You may be using asynchronous processing with one of the messaging platforms like RabbitMQ, SQS, Beanstalkd, etc already. Or you may be using one of the frameworks (Ecotone, Symfony Messenger or Laravel Queues) to hide messaging platform details. No matter what you use, sooner or later you will face errors
Message processing becoming more and more popular in PHP. Putting all the logic inside simple Request - Response model becomes not enough for our current system needs. Our applications do more and more. It becomes standard to send an email after registration, call external Services or perform some intensive tasks.