[VBprogrammer]

Optimising for simplicity first is almost always the right thing to do. Even if it turns out to be too slow you then have a reference implementation to confirm correctness against.

In my experience it's rare to correctly identify the bottleneck in code while writing it.

[bick_nyers]

Depends on your definition of simplicity.

Some view simplicity more as minimizing lines of code, e.g., less moving parts.

I view simplicity more as increasing lines of code, the goal being to make the code very verbose. Sometimes this means more moving parts, but smaller "movement" at each step.

There are other views of simplicity as well.

[Jensson]

> In my experience it's rare to correctly identify the bottleneck in code while writing it.

Why? It is so easy, just think of the work being done and pick the big parts, those are the bottlenecks.

Only reason I can see anyone fail at that is that they don't know how long things take in their programming language, but that takes very little time to learn, and once learned you will know the bottlenecks before writing.

In so many cases the bottleneck is using bad data structures everywhere, that often gets you 100x runtime and doesn't show up in a profiler because it is spread out all over the codebase, that is the real bottleneck that never gets fixed and is why programs are slow today. To fix that you have to learn to know the bottlenecks as you write the program and not rely on a profiler. Profilers helps you find how long things take, they are really bad at helping you understand how to make the program fast.

[eru]

Oh, I had situations in mind where I can quickly write a simple version.

But sometimes when I really torture my brain I can spend a few days of doing mathematical proofs etc to come up with a even simpler solution.

That extra effort is only sometimes necessary. (But can be lots of fun to develop.)