If your company has design documents that describe not only how systems have been designed, but also _why_ they've been designed that way, then you can: 1. Rea

If your company has design documents that describe not only how systems have been designed, but also _why_ they've been designed that way, then you can: 1. Read the problem statement (or context, or motivation) in a particular system's design doc. 2. Flip through DDIA (the book others mentioned) to find relevant material, and try to decide how you would solve the problem. 3. Go back to the design doc and see what your colleagues decided. By trying to solve problems yourself, and seeing what colleagues did in the same situation, you will learn to improve your thinking. The good thing about doing this within your existing environment is that you can ask colleagues when you don't understand "why didn't we just use X for this system?".