1. Simplicity
2. Clarity
3. Generality
-- Brian W. Kernighan, Rob Pike

I frequently use the following paradigms and techniques:

• OOP - Well, who doesn't? I've been teaching object-oriented programming and object-oriented analysis and design (OOA&D) as part of my InstructorRole, although I've never been a true believer in the pure-OOP dogma. OOP has very broad applicability in many areas of CS, and that's all.

• Metaprogramming — I've been in love with templates of templates for a while. Oh, yes... I must admit this little perversion of mine. In the past, you couldn't abuse genericity because your buggy compiler would blow up. Now that compilers have been fixed, your mind melts first.

  This is a little useless thing that not even Boost would ever want to carry around:

  viterator

• Functional Programming — I'm ashamed to admit I never tried a purely functional approach in a real-world project, but I do frequently use "pills" of functional programming, expecially in combination with the StandardTemplateLibrary and with Perl.

• Design Patterns — Like many, I know, use and teach the good old GangOfFour patterns and sometimes the more esoteric ones. Actually, I mentioned them only to say that I dislike both code that reinvents them as much as code that abuses them (the SingletonPattern and AbstractFactoryPattern are expecially popular with novices).

• Multithreading — I tend to use it as a last resort solution in my designs, because I consider truly concurrent programming extremely hard to understand, debug and extend. Most of my multithreading programming was on the AmigaComputer (whose multitasking OS lacked memory protection and was thus a hell of a multithreading environment) and on Windows (where multithreading is popular because of the limitations and inefficiencies of the IPC primitives and the broken asynchronous I/O).

• Compiler design — I'm experienced in writing grammars and hand-writing the lexical analyzers and parsers as well as using the usuals automated tools. I understand problems related to AST representation, optimizers, and code generators. See OpenSourceDeveloperRole for GCC contributions.

• Kernel development — I'm particularily interested in OS design. I wrote lots of system-level code and utilities, including a microkernel called BeRTOS.

And, of course...

• Spaghetti programming!