Today we were fixing some old unit tests for our large marketplace software, when I stumbled upon a peculiar test case. The test, written in 2005 assumed that a suitable date far in the Future would be 2015-01-01, and was now failing.
Anyway, the morale of the story is that at least at PHZ.fi, where we endeavor to build Sustainable Software, let’s expect that our software will be used for more than 10 years, before somebody rewrites it! In our case we are still using more than 10 year old software, but since we have unit tests (that now pass 100% again), it can still produce (a lot) business value. For a developer building sustainable software over building low quality, throw-away software, makes a big difference on the impact you contribute to the world.