Simulating Сoncurrent Requests: How We Achieved High-Performance HTTP in PHP Without Threads

Manychat engineers tackled PHP's single-threaded HTTP bottleneck by creating an async worker pattern using Guzzle's concurrent capabilities. They serialize business logic and HTTP requests, hand them to async workers that leverage curl_multi_exec for simulated parallelism, then deserialize responses back to sync workers. This approach reduced 10k sync workers to just 300 async workers while maintaining existing PHP infrastructure.