I wish it was interesting, or even sane... one day my website got like a million more users /that day/ and every database mechanism I had to do some of the user statistics I was keeping totally failed: the website ground to a halt. So, rather than decide what I really wanted to keep, I frantically developed a little library that stored all of that data into S3 as a giant key/value store, with my own little makeshift inverted indexes. Needless to say, this was stupid, and when I next checked my S3 bills I noticed I was doing a billion puts per month (which costs like $10,000). Lukily, this has only been a few months, and I'm now fixing the situation during a giant cost-cotti g endeavor... but yeah: omg that was stupid.

(typed on my iPhone and therefore a little shortened: hacker news comments suck on the iPhone)