It's not hard to do what they did, so I'm not surprised they did it themselves. It's just simple async queue processing, and doesn't really need a lot of sophis

It's not hard to do what they did, so I'm not surprised they did it themselves. It's just simple async queue processing, and doesn't really need a lot of sophistication, especially at just 1M notifications per hour. Now if they need to process a few orders of magnitude more, then AWS SNS would probably be a good next step.