So I wrote an application that loads data from a 3rd party API. It allows the user to enter a record locator number and pull it up. By design, the value can be a partial match and it will pull up the record still.

The first API call I make only took 2-3 seconds, so I didn't see an issue as it's loading most of the data the app needs. I keep the filters/fields as they are and move on.

Fast forward 6 months. The user is complaining that the records are taking 30-45 seconds to load. Sure enough, load times are terrible. I've made lots of changes to what fields I'm loading through the API, and I'm calling several additional APIs, so I start pulling pieces of code out to see if anything improves. They all barely make any difference--still 30+ second load times. I end up removing everything except the first API call I developed that was taking 2-3 seconds before. Still taking 30+ seconds.

The 3rd party API allows you to filter using "starts with" or "contains". I used "contains" initially and had no issue, but I decided to try "starts with" since it should fit most use cases.

Load time is less than one second. I add back everything else. Load time is just over a second.

It seems that the 3rd party updated the API and multiplied load times by 10 when using that particular filter. I spent almost an hour on this since the platform doesn't support performance or debugging tools very well, and it all came down to a one line fix.