Definition
Constraint management is the discipline of working out which limits on a problem are real and which are merely assumed, then solving the problem within only the genuine ones. Real constraints are immovable boundaries. Imagined constraints are habits, conventions, or unexamined beliefs that feel binding but are not.
The Pragmatic Programmer authors illustrate this with puzzles whose difficulty disappears once you notice you have imposed a rule the problem never stated. The same trap appears constantly in engineering.
Why it matters
How it works
When a problem feels intractable, write down every constraint you believe applies, then challenge each one with a simple question: is this truly required, and who or what requires it. Often a constraint dissolves on inspection, opening solutions that were previously invisible.
For the constraints that survive scrutiny, treat them as design inputs. A genuine performance budget, a fixed protocol, or a legal requirement narrows the design space, and a narrower space is easier to search. The skill is neither ignoring constraints nor obeying them blindly, but knowing which is which.