One of the nice features of IHP is that, thanks to Haskell’s strict type checking, it does not just eliminate bugs, it also speeds up development. E.g. if you want to change or build a new feature, you don’t need to write tests for it since the compiler basically does that for you. Since you don’t need to write tests, your work is perhaps half of what it would be normally – and neither do you have to know how to write good tests, which is an entire skill in itself.