Gotta love clients which ask you for a quote to expand the system you did for them, then a week or two later "accidentally" found some cheap absolutely garbage dev that made it for 1/5th of your price and during all that destroyed half your work, by e.g. replacing uuids with just ids, making the system now leak how many users there is, all their user saved content, allowing to just increment through them all, also then acting surprised when I decline any further work with them.

Then theres also clients that even after explaining all physical or software limitations, act like you should be a core developer and just fix that, for fucks sake you were using freaking excel sheets before, be happy with any possible change.