Q: Should I run synthetic checks or real-user monitoring? How do I set up both?

Q: Should I run synthetic checks or real-user monitoring? How do I set up both?

A: They answer different questions, so run both in this split.

— Synthetic (a robot hitting your site on a schedule): use it for 24/7 uptime, SSL, and critical-path checks like login and checkout. It works even at 3am with zero traffic.
— Real-user monitoring (RUM, a script in real browsers): use it for actual load times, broken assets, and JS errors your users hit that a robot never would.

Setup order: synthetic first (it's your alerting backbone), RUM second (it's your context). Wire synthetic to paging. Wire RUM to dashboards, not pages.

The follow-up: synthetic tells you "checkout is down," RUM tells you "checkout is slow only for mobile Safari users." You need both stories.

Got a question? Drop it in the comments.