To catch a bug you have to think like a bug, and Barr (software programming manager) gets absolutely insectual. He gives practical tips on going beyond the debuggers by walking through the code, thoroughly understanding the code (all the code, including C, Python, Java, Perl, and x86 assembly language) and working down the food chain from the most likely to the least likely varmint that is loose in your or someone else's work. He includes classifications of bugs, their general sources, and ways to track their damage beyond the initial bite. Barr includes many examples and step-by-step methodologies.