If you truly have "no room for error" (i.e. you are shipping code to a hundred-billion-dollar space vehicle), you might have:
- Very strict coding guidelines
- Rigorous code review
- An extremely thorough test suite
- Multi-stage approval through a QA process involving many pairs of eyes and thorough, formally defined and scientifically rigorous test procedures
- Static analysis and possibly even algorithms proved correct in Coq
Simply playing with it in staging for a while and determining that everything looks good is NOT the kind of testing that you do when there's "no room for error."
- Very strict coding guidelines
- Rigorous code review
- An extremely thorough test suite
- Multi-stage approval through a QA process involving many pairs of eyes and thorough, formally defined and scientifically rigorous test procedures
- Static analysis and possibly even algorithms proved correct in Coq
Simply playing with it in staging for a while and determining that everything looks good is NOT the kind of testing that you do when there's "no room for error."