The only way to write complex software that won't fall on its face is to hold its global complexity down - to build it out of simple pieces connected by well-defined interfaces, so that most problems are local and you can have some hope of fixing or optimizing a part without breaking the whole

Lisp is worth learning for the profound enlightenment experience you will have when you finally get it; that experience will make you a better programmer for the rest of your days, even if you never actually use Lisp itself a lot.

Given enough eyeballs, all bugs are shallow (e.g., given a large enough beta-tester and co-developer base, almost every problem will be characterized quickly and the fix obvious to someone).

Ugly programs are like ugly suspension bridges: they're much more liable to collapse than pretty ones, because the way humans (especially engineer-humans) perceive beauty is intimately related to our ability to process and understand complexity. A language that makes it hard to write elegant code makes it hard to write good code.

A software system is transparent when you can look at it and immediately see what is going on. It is simple when what is going on is uncomplicated enough for a human brain to reason about all the potential cases without strain

Rushing to optimize before the bottlenecks are known may be the only error to have ruined more designs than feature creep. From tortured code to incomprehensible data layouts, the results of obsessing about speed or memory or disk usage at the expense of transparency and simplicity are everywhere. They spawn innumerable bugs and cost millions of man-hours - often, just to get marginal gains in the use of some resource much less expensive than debugging time

When writing gateway software of any kind, take pains to disturb the data stream as little as possible - and never throw away information unless the recipient forces you to!