My approach is to break stuff. If I can break it (and I am good at finding bugs, so I usually can) then I now have a narrow focus which helps me getting "lost"

My approach is to break stuff. If I can break it (and I am good at finding bugs, so I usually can) then I now have a narrow focus which helps me getting "lost" in the code base. Once I've found and fixed a few things, or if the code base is particularly small or clean that I can't find bugs to fix, I'll set about hacking in the feature I'd like. I usually start by doing it in the most hacky way possible. That sounds like a bad approach but it narrows the search of how to implement it and means I'm not constraining myself to fit the code base that I don't yet appreciate. In hacking that feature I'll often break a few things through my carelessness. In then trying to alter my hacked approach so it no longer breaks stuff I'll become more aware of the wider code base from the point of view of my initial narrow focus. This lets me build up the mental model. Eventually I'll be comfortable enough I can re-write the feature in a way more consistent with the wider code base. I don't normally start by trying to "read all the code" because that guarentees I won't understand much of it (I'm not quick at picking up function from code). I might have a skim if it is well organised, but I find the "better" written a lot of stuff is, the harder it is to grok what it is actually doing from reading it. to me, reading good code is often like trying to read the FizzBuzz Enterprise Edition[1]. I've worked on many legacy systems: I was last year implementing new features into a VB6 code base, this year (at a different job) I am helping migrate from asp webforms to a more modern system. I've found that starting with trying to fix an issue to be the best way to dive into the code base. Use good source control so you're never "worried" about changing anything or worrying that you might lose your current state. Commit early, commit often, even when "playing around". [1] https://github.com/EnterpriseQualityCoding/FizzBuzzEnterpriseEdition https://github.com/EnterpriseQualityCoding/FizzBuzzEnterpris...