FaaS

For all of the benefits that BaaS and SaaS provide, companies still have to incorporate bespoke feedback into products, and they often feel the need to retain control of some of the business logic that comprises the backend.

This control and flexibility doesn't have to be achieved at the cost of the benefits of BaaS, SaaS, and PaaS. Companies, having tasted the benefits of such big strides in infrastructure management don't want to add costs to managing and maintaining hardware, whether bare metal or in the cloud.

This is where a new paradigm, Function as a Service (FaaS), has evolved to fill the gap.

Function as a Service is a paradigm wherein a function is a computation unit and building block of backend services. Formally, a function is a computation that takes some input and produces some output. At times, it produces side effects and modifies state out of its memory, and at times, it doesn't.

What's true in both of the cases is that a function should be called, its temporal execution boundary should be defined (that is, it should run in a time-boxed manner), and it should produce output that is consumable by downstream components, or available for perusal at a later time.

If one was to architect their backend service code along these lines, they would end up with an ephemeral computational unit that gets called or triggered to do its job by an upstream stimulus, performs the computation/processing, and returns or stores the output. In all of this execution, one is not worried about the environment that the function runs in. All one needs, in such a scenario, is code (or a function) that is guaranteed to perform the desired calculation in a determined time.

The runtime for the code, the upstream stimulus, and the downstream chaining, should be taken care of by the entity that provides such an environment. Such an entity is called a serverless computing provider, and the paradigm is called Function as a Service, or Serverless Computing.

The advantages of such an architecture, along with the benefits of BaaS and SaaS, are as follows:

• Flexibility and control
• The ability to deliver the discrete and atomic components of the system
• Faster time to market