To be reactive... or not to be

A long time has passed since single-threaded applications. Nowadays we have powerful production servers or even clusters with hundreds of CPU and terabytes of RAM, on top of it there are thousands of threads that processing clients' requests. But imagine the clients' throng in front of your gateway, and you pool and queue are full of incoming requests - what shall you do? How can we process the large number of requests and do not hang waiting for response of slow provider? So we will try to review basic strategies. Then, we will dive into RxJava and will try not to break it by our Observables. And lastly, i will try to drop a hint about next steps on the way to reactive microservices.