The NFR’s and technical requirements should be part of the user story. These can be added as constraints to the story or along with the definition of “done”. Most of these NFR’s can be tested with unit test framework or automated test scripts. Sometimes the process cannot be tested directly. Suppose software requires triple encryption of bank transactions or such things then it will be very difficult to check the state in between. You will have to test the results to verify the process. The ticket generation or the account balance after the transaction will give a correct picture. Performance testing can be integrated with Continuous integrations build or nightly builds.