i_am_a_cardboard_boxProgramming exercise during job interview
You essentially have to practice for them by solving a whole lot of them.
That is part of it, but you also need to practice asking clarifying questions and collaborating around a solution. OP was pretty much guaranteed to fuck up their first go. It’s something that gets easier over time.
Also, something that really messed me around was that System Design questions have a particular form and expectations around them. So read up on how they flow and practice those too
About the “guaranteed to fuck up on the first go”, I got strongly encouraged to first apply to positions I wouldn’t love (but was okay with), just to learn the ropes of interviewing. Once you have done one or two, time to shoot for your dream job!