Time from zero to being able to make a change and compile it would probably be the most objective metric I'd be looking at. I'd also be looking at density of i

Time from zero to being able to make a change and compile it would probably be the most objective metric I'd be looking at. I'd also be looking at density of interesting ideas(As per the "An engineer's job is to solve a problem with a minimum of new ideas" metric). If I see a lot of novelty then I would start questions whether the codebase was being treated like a sandbox to try out random stuff. Number of obsolete technologies used would be a big one. If there's 50 things about to be no longer supported, there's a maintenance nightmare waiting to happen. I'm assuming the black box behavior of both is truly identical in all cases, but in the real world it probably wouldn't be and edge case handling and unnecessary disk writes and such would be a high priority for me.