Developing REST services and clients
Before the web and distributed systems that now permeate the cloud space, standards for communicating between systems were not in widespread use. This communication is often called an RPC. This simply means that a program on one machine has a method to call a function running on a different machine and receive any output.
Monolithic applications were the norm and servers tended to either be silo'd per application and vertically scaled or were run as jobs on larger, more specialized hardware from companies such as IBM, Sun, SGI, or Cray. When systems did need to communicate with each other, they tended to use their own custom wire formats, such as what you would see with Microsoft SQL Server.
With the web defining the internet of the 2000s, large monolithic systems could not provide the compute power behind services such as Google Search or Facebook at any reasonable cost point. To power these services, companies needed to treat large...