Collin O' Dell, member of the PHP League, shares how he was able to significantly improve the performance his json5 package using Blackfire profiling.

Back in November I released colinodell/json5 - a JSON5 parser for PHP. It's essentially a drop-in replacement for PHP's json_decode() function, but it allows things like comments, trailing commas, and more.

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I always knew that a PHP-based implementation would be slower than PHP's native C implementation, but execution time measured in minutes was completely unacceptable!

So I fired up Blackfire (which I've previously used to optimize league/commonmark) and got to work.

https://www.colinodell.com/blog/201801/optimizing-colinodelljson5-blackfire