[BurningFrog]

People don't like when I say this, but I think it's true:

If it typically takes you hours to "get inside" some code, that code is way too complicated.

[RussianCow]

Some problems are inherently difficult to understand, let alone solve. I'm inclined to believe that engineers at Meta solve a lot of these types of problems.

[BurningFrog]

You can solve difficult problems with simple, well factored code.

Just like your can solve simple problems with spaghetti code.

Of course, writing simple, will factored code is often hard!