I’ve made plenty of mistakes in the code powering WonderProxy, perhaps most famously equating 55 with ∞ for our higher-level accounts (issues with unsigned tinyint playing a close second). Something I think I got right though, was the concept of “managed accounts”. It’s a simple boolean flag on contracts, and when it’s set, the regular account de-activation code is skipped.

Having this flag allows us to handle a few things gracefully:

• Large value contracts
  By marking them as managed, they don’t expire because someone was on vacation when the account expired. They stay happy, the revenue continues, the expiry date remains accurate.
• Contracts with tricky billing processes
  The majority of our contracts pay us with PayPal or Stripe. A selection of contracts however have complex hoops involving anti-bribery policies, supplier agreements etc. This gives us some time to get this ironed out.
• Contracts where we’ve failed to bill well
  We occasionally make mistakes when billing our clients. When we’ve screwed up in the past, this helps ensure that there’s time for everything to resolve amicably.

This doesn’t mean the system has been without flaw. We currently get daily emails reporting on new signups, expired accounts, etc. It mentions all accounts that were not expired because of the managed flag.

Like most features, that was added after mistakes were made: we’d left some managed accounts unpaid for months. With better reporting, though, now, we couldn’t be happier with it.