Go

Use pointer to slice or array, to avoid copying the value that is looped over, using & on range expression.

Multiple calls for append could be combined into a single call for append.

Using time.Tick in a way that will leak. Consider using time.NewTicker, and only use time.Tick in tests, commands and endless functions.

Sometimes reordering the operands can save computational resources because of the properties of operators like "&&" (AND) or "||" (OR) in a binary expression.

Compile parses a regular expression and returns, if successful, a Regexp object that can be used to match against text. When matching in a loop, use regexp.Compile instead.