Let’s Encrypt helps to protect a huge portion of the Web by providing TLS certificates to more than 235 million websites. A database is at the heart of how Let’s Encrypt manages certificate issuance. If this database isn’t performing well enough, it can cause API errors and timeouts for our subscribers. Database performance is the single most critical factor in our ability to scale while meeting service level objectives. In late 2020, we upgraded our database servers and we’ve been very happy with the results.