Cloud costs
June 16, 2023
min read

What is serverless?


In today's digital age, serverless computing has emerged as a transformative force in the software development landscape. As the industry continuously seeks to optimize for efficiency, scalability, and speed, serverless computing is becoming the preferred choice for many businesses, and it’s transforming how businesses deploy and run their applications. This comprehensive guide will demystify serverless computing, explore its advantages,  illuminating why it's a game-changer for modern application development.

The Journey to Serverless

In the world of software development, we've seen a significant evolution in how we design and build applications. This journey has taken us from monolithic architectures to services and now to functions. Traditional monolithic applications, where all functions are tightly interwoven and managed in a single unit, were the norm. However, these applications posed challenges in scalability and continuous delivery, making it difficult to update or scale just one part of the application. To address these issues, the industry began transitioning towards Service-Oriented Architecture (SOA). Here, applications were structured as a collection of loosely coupled services, each fulfilling a specific business purpose and capable of being developed and deployed independently. This offered more flexibility and efficiency compared to the monolithic design. 

Microservices architecture further refined SOA, breaking down applications into even smaller, independent services. Today, we've entered the era of serverless computing and Functions as a Service (FaaS). In this model, applications are segmented even further into individual functions, each capable of being developed, deployed, and scaled independently. Serverless computing enables developers to focus on the business logic in their code, without worrying about the underlying infrastructure, server management, or scaling. This progression from monoliths to services to functions represents our ongoing quest for greater modularity, scalability, and productivity in software development.

What is Serverless Computing?

Serverless computing, despite its name, does not imply a world without servers. Instead, it represents a model where developers can build and run applications without having to manage servers themselves, shifting the responsibility of managing servers to cloud providers, freeing up more of their time to writing applications.

Typically, serverless computing services are categorized into two main types: Backend-as-a-Service (BaaS) and Function-as-a-Service (FaaS):

  • Backend-as-a-Service (BaaS) involves third-party services providing ready-to-use backend functionality. Examples of BaaS include Google Cloud Storage (GCP) and Amazon's S3 for storage, or database-as-a-service offerings such as Google Cloud Firestore and AWS DynamoDB. These services allow developers to leverage existing backend services without having to create and manage their own.
  • Function-as-a-Service (FaaS), on the other hand, allows developers to execute small units of code (or functions) in response to events, without having to worry about the underlying infrastructure. Examples of FaaS include AWS Lambda, Google Cloud Functions, and Microsoft Azure Functions.

How Does Serverless Work?

The magic of serverless computing lies in the concept of Functions as a Service (FaaS). With FaaS, developers can execute backend code by running individual functions - small units of code, each performing a specific task. These functions are stateless and execute in response to events, such as HTTP requests, database operations, or in-app activity. When an event is triggered, the cloud provider runs the function, allocates the necessary resources, and then de-allocates them when the function completes .

Key Attributes of Serverless Computing

No Server Management: The most defining characteristic of serverless computing is that developers do not need to be concerned about server provisioning or maintenance. This is all handled by the service provider.

Cost Based on Consumption: Serverless computing follows a pay-as-you-go model. You only pay for the compute time you consume. When your functions are not running, you don't pay anything. This can be more cost-effective than traditional server-based hosting where you pay for server capacity 24x7 whether you use it or not.

Microservices and Decoupling: Serverless promotes the use of microservices by allowing developers to deploy functions independently of each other. This decoupling of services can make applications more modular, easier to maintain, and faster to update.

Event-Driven Programming: Serverless is inherently event-driven. Functions are executed in response to triggers or 'events', which can come from a variety of sources, like a user clicking a button on a website, a new file uploaded in a storage bucket, or a new record in a database. This paradigm supports efficient, real-time processing and can lead to more responsive and dynamic applications.

Short Execution Durations: Functions in serverless architectures are designed to run for a short period of time. Long-running functions could lead to higher costs and are generally discouraged in a serverless architecture.

Statelessness: Each function call in serverless computing is independent. They do not store any data between calls. If data needs to be persistent, it should be stored in a database or some other kind of external storage system.

Why Businesses Are Embracing Serverless Computing

Focus on Code, Not Infrastructure: With serverless computing, developers can focus on writing and maintaining code, not managing and scaling servers. This shift can lead to faster development cycles and faster time-to-market for new features and applications.

Faster Time to Market & Increased Productivity: Serverless computing allows developers to get their applications to market faster. Since they're not managing servers, developers can focus on business logic and features, reducing the time it takes to release new software. Moreover, deploying is easier compared to traditional apps, enabling developers to be agile and innovate. 

Cost Efficiency: In serverless models, you pay only for the compute time you consume. There's no need to pay for idle server time, which can lead to significant cost savings, especially for applications with variable traffic patterns.

Automatic Scaling: Serverless architectures can automatically scale to meet the demands of your application. Whether you're handling a handful of requests or a sudden surge of thousands, serverless architecture can accommodate the load without manual intervention.

High Availability: Serverless platforms automatically provide built-in availability and fault tolerance. You don't need to architect for these capabilities since the services running the application provide them by default.


In conclusion, serverless computing offers a new paradigm for application development and deployment, enabling businesses to innovate faster, scale more efficiently, and reduce costs. As we continue to witness the proliferation of serverless architecture, it's clear that this approach is not just the future of software development - it's the present.

To learn more about serverless deployments with Harness please visit AWS Lambda deployments tutorial , or request a demo .

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