Eh, yeah. Once had a service provider promise their new API would “easily” (I still remember the tone the sales rep used every time he said easily; must have practiced it came out sounding the same every time).

3 months of integration dev later, we start load testing, the external API fails spectacularly. They tell us to redesign to use their old batch API 35 days before our deadline. We tried, failed, ate shit with our customers. Provider was too big to pick a fight with. Startup failed.

Welcome to software engineering.