Literally painful dev learning experience: Do your damn stretches and invest in a good chair.

Spent a couple of months of WFH working eight hours a day in an awful chair and started getting back pain out of the blue. Part of my first paycheck after that went into a decent office chair, in hindsight I should've spent more on it but goddamn what a relief it was not having to spend an entire day in the tiny, back-breaking piece of shit my landlord calls a desk chair.