Serverless vs function-as-a-service (FaaS) – let’s understand the difference




Wissen Team


May 28, 2024

The need for businesses to deliver digital solutions at scale and a pace never witnessed before is creating a challenging proposition for their existing technology ecosystem. While cloud computing and agile software development philosophies have created much more flexibility in the way applications are developed and deployed, there is still a long way to go for enterprises to achieve an end-to-end seamless experience with their digital channels. 

Instead of focusing on the core application functionality, most development teams are forced to spend a significant amount of time and effort on creating modular functional code and server management. However, there is a silver lining to this challenge today with the advent of serverless computing and Function-as-a-Service (FaaS) paradigms in application development.

In a broader sense, there are similarities between serverless and FaaS. They are both cloud-based backend alternatives for heavy-duty development activities. They both eliminate any need for server management responsibilities and enable users to focus solely on the application. But when we go deeper into its practical applications, there are several differences between the two. Before we explore the differences, it is important to first have a clear understanding of what serverless and FaaS mean in an enterprise application development ecosystem.

What is serverless computing?

Serverless computing refers to the approach of software development wherein all the configurations, management, and orchestration requirements of an application’s backend servers are handled by another provider thereby freeing development teams from intense activity. Serverless offers an alternative to building and maintaining a large plethora of backend requirements for applications such as databases, storage, DevOps pipelines, containers, etc. It creates a system where businesses need to focus only on the core application and not any associated backend configuration and resource management activities.

What is function-as-a-service or FAAS?

By definition, FaaS refers to the concept of creating functional logic on a cloud framework. Enterprise applications can leverage them as a service on demand. In a FaaS approach, the core application would communicate with a cloud vendor who hosts different functional modules that are either built by the vendor or created by the development team of the enterprise themselves and hosted on a cloud service provider. Either way, the functions are triggered when the application passes a call via a message or HTTPS request and is an event-driven computing architecture.

What are the key differences between serverless and FAAS?

Enterprises need to have a clear understanding of the differences between serverless and FaaS to ensure that they make use of the most suitable option in their application development strategies. 

Let us examine 4 key aspects that differentiate serverless and FaaS computing models:


In FaaS, development teams have more control over the deployment environment as they have the option to either customize a functional module offered by the cloud vendor or build their functional logic on the cloud with desired environmental and configuration credentials. This aids developer in having a better say in the technical environment that works best for their code. In the case of serverless, the entire backend server is handled by the cloud service vendor and developers only can configure the front-end logic of the application.

Cost and billing

Serverless computing is less complex when it comes to cost and utilization. Both, the vendor and the business, have a fixed range of computing infrastructure that is leveraged as a whole for creating the backend ecosystem of an application. Hence, it has a straightforward billing and pricing strategy. However, FaaS goes for a deeper and more complex web of utilization parameters that must be factored in while billing. A business may be billed for the number of instances of the function that is consumed by their application or on a flat fixed-fee basis for a bulk of instances or monthly usage patterns.


As with the cost and billing elements, scalability is an area where serverless has an advantage. It has a more defined and finite quantity of backend infrastructure that is to be associated with a particular application. Hence, it can scale automatically and without the need for any configuration changes from the vendor or the business. For FaaS, there will be multiple functional units that may be leveraged by a business’s application ecosystem at a given point in time. The scalability requirements also vary as different components of the application may require one or more specific functions to scale while the other functions remain neutral. This also creates the need for more flexibility in configurations from the vendor side.

Tools and platforms

FaaS offers a wide range of tools and platforms that development teams can leverage to manage the backend functions needed for their core applications. With serverless computing, there isn’t much of a control panel that developers have since most of the backend infrastructure is available as a single consumable service from the cloud vendor. However, serverless will enjoy the benefit of lower managerial overhead.

Serverless and FaaS have a lot in common and can both be leveraged to propel enterprise technology development initiatives to their next level. Businesses need to have the right guidance and strategic approach in selecting either or both on a case-by-case basis. It is where our consultants can help set you on the right trajectory.