What is serverless computing?

In serverless computing, developers build and deploy applications on infrastructure managed by third-party cloud providers. Rather than maintaining dedicated servers continuously, the cloud provider automatically provisions, scales, and maintains underlying server components based on actual demand.

This model represents an abstraction layer above virtualized computing. The cloud provider handles operating system management, security patching, file system administration, capacity planning, load balancing, monitoring, and logging. This frees development teams to concentrate on application design while leveraging cost-effective, efficient, and highly scalable infrastructure.

How does serverless architecture work?

Serverless architecture has emerged as a design pattern particularly suited to modern applications. Applications typically consist of two components: a frontend (the user interface elements customers interact with) and a backend (the underlying engine managing data storage, processing, and business logic).

Traditional server-based approaches run the frontend through a content distribution network (CDN) while the backend runs continuously on hardware or software, waiting for incoming requests. Serverless architecture instead deploys backend code to cloud infrastructure managed by a provider. A typical serverless backend uses event-driven architecture with small, independent services that communicate by publishing, consuming, or routing events as needed. The provider dynamically scales cloud resources across these services based on current demand.

Serverless functions

Functions are compact code units designed to perform a single task. Each function requires computing resources—CPU and memory—to execute. The cloud provider allocates these resources on its serverless platform only when the function needs to run.

Specific events trigger code execution. For example, a user clicking a 'Submit' button in an application could activate a serverless function that performs a database query and returns results to the user.

Scaling based on requests

As a function receives more requests, it requires additional resources to process them. The serverless architecture continuously monitors load and provisions additional cloud resources as needed. A single function can handle one request or one million requests without code modifications, constrained only by downstream dependencies such as network latency or database performance.

When a function stops receiving requests, the cloud provider scales down the underlying infrastructure to minimize costs. Resources are allocated exclusively when needed; if usage drops to zero, the environment can scale down to zero.

Why is serverless computing important?

Early internet applications required organizations to purchase and maintain physical servers, typically housed in on-premises data centers or colocation facilities. This approach proved expensive because most applications consumed only a fraction of available server capacity at any given time.

Cloud computing initially addressed this by enabling customers to create virtual machine instances on provider infrastructure. However, customers remained responsible for provisioning, configuring, updating, and scaling these virtual servers.

Cloud providers subsequently introduced serverless technologies to enhance organizational agility and further reduce costs. Serverless computing allows developers to deploy code, manage data, and integrate applications without handling deployment and infrastructure management responsibilities.

Increased developer productivity

Development teams concentrate on building applications rather than configuring infrastructure. Reduced operational burden accelerates time-to-market. Developers can respond to customer feedback more quickly and release application updates more frequently.

Efficient scalability

Cloud vendors provide automatic scaling in serverless environments, allowing applications to scale from zero to peak demand automatically. Traditional environments experience performance degradation under peak load, requiring reconfiguration that consumes additional time.

Lower costs

Organizations pay only for CPU, memory, and computing resources consumed during code execution. Idle resources incur no charges. This pay-for-value billing approach delivers superior resource utilization and eliminates waste from overprovisioning.

What are the use cases of serverless computing?

Numerous applications and systems gain advantages from serverless architecture.

Stateless application development

Serverless architecture suits asynchronous, stateless applications that do not retain client data between sessions. Chatbots, task schedulers, and IoT applications exemplify this category. Coca-Cola leveraged AWS serverless services including AWS Lambda to increase its order fill rate.

Batch processing

Batch processing applications periodically execute high-volume, repetitive data operations such as backups, filtering, and sorting. These workloads align well with serverless environments that scale substantially when needed and incur no costs during idle periods.

Vertex Pharmaceuticals used AWS to accelerate its image segmentation speed by 11 times. The company employed AWS Step Functions to expedite the meticulous, time-consuming processes involved in analyzing microscope images of biological samples from experiments.

Real-time data analytics

Serverless computing excels in real-time streaming engines that enhance customer responsiveness. Serverless applications can process massive volumes of streaming data from hundreds of thousands of sources with minimal latency and high throughput. Organizations can extract insights in seconds rather than minutes.

Genentech employs AWS serverless functionality for clinical data analysis. Researchers now complete tasks in hours that previously required weeks.

Business process automation

Organizations can apply serverless approaches to business process automation, digitizing repetitive and time-consuming tasks. Developers concentrate on translating business requirements into application code without managing servers.

Taco Bell transitioned to AWS serverless for its ecommerce platform. The migration delivered 90% reductions in infrastructure costs and 90% reductions in code complexity.

What are the types of serverless architecture?

In serverless architecture, the cloud provider manages backend operations for applications. Developers deploy custom code, and the provider dynamically allocates resources whenever code executes. The cloud solution also delivers backend functionality accessible directly through APIs without requiring custom development.

Function as a service (FaaS)

Function as a service represents a serverless architecture enabling developers to write custom backend functions and deploy function code directly to cloud infrastructure. When an application invokes a function, the cloud provider executes it on existing server resources or creates new ones if necessary. These functions are termed serverless functions because their provisioning, management, and execution are abstracted from developers.

Backend as a service (BaaS)

Backend as a service grants developers API-based access to backend functions. APIs are mechanisms enabling two software components to communicate using defined specifications and protocols.

Cloud service providers offer API-based access to encryption, authentication, and cloud-accessible databases within their serverless environments. Developers can also leverage third-party backend services and applications. These serverless functions are prewritten and called directly within code.

What challenges can you face implementing serverless computing?

Although serverless architecture delivers practical advantages for developers, users, and organizations, it introduces specific technical trade-offs. Understanding these potential challenges enables designing more resilient serverless environments.

Cold starts

Cloud providers scale a serverless function's allocated resources to zero when unused. Upon receiving a new request, the serverless provider must initialize the execution environment from scratch and allocate fresh resources. This initialization process, termed a cold start, can introduce delays that affect time-sensitive applications. Organizations can mitigate this issue using features such as Provisioned Concurrency in AWS Lambda to maintain a set of core functions in an initialized, "warm" state.

Observability and debugging

In serverless, event-driven architectures, a single user action may trigger multiple independent functions and microservices across the network. This complexity makes monitoring, logging, and determining error root causes substantially more difficult. Teams adopting serverless architecture should ensure access to distributed tracing and specialized observability tools to maintain visibility into system data flows.

What is a serverless-first strategy?

Serverless architecture encompasses several defining characteristics:

  • Server infrastructure management remains the provider's responsibility
  • Pay-as-you-go service models
  • Effectively instantaneous scaling
  • Integrated fault tolerance

A serverless-first strategy emphasizes these principles throughout an organization's applications, operations, and development processes. Serverless-first companies and developers prioritize building using these tenets.

However, serverless computing does not suit all workloads. Organizations should incorporate non-serverless technologies as supporting architecture when necessary.

Is serverless architecture secure?

Cloud vendors implement a shared security model. The cloud provider secures the cloud infrastructure, while customers secure their applications and data within the cloud.

Serverless computing shifts responsibility for more infrastructure layers to the cloud provider than traditional virtualized server instances, including operating systems and networking. Customers must adhere to least privilege principles and apply serverless application security best practices.

In AWS FaaS solutions such as AWS Lambda, organizations can secure each resource using granular permissions through familiar tools like AWS Identity and Access Management. This approach strengthens the security posture of serverless applications.

How can AWS support your serverless computing requirements?

Amazon Web Services (AWS) provides extensive offerings supporting serverless computing. AWS serverless technology enables running code, managing data, and integrating applications without server management. AWS serverless solutions deliver automatic scaling, built-in high availability, and pay-for-use billing to enhance agility and optimize costs. These technologies also eliminate infrastructure and server management tasks including capacity provisioning and patching, allowing teams to concentrate on writing customer-focused code.

Serverless applications begin with AWS Lambda, an event-driven compute service natively integrated with more than 200 AWS services. Additional supporting services include:

  • AWS Step Functions is a serverless, visual workflow orchestration service enabling developers to build, manage, and scale complex applications by coordinating AWS Lambda functions, containers, and other AWS services
  • AWS Fargate to build serverless applications compatible with Amazon Elastic Container Service (Amazon ECS) and Amazon Elastic Kubernetes Service (Amazon EKS)
  • Amazon Aurora Serverless to build serverless databases that automatically scale capacity based on application needs
  • AWS AppSync to accelerate application development with scalable GraphQL APIs

Source: AWS News Blog