After 20 years in the same company, I learned I always end up needing it. Someone is always going to show up with some harebrained custom request 3 days after we go live. I’ve started assuming this from the start and it’s saved me countless headaches. The cost of building the flexible in from the start is minimal compared to the cost of trying to do it later.

Other companies may have different cultures around this stuff, but when the culture seems to demand it, it’s easier to just plan for it.