So how did it go?
We expanded the test coverage, improved code testability by refactoring, and eliminated bugs introduced by code complexity. As a result, the number of bug reports to Rovio’s customer support was reduced to one third of the previous level. A quarter of the way through the project, Rovio’s own backend developer left the team, but they didn’t feel the need to hire a new one as they felt our developer was such a gem – so we became the team’s only backend developer. The number of players had been decreasing due to the bugs, but with our code clean up its now gone back up to over one million players a month. Rovio have been very happy with the results!