What is AWS Lambda?A Beginner’s Guide to Serverless Computing in 2025

Introduction

Amazon Web Services (AWS) offers a serverless computing solution called AWS Lambda. Functions and self-contained applications written in one of the supported languages and runtimes are created by users and uploaded to AWS Lambda, which performs them in a flexible and effective way.

Any type of computer operation can be completed by the Lambda functions, including calling APIs, interacting with other AWS services, processing data streams, and serving web pages.

The idea behind “serverless” computing is that you can perform these tasks without having to worry about maintaining your own servers. All of the infrastructure is handled for you via AWS Lambda, a completely managed service. Therefore, “serverless” does not imply that no servers are used; rather, it just indicates that the servers are used., the operating systems, the network layer and the rest of the infrastructure have already been taken care of, so that you can focus on writing application code.

How does AWS Lambda work?

Every Lambda function operates within a separate container. Lambda creates a function, bundles it into a new container, and then runs that container on an AWS-managed multi-tenant cluster of computers. Each function’s container is given the required amount of RAM and CPU power before the functions begin to operate. The RAM that was initially allotted is multiplied by the duration of the function’s execution when it is finished. Following that, the clients are billed according to the memory allotted and the duration of time required for the function to execute.

AWS is in charge of managing AWS Lambda’s whole infrastructure layer. Although customers don’t have much control over how the system functions, they also don’t have to worry about maintaining the underlying computers, preventing network contention, or other issues—AWS handles these for them.

Additionally, adopting AWS Lambda might save you time on operational responsibilities because the service is fully controlled. Even if you lose the flexibility of running your own infrastructure, you may devote more effort to the application code when there is no infrastructure to maintain.

The ability to run several instances of the same function or of various functions from the same AWS account simultaneously is one of AWS Lambda’s unique architectural features. Furthermore, Lambda does not care about variations in concurrency based on the time of day or day of the week; you are only billed for the computations your functions use. Because of this, implementing highly scalable cloud computing solutions is an excellent fit for AWS Lambda.

Why is AWS Lambda an essential part of the Serverless architecture?

When building Serverless applications, AWS Lambda is one of the main candidates for running the application code. Typically, to complete a Serverless stack you’ll need:

  • a computing service;
  • a database service; and
  • an HTTP gateway service.

On AWS, Lambda serves as the compute service’s main function. Along with API Gateway, DynamoDB, and RDS, it also connects with a wide range of other AWS services and serves as the foundation for serverless solutions for AWS users. Many of the most widely used languages and runtimes are supported by Lambda, making it suitable for a broad spectrum of serverless developers.

What are the most common use cases for AWS Lambda?

Due to Lambda’s architecture, it can deliver great benefits over traditional cloud computing setups for applications where:

  • individual tasks run for a short time;
  • each task is generally self-contained;
  • there is a large difference between the lowest and highest levels in the workload of the application.

The following are some of the most typical AWS Lambda use cases that meet these requirements:
APIs that can grow. A single Lambda function execution can handle a single HTTP request when creating APIs with AWS Lambda. Through Amazon API Gateway, different API components can be routed to various Lambda functions. Different components of your API can scale differently based on current usage levels since AWS Lambda automatically adjusts individual functions based on demand. This makes it possible to set up flexible and affordable APIs.

data processing. Lambda functions are best suited for data processing that is event-based. AWS Lambda can be easily integrated with data sources like Amazon DynamoDB and triggered for certain data events. Because it may be used, for example, to carry out some task each time an item in DynamoDB is created or modified, Lambda is a good fit for things like analytics, counters, and notifications.

Task automation

AWS Lambda is a great option for automating a variety of business operations that don’t always require a full server because of its event-driven architecture and flexibility. This could entail carrying out planned tasks that tidy up your infrastructure, processing data from forms on your website, or moving data across datastores as necessary.

Supported languages and runtimes

While not all programming languages are now supported by AWS Lambda, it does support several of the most widely used languages and runtimes. The complete list of supported items is as follows:

  • Node.js 8.10
  • Node.js 10.x (normally the latest LTS version from the 10.x series)
  • Node.js 12.x (normally the latest LTS version from the 12.x series)
  • Python 2.7
  • Python 3.6
  • Python 3.7
  • Python 3.8
  • Ruby 2.5
  • Java 8 – This includes JVM-based languages that can run on Java 8’s JVM — the latest Clojure 1.10 and Scala 2.12 both run on Java 8 so can be used with AWS Lambda
  • Java 11
  • Go 1.x (latest release)
  • C# — .NET Core 1.0
  • C# — .NET Core 2.1
  • PowerShell Core 6.0

These runtimes are all offered on an Amazon Linux or Amazon Linux 2 environment and are all maintained by AWS. AWS offers an SDK for each of the supported languages, which facilitates the development of your Lambda functions and their integration with other AWS services.
There are still certain runtimes in the pre-release phase. The official documentation makes no mention of these runtimes, which are being developed as part of AWS Labs:

  • Rust 1.31
  • C++

The C++ runtime also serves as an example for creating custom runtimes for AWS Lambda. See the AWS docs for the details of how to create a custom runtime if your language isn’t supported by default.

Benefits of using AWS LambdaF

AWS Lambda has a few unique advantages over maintaining your own servers in the cloud. The main ones are:

Pay for each use. You only pay for the computation that your functions utilize using AWS Lambda, along with any network traffic that is produced. This kind of invoicing is typically more economical for workloads that vary greatly depending on the time of day.


Infrastructure that is well maintained. You no longer have to worry about the underlying servers because AWS handles this for you now that your operations are operating on the managed AWS infrastructure. Significant savings on operational duties like network layer management and operating system upgrades may arise from this.


Automatic scaling. AWS Lambda creates the instances of your function as they are requested. There is no pre-scaled pool, no scale levels to worry about, no settings to tune—and at the same time your functions are available whenever the load increases or decreases. You only pay for each function’s run time.

Tight integration with other AWS products.Because of AWS Lambda’s integrations with services like DynamoDB, S3, and API Gateway, you can create fully functional applications inside of your Lambda functions.

Limitations of AWS Lambda

While AWS Lambda has many advantages, there are a few things you should know before using it in production.

Cold start time

There may be a small lag between the event and the function’s execution when an event initiates the function. If your function hasn’t been utilized in the last 15 minutes, the delay can approach 5–10 seconds, making it challenging to rely on Lambda for latency-critical applications.. There are ways to get around it, such as the one we discussed in our blog post.

Function limits

The Lambda functions have a few limits applied to them:

Run time or execution time. After 15 minutes of operation, a Lambda function will time out. It is impossible to alter this restriction. AWS Lambda might not be the best option for your assignment if it usually takes more than 15 minutes to run your function.
The function’s available memory. With a 64MB increment, the RAM available to the Lambda functions can be set between 128MB and 3,008MB.

Code package size. The zipped Lambda code package should not exceed 50MB in size, and the unzipped version shouldn’t be larger than 250MB.

Concurrency. By default, the concurrent execution for all AWS Lambda functions within a single AWS account are limited to 1,000. (You can request a limit increase for this number by contacting AWS support.)

When Lambda executions exceed your concurrency limit, they will be throttled and made to wait for other processes to complete.
The size of the payload. The largest payload size that Amazon API Gateway can manage is 10MB when using it to launch Lambda functions in response to HTTP requests (i.e., when developing a web application).

Not always cost-effective

You only pay for the function runtime that is actually used on AWS Lambda, plus any other fees like network bandwidth. For some usage patterns, such as cron jobs or other on-demand tasks, this can result in significant cost reductions. However, the cost of AWS Lambda rises in proportion to the load on your application, and it may wind up costing more than comparable infrastructure on AWS EC2 or other cloud providers.

Limited number of supported runtimes

Although bespoke runtimes can be added using AWS Lambda, the process of creating them can be somewhat laborious. Therefore, you might be better suited using AWS EC2 or another cloud provider if Lambda does not support the version of the programming language you are using.

You may be like this:

Top 10 AWS Services You Should Know in 2025

Server Side Rendering vs Client Side Rendering 

₹25,000.00

SAP SD S4 HANA

SAP SD (Sales and Distribution) is a module in the SAP ERP (Enterprise Resource Planning) system that handles all aspects of sales and distribution processes. S4 HANA is the latest version of SAP’s ERP suite, built on the SAP HANA in-memory database platform. It provides real-time data processing capabilities, improved…
₹25,000.00

SAP HR HCM

SAP Human Capital Management (SAP HCM)  is an important module in SAP. It is also known as SAP Human Resource Management System (SAP HRMS) or SAP Human Resource (HR). SAP HR software allows you to automate record-keeping processes. It is an ideal framework for the HR department to take advantage…
₹25,000.00

Salesforce Administrator Training

I am text block. Click edit button to change this text. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut elit tellus, luctus nec ullamcorper mattis, pulvinar dapibus leo.
₹25,000.00

Salesforce Developer Training

Salesforce Developer Training Overview Salesforce Developer training advances your skills and knowledge in building custom applications on the Salesforce platform using the programming capabilities of Apex code and the Visualforce UI framework. It covers all the fundamentals of application development through real-time projects and utilizes cases to help you clear…
₹25,000.00

SAP EWM

SAP EWM stands for Extended Warehouse Management. It is a best-of-breed WMS Warehouse Management System product offered by SAP. It was first released in 2007 as a part of SAP SCM meaning Supply Chain Management suite, but in subsequent releases, it was offered as a stand-alone product. The latest version…
₹25,000.00

Oracle PL-SQL Training Program

Oracle PL-SQL is actually the number one database. The demand in market is growing equally with the value of the database. It has become necessary for the Oracle PL-SQL certification to get the right job. eLearning Solutions is one of the renowned institutes for Oracle PL-SQL in Pune. We believe…
₹25,000.00

Pega Training Courses in Pune- Get Certified Now

Course details for Pega Training in Pune Elearning solution is the best PEGA training institute in Pune. PEGA is one of the Business Process Management tool (BPM), its development is based on Java and OOP concepts. The PAGA technology is mainly used to improve business purposes and cost reduction. PEGA…
₹27,000.00

SAP PP (Production Planning) Training Institute

SAP PP Training Institute in Pune SAP PP training (Production Planning) is one of the largest functional modules in SAP. This module mainly deals with the production process like capacity planning, Master production scheduling, Material requirement planning shop floor, etc. The PP module of SAP takes care of the Master…
X
WhatsApp WhatsApp us
Call Now Button