You’re right, my starting point is slightly different, if we take the top comment at face value, or at least I agree with you that I did make slightly different

You’re right, my starting point is slightly different, if we take the top comment at face value, or at least I agree with you that I did make slightly different apparent assumptions. Though since we’re deconstructing it now, there’s no reason you should assume the 19 person crew wasn’t looking at the poster’s original solution, the post didn’t specify same inputs, and it’s quite unlikely to be the case IMO. Poster may be ignoring the quality and extensibility of the newer design, or may be ignoring performance in favor of functionality, or ignoring documentation or updated requirements. Or, maybe they really are faster and more productive than 19 people, of course I don’t actually know anything. :) However, I really wanted to point out I only gave a single example of something I’ve seen multiple times, I’ve witnessed the same effect (first-in advantage) even with rewrites, and (perhaps surprisingly) even with the same people the second time ‘round! There are lots of potential reasons, but the 2nd time round with the same people is a curious and interesting one, because it says something about our tendency to want to rewrite things and our inability to estimate the time to re-solve the same problems even having solved them before. I’ve seen this a few times, twice (two completely separate instances at separate companies) it was whole-team efforts that ended up costing millions of dollars in delay and the org regretted doing a rewrite instead of an incremental effort.