What Is Serverless Computing? {Serverless Model Explained}

Serverless computing is redefining how businesses and developers approach software development and deployment. By eliminating the need for traditional server management, serverless computing allows developers to focus on writing code and build better products in a scalable, flexible, and cost-effective environment.

This article explains everything you need to know about serverless computing, its benefits and challenges, and scenarios where it assists businesses in software and application development.

What Is Serverless Computing?

Serverless computing is a cloud computing model where a cloud provider manages the allocation and provisioning of servers, allowing developers to focus on building and running code without the hassle of managing servers. With serverless computing, developers purchase backend services from the vendor, who is responsible for infrastructure management and maintenance, updating, patching, system monitoring, and security.

In the serverless computing model, applications are broken down into individual functions that run in response to events such as HTTP requests, database operations, or queue processing. This event-driven architecture allows developers to only pay for the resources utilized during the execution of functions.

Serverless computing is suitable for a wide range of applications, from simple web apps to complex data processing systems. This computing model allows developers to offload server management and infrastructure to the cloud provider. As a result, it speeds up the deployment cycle as resources are automatically scaled to match the demands of the application without the need for manual intervention.

Serverless Computing Elements

Several key elements encompass serverless computing, including specific technologies, tools, and services. The components that make up the serverless paradigm are the following:

• Function as a Service (FaaS). FaaS takes on the maintenance and management of the underlying infrastructure, so developers can focus solely on coding without worrying about the server needed to run them.
• Event-driven architecture. In the serverless computing architecture, applications are designed to respond to various triggers or events, like user actions, database changes, or IoT signals.
• Automatic scaling. Serverless platforms automatically scale resources up or down based on demand to prevent over or underutilization.
• Built-in availability and fault tolerance. Serverless platforms are designed to easily handle failures and ensure applications are available without the developer having to step in.
• No server management. In serverless computing, the cloud provider is responsible for management and maintenance, so developers can focus solely on writing and executing code.
• Pay-per-use pricing model. Serverless costs are based on the resources executed functions consume, providing cost-efficiency.
• Statelessness. Serverless functions do not retain any internal state between executions, simplifying scalability and management.
• Integrated development and deployment. Serverless platforms provide services for continuous integration and development (CI/CD), streamlining development, testing, and deployment processes.
• Ecosystem and community. The serverless ecosystem is vast, with a wide range of tools and frameworks that support various aspects of the development and deployment of applications.

Serverless Architecture Explained

Serverless computing architecture refers to certain design principles that impact how applications are built, deployed, and managed in a serverless environment. It is based on the following principles:

• Decomposition into functions that perform specific tasks.
• Event-driven design that structures applications to execute functions in response to events.
• Managed services integration with databases, authentication, and other backend functionalities, removing the need for traditional server management.
• Stateless and ephemeral execution ensures that functions only exist for the duration of their execution.
• API gateway integration that exposes serverless functions to external applications and services.

Benefits of Serverless Computing

Serverless computing offers developers and organizations many benefits:

• Cost-effectiveness. In a serverless computing model, organizations only pay for resources they use, thanks to the pay-per-use model. Since the cloud provider handles the infrastructure, server maintenance overhead costs are significantly reduced.
• Scalability. This model is highly scalable, efficiently handling variable workloads and increases in traffic.  
• Operational efficiency. Since developers only focus on writing the code, this accelerates the development lifecycle and results in resources being spent on innovation and development of core product features.
• Flexibility and agility. Deploying functions is easy and cheap, so testing is much simpler, especially when it comes to small, independent services.
• Microservices-friendly. A serverless environment allows for the deployment of small, self-contained services that can be scaled and updated independently, aligning well with microservices architecture.
• Reliability and resilience. Serverless platforms are highly redundant and resilient against failures, and providers automatically handle failover and recovery processes.
• Enhanced security. The cloud providers guarantee the security of their infrastructure. And since there is no persistent server or infrastructure, the attack surface is significantly reduced.
• Community and vendor support. The serverless environment is supported by a variety of frameworks, tools, and extensive documentation that enables implementation.

Drawbacks of Serverless Computing

On the other hand, there are some drawbacks to serverless computing that organizations should consider.

• Cold starts. This happens when a serverless function is invoked after a period of inactivity, resulting in a delay and higher latency, which may affect performance-sensitive applications.
• Vendor lock-in. Serverless architectures are specific to cloud providers, so switching vendors can be challenging.
• Limited customization and control. Since the cloud provider manages the serverless environment, customization and control options are limited.
• Monitoring and debugging complexity. The monitoring and debugging of applications is complex in a serverless environment due to the difficulty of identifying issues across multiple functions and services.
• Data management. Data management is challenging since serverless functions are stateless and do not retain data between executions.
• Security concerns. Security in serverless computing is based on the shared responsibility model, requiring developers to do their part in protecting data and operations and maintaining compliance in the serverless environment.
• Performance limitations. Serverless platforms sometimes impose limits on resources such as execution time, memory, or concurrent executions, affecting performance.
• Cost predictability. As costs are based purely on usage, it may be difficult to predict costs, especially for applications with highly variable workloads.
• Testing and development environment. It is challenging to replicate the serverless environment locally for development and testing purposes, possibly leading to the “works on my machine” problem.
• Network latency in integrations. Network latency often happens when serverless functions interact with other services and APIs, affecting the response time of applications.

Serverless Computing Use Cases

There are many use cases that serverless computing makes more efficient. They include:

• Web applications. This is a prime use case of serverless computing since serverless platforms efficiently handle varying workloads without disrupting the traffic.
• APIs and microservices. As each RESTful API or microservice represents a different endpoint, serverless environments are ideal for their development and deployment.
• Event-driven data processing. Serverless functions process data in response to events, saving time and resources.
• Real-time file and stream processing. Since serverless functions process data as they arrive, this is an ideal scenario for real-time processing.
• Scheduled tasks. Serverless makes running scheduled tasks such as nightly database backups, periodic data cleansing, and batch processing easier and cheaper as it removes the need for dedicated servers.
• IoT applications. Internet of Things (IoT) applications often involve processing data from numerous devices, and serverless functions respond to IoT-triggered events smoothly.
• Mobile backends. Serverless computing provides an easy-to-manage backend solution for mobile applications and functions such as user authentication, data storage, and push notifications.
• Chatbots and virtual assistants. Serverless functions power chatbots and virtual assistants by responding to user inputs with minimal latency.
• Machine learning and AI. Serverless architecture is cost-effective and suitable for on-demand machine learning and cloud-based AI services.
• Ecommerce websites. Serverless architecture is suitable for building ecommerce platforms, inventory management, order processing, and payment transactions.

Serverless Computing vs. Other Models

Here is how serverless computing compares to other computing models.

Serverless Computing vs. Backend-as-a-Service

Both serverless computing and Backend-as-a-Service (BaaS) simplify web and application development by abstracting the server infrastructure. However, their main difference is in their approach and flexibility.

Serverless computing focuses on running backend code without managing servers, which is the responsibility of the cloud provider. With this model, developers focus on writing code while the provider allocates resources as necessary. Serverless offers granular control and is suited for applications requiring custom backend logic with variable demands.

On the other hand, BaaS offers a more comprehensive set of features, such as databases, authentication, cloud storage, and push notifications. This makes it popular with mobile developers who want to build applications quickly without worrying about the infrastructure or the code. This model significantly reduces development time and effort but also has some limitations, such as less control and a potential vendor lock-in. In general, it is preferred for the rapid development of applications with standard backend needs.

Serverless Computing vs. Platform-as-a-Service

Serverless computing and Platform-as-a-Service (Paas) both provide developers with environments to build and deploy applications without the need to manage the underlying infrastructure. However, they differ in the level of abstraction they offer for developers.

The serverless model runs individual functions as responses to events while providing full server management and runtime environments. Because it can be automatically scaled and responds dynamically to demand, serverless is suitable for organizations and developers with fluctuating workloads.

In contrast, PaaS provides a more holistic environment for developing and deploying applications. By providing a suite of tools and services, including OSes, middleware, and database management systems, PaaS reduces the complexity of managing multiple hardware and software layers. This model requires developers to handle some aspects of scaling and infrastructure maintenance, providing a balance of control and convenience. This makes PaaS more suitable for organizations that require a complete development and deployment environment and have consistent workloads.

Serverless Computing vs. Infrastructure-as-a-Service

Serverless computing and Infrastructure-as-a-Service (IaaS) cater to development and testing needs in different ways.

Serverless computing focuses on abstracting the infrastructure and ensuring automated and instant responses to demand. This provides a stable and highly functional environment for applications and tasks with unpredictable workloads.

In the IaaS model, the cloud provider supplies the infrastructure (VMs, storage, networks) over the internet. Developers do not have to manage physical servers, but they are responsible for managing operating systems, middleware, runtime, and the application itself. This gives them more control and flexibility over configurations but also more responsibility than with other computing models. IaaS is suitable for applications with steady workloads and resource consumption.

Serverless Computing and Kubernetes

Integrating serverless computing with Kubernetes involves blending serverless event-driven, scalable functions with Kubernetes’ container orchestration capabilities. While Kubernetes does not provide a native serverless framework, it can be extended to support serverless workloads using open-source projects such as:

• Knative. Developed by Google, this serverless tool provides a set of middleware components for building serverless applications through features such as automatic scaling and event-driven architecture.
• Kubeless. This Kubernetes-native framework provides auto-scaling, API routing, and other functionalities for deploying small units of code without managing the underlying infrastructure.
• OpenFaaS. This framework for building serverless functions with Kubernetes allows developers to deploy functions in any language and breaks up even complex applications into a series of manageable microservices.
• Fission. This serverless framework allows developers to quickly create serverless functions from code snippets in various languages.
• Nuclio. This tool optimizes the performance of event-driven applications by focusing on data processing in real-time.
• OpenWhisk. Developed by Apache, this platform supports a variety of languages and enables integration with a wide range of event sources and services.

The Rise of Serverless Computing

Initially, serverless computing emerged as a solution to the overhead and complexity of server management. It allowed developers to focus on the code while the cloud provider handled maintenance, updates, and management of the underlying infrastructure. This contributed to cost efficiency, especially in organizations with variable workloads and unpredictable traffic. Over time, serverless computing has expanded to provide other cloud services, such as storage, databases, etc., all operating on abstracted management.

Experts predict that serverless computing will become crucial to cloud strategy and application development. As businesses continue to seek agility, scalability, and cost-effectiveness for their operations, serverless architecture will be tasked with providing more advanced solutions across multiple industries and applications. This growth will be fueled by advancements in cloud technologies, such as improved cold start times, enhanced programming models, and smarter support and troubleshooting. Additionally, serverless computing is also expected to play an important role in fields such as edge computing and IoT, which require the efficient management of sporadic, event-driven workloads.

The Evolving Landscape of Serverless Computing

Serverless computing provides an innovative and more efficient approach to application development and deployment thanks to its inherent agility, flexibility, and scalability. As the model matures, it is expected that it will integrate more with existing architectures and that its adoption will spread across a variety of sectors and industries.