At the level of single process, on one machine, I've found a mix of debug logs, trace points, conditional breakpoints, and the ability to execute arbitrary code

At the level of single process, on one machine, I've found a mix of debug logs, trace points, conditional breakpoints, and the ability to execute arbitrary code when at a breakpoint to be super helpful in debugging complex code with many layers. I was working on a compiler of sorts. The only time I had access to all of these was when working on C# in Visual Studio. Being able to run arbitrary code at the breakpoint-paused stack is incredibly useful. With multiple processes or machines, it's helpful to pass around a trace ID and then have all the debug logs print the trace ID + timestamp at each event. This is a rather manual process; I wish there were automatic ways of doing this. At Google, the best we get is filtering logs by the RPC being processed at the time; but this ends at a particular process. Cross-process RPC traces are mostly sampled "stack traces"; you don't get to inject custom debug messages in those.