So I had been developing a real estate website and developing a MLS feed parser. I had only 1 year experience at that time and parsing a XML feed was already complex enough. On top of it, the client wanted to automate feed download from the MLS provider through HTTP authentication. Managed to do it. Everything worked for 15 days and on 16th day the property location markers stopped appearing on Google maps. Turned out that address to lat-long reverse geocoding was failing because API limit exhausted. My bad, I coded it on view instead of caching the lat-long in database. Fixed it in a day and viola!