What we check first when a site gets slow
When a client tells us their site got slow, we resist the urge to start tuning. Most slowdowns have one cause, and these five checks usually find it within the first hour.
The checks
- Did anything change? Deploys, plugin updates, a new marketing script, a traffic spike from a newsletter.
- Is the server short on something? Disk space, memory, open connections, CPU steal on a shared host.
- Which requests are slow? The slowest ten endpoints by total time, not by average.
- What does the database say? The slow query log almost always names the culprit.
- Is it the network? A slow third-party API or DNS lookup can look exactly like a slow server.
Only after these do we look at caching and configuration. Tuning a system before you know what is wrong usually moves the problem somewhere harder to see.