What could be the reason that my site has poor performance?
When Oh Dear reports poor performance, the slowdown is almost always in one of these places:
- Application code: slow routes, heavy controllers, N+1 query problems, or unoptimized views
- Database: missing indexes, slow queries, or a database server that's running hot
- Caching: a warm cache quietly going cold, or cache keys being invalidated more aggressively than intended
- External dependencies: APIs, payment providers, or auth services responding slowly
- Server health: CPU pegged, disk or memory pressure, a garbage collector running long
- Network and routing: new firewall or WAF rules, dropped packets forcing TCP/TLS to retransmit, or upstream provider issues
Why not the network itself? Because network transfer is almost always the fastest part of a request. Most time is spent setting up the connection (TCP, TLS handshake) and waiting for the server to do its work. So if Oh Dear reports sluggish checks, the server side is where to look first.
It's also worth ruling out the outside world. Large-scale outages at hosting providers, CDNs, or DNS resolvers regularly affect specific regions without any change on your side.
Oh Dear lets you pick the primary location for each uptime check and always verifies problems from a secondary location, so you can quickly tell a region-specific issue from a site-wide one.
Want to dig deeper? Daily Lighthouse audits give you a breakdown of rendering performance, and the performance check can alert you when response times drift from their recent baseline, not just when they cross a hard threshold.
