Comment by tlarkworthy

5 days to fix a bug! Jesus, write better code, write tests, with good logging. Break your code apart into testable modules. Test you hypothesis from he ground up. If you can't localise the bug quickly there is something wrong with your methodology. You need to use a debugger. Clearly you are trying to debug a house built on sand. I find this is a common problem. People don't realise 80% of your time is spent debugging and checking your assumptions. If you are writing reams of code before checking your assumptions than you pay quadruple cost. The first thing I do when building a big data processing project is think about how I am gonna debug it first. Invest tons of time at the beginning getting readable output in a console. I have gone as far in some projects to output trees and grids in ASCII art to visualise data structures (in the console). I have never spent 5 days debugging a bug since university. The days spend at the beginning of the project making the debug output as good as possible pay for themselves a hundred times over.