Debugging is making invisible state observable
Page, logic, network, environment and performance — only when all five layers can be seen is your debugging systematic rather than lucky. With the tools and experience for each.
From symptom to root cause: a repeatable front-end debugging process
How to actually use Elements, Console, Sources, Network and Performance, how to carry a desktop investigation onto a real device, and how to turn debugging from personal skill into team process.
How to think about front-end debugging: identify the layer first
Debugging is not "log everything and hope". Logic, styling, network, performance, compatibility and WebView each have their own way in — deciding the layer first beats any tool.