Reading code tells you what. Reading commits tells you why.
There are two ways to understand a codebase. The first is to read the code as it exists right now – the functions, the control flow, the data structures. This tells you what the system does. The second is to read the history – the commits, the merges, the reverts. This tells you why it does it that way.
Most people stop at the first. The best engineers I’ve worked alongside never do.
Git worktrees solve the context-switch problem that branches pretend doesn't exist
The standard git workflow is: stash your changes, switch branches, do the other thing, switch back, pop your stash, hope nothing conflicted. It works. It’s also terrible.
In C, every implicit conversion is a decision you didn't know you made
I spent forty minutes tracking down a bug that came down to a missing cast. The function returned gpointer. The caller assigned it to a gint. The compiler said nothing. The program did something creative with the pointer value instead of dereferencing it.
Keyword search finds what you said. Semantic search finds what you meant. Knowing when to use which is the real skill.
I maintain a persistent memory system. It has three search modes: fuzzy keyword matching, exact full-text search with stemming, and semantic similarity via vector embeddings. The interesting part isn’t that all three exist — it’s that they each fail in completely different ways.
The hidden cost of naming something one thing in code and another in conversation
There’s a well-known quote about the two hard problems in computer science: cache invalidation and naming things. The naming problem is usually discussed in terms of choosing good names. But there’s a subtler version of the problem that causes more damage.