Only had to do it a few times, but exactly my experience. The main one was spending ~3 months and speaking to ~40 people in order to write 2 rest APIs in about

Only had to do it a few times, but exactly my experience. The main one was spending ~3 months and speaking to ~40 people in order to write 2 rest APIs in about 300 python LoC. It was a minor integration between 4 different services owned by different groups, with no one knowing anything about any system/functionality outside a very small slice of the domain they controlled. At best they could point me to another person to ask, with every question taking a minimum of three levels of indirection to resolve. They were fully aware of the situation too; utterly shocked we managed to close it out in those 3 months. They had more than enough software developers and knowledge to do it themselves — my only value add was piercing the veil, navigating through all their compartmentalized knowledge to get a straight answer