issue tracker, their code review tool, ...). So, summarizing, it's a tool made by Googlers for Googlers' needs and it's amazing using it every day for all the above reasons.