Few things are scarier than a database slowly losing integrity over weeks or years. For a while, nobody notices anything. Then users start reporting bugs, yet you can't find any code that's broken. By the time you realize the problem, it may be happening for so long that your backups are unusable. We can avoid problems like these with skillful use of transactions.

Few things are more frustrating than slow, flaky test suites. You're ready to deploy, wait 20 minutes for CI to run, only to find that a test failure in code you've never touched is blocking you. You dig into the source and find the problem: an external API call. It works (slowly) most of the time. But sometimes the network glitches and it fails. What do you do? In this article, José Manuel shows us several techniques for removing external API dependencies from our tests.