First, it's hard to come up with useful examples on command. :) Second, I was thinking more at the data persistence level. Which is harder to change than a sim

First, it's hard to come up with useful examples on command. :) Second, I was thinking more at the data persistence level. Which is harder to change than a simple refactor, and depending on the data store has zero cost (for example in MySQL booleans are just ints). They might then treat it as a boolean on the application side if there are indeed costs there. Either way, a Senior programmer has that conversation and recognizes the potential costs down the line. Then makes decisions about the tradeoffs.