Member-only story
I Added @Async to Make My Spring Boot API Faster. It Got Worse.
Everything looked faster in testing. Then production traffic arrived.
The API was slow, so I decided to move one of the expensive operations into the background using @Async. The response time immediately looked better, and honestly, it felt like I had fixed the problem.
But a few hours later, production started behaving differently. The API was still responding quickly, yet background tasks were piling up and other parts of the system were becoming slower.
That’s when I realized something important:
Making an operation asynchronous doesn’t make the work disappear.
It simply changes where and how the work waits to be completed.
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Now, let’s get into the article.
The Endpoint Looked — Completely Normal
Imagine we have a simple order API. After creating an order, the application needs to send an email, update analytics, and create an audit record.
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