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Slow database queries are really a pain. It’s easy to blame Django for taking ages to process a request, but the real issue may lie in an SQL query not doing what it should be. These performance degrading queries are often hiding in plain sight. By the time you notice them, they are already affecting your end users. AppSignal is an application performance monitoring (APM) tool with support for Python and Django out of the box.

For years, Angular lived with a subtle contradiction. The framework steadily modernized its reactivity model with signals, fine-grained change detection, and a clearer mental model for component state. Yet forms - arguably one of the most important parts of most applications - continued operating under an older, push-based system built around events and subscriptions. Developers felt this split immediately.

Whenever you place an order on Amazon (or any other e-commerce site for that matter), you get that “order placed successfully” notification almost instantly. But did you know that there’s much more to the whole experience than meets the eye? In Python applications, Celery is the major driver behind the whole thing. The tasks that take time are queued and sent to brokers.

Slow Express routes rarely look broken in logs. They just feel sluggish to users. With AppSignal, though, you can quickly identify which endpoints are the slowest, gain insight into each request, and find out if the latency is related to any errors or slow queries. In this guide, you'll set up a mock Express application, create a load, and use AppSignal to analyze a route's performance as if you were working through a live incident.

A sports car can only be driven as fast as the road it's driven on. If you're stuck behind a tractor on a single-lane road, you're not going anywhere fast. The same idea applies to web performance: your application's throughput is only as fast as it's slowest bottleneck. For Phoenix applications, that bottleneck is almost always the database.