Client said: "And you promise there won't be any caterpillars in the app...",I gave him a strange look, he continued: "or how do you call that mistakes in apps".

He meant bugs...

I you find caterpillars it's time for new infrastructure.

No. I promise I'll try to reproduce bugs that you report. If I can, I promise to not make fun of you on the bug report you filed. If I can figure out the underlying issue, I promise I'll try to solve it without breaking any of the other working features. If I can do all that.. Well, still no. I promise that there will be some weird edge case that no one thought of, so there will always be bugs somewhere.

So, no. I can promise I won't lie to you about the product that we're making together, though.

ladybugs...