I was asked by a good friend on how to approach testing of a complex web application. How complex? Over 100 menu items, over 50 different screens, unknown amount of flows. He would be the only tester working in a small development team (10 developers). When he mentioned the lack of formal requirements, and explained why brainstorm sessions are not a real option I recognized how desperate situation he was in. He would be re-testing constantly! Like trying to shoot a moving target!