[LouisSayers]

It's not something that happens very often, so I'm OK with pushing myself a bit before interviews.

The way that I see it is that it's a financial investment. Not only can you increase your chances of multiple offers (which can lead to increased salary), but performing well could be the difference of $10k+ salary per year.

If you think of raises as a percentage of salary and compound that over the years you might spend at a company, then potentially we're talking multiple 10's of thousands over the lifespan of working at a company - all for a bit of extra effort up front.

It is extra strain for sure - the smart thing to do is to start your prep a month or more before applying. Also, don't keep your prep code in the IDE. I did this (had an 'archive' folder), and Intellisense was picking up the name of an existing class I'd used during my practice (not sure if the interviewer noticed that...)!