MySQL

MySQL is the relational database that powered the early internet and never really left. It’s the “M” in the classic LAMP stack, and it’s been quietly sitting behind WordPress sites, e-commerce platforms, and countless web applications since 1995. Acquired by Sun, then absorbed by Oracle, and forked into MariaDB by its original creator — MySQL has had more drama than a startup board meeting, yet it keeps on serving queries.

What makes MySQL so popular is its approachability. It’s fast for read-heavy workloads, relatively easy to set up, and has documentation older than some junior developers. Its InnoDB storage engine handles transactions and foreign keys like a proper relational database should, while its replication features let you scale reads across replicas. Sure, PostgreSQL fans will tell you their database is more feature-rich (and they’re not wrong), but MySQL’s simplicity is a feature, not a bug.

Why it matters: MySQL remains one of the most deployed databases on the planet. Understanding it is practically a rite of passage for backend developers, and its ecosystem of tools, hosting options, and community support means you’re never far from a solution when things go sideways.