During the beta for a product, we were working on sending out daily summary emails to our users. We had a cron job which should run at 8:00 AM in the morning wh

During the beta for a product, we were working on sending out daily summary emails to our users. We had a cron job which should run at 8:00 AM in the morning which would process the queue and summarize all activities into a single email. It being a very long day, I deployed the job with the cron expression * 8 * * * instead of 0 8 * * * , which meant it ran EVERY minute starting at 8:00 AM instead of just once. The next morning I woke up to a flurry of text and emails saying customers had complained they received emails about a hundred times. Thankfully, we had a pause in the job which meant it went out only a hundred times and not thousands as one would have expected!