Having developed in Perl for many years, on a project that required fairly high performance, I learned that the key to getting good performance out of Perl code

Having developed in Perl for many years, on a project that required fairly high performance, I learned that the key to getting good performance out of Perl code is to use it idiomatically. Perl has a lot of built-in functions, keywords, and operators. It's also a bytecode-compiled language (yeah, Perl is compiled when you run it, the compiler is just so fast you don't notice it.) But a lot of those built-ins don't compile to the bytecode equivalent of machine code for a VM like you might expect; they compile to a single instruction that's got an optimized implementation written in C. When you write idiomatic code, you tend to use built-ins in a way that allows those optimized instructions to be used, which gives you near-C level performance. For example, if you want to loop over every member of a list, perform an operation on each member, and produce a new list based on the results of those operations, you could use a 'for' loop for that. But if you do than the Perl compiler needs to produce bytecode that mirrors the generic for loop and the full code in the body of the loop, pretty much as you wrote it. The compiler can't make any assumptions about the intended behavior. If you instead use the 'map' keyword, the compiler knows that you're transforming one list into another by running a bit of code on each member of the list, and it'll produce much more optimized code to do that. It's kind of ironic. You can write 'C' style code in Perl but you won't get C-like performance that way, you'll get Perl-like performance. But if you write 'Perl' style code instead, you'll get C-like performance.