"Who is going to do it?" is always my first question whenever I am asked to estimate a piece of work. PMs/EMs are usually taken aback by the response, as if we are all supposed to pretend that all dev "resources" are equal. Yet reality doesn't fit into neat planning spreadsheets or burndown graphs, so often gets ignored.
I got a harsh lesson about this in one of my very first jobs. A senior engineer on my team had built a rather complicated system. He was accordingly intimately familiar with all aspects of it. So when he estimated something on that system, it came with nearly all the discovery work already done. The PM proceeded to take an estimate from this person, hand it to a brand new hire, and expect them to deliver on that. Nee…
When my product owner quit, the new guy was working in parallel for 2 months to learn the ropes, noboby bats an eye, but a programmer is productive from day zero and all programmers have exactly the same output. It's so wrong