Web development keeps changing, and more developers now use serverless functions to build apps that scale well, cost less, and adapt quickly. Serverless functions also called Function-as-a-Service (FaaS), let you run backend code when events happen without needing to set up or manage servers. Big cloud companies like AWS (Lambda), Google Cloud (Cloud Functions), and Microsoft Azure (Azure Functions) have made it easy to deploy and grow these functions.
In this article, we’ll look at the main ways people use serverless functions in today’s web development. We’ll show how they make complex tasks simpler and cut down on work for developers and companies.
What Are Serverless Functions?
Let’s get a quick grasp of serverless functions before we look at how people use them.
Serverless functions work as small independent pieces of code. They spring into action when certain things happen, like web requests, file uploads, or changes in databases. They grow or shrink on their own to meet demand. Don’t let the name fool you – “serverless” doesn’t mean there are no servers. It just means the cloud provider takes care of all the behind-the-scenes stuff.
These functions come with some perks:
You pay for what you use: The bill reflects just the computer time you’ve used.
They grow with you: You don’t have to set up load balancers or clusters.
Less work for you: You can focus on writing code instead of managing the nuts and bolts.
Now, let’s see how people are putting serverless functions to work in real-world web apps.
1. Handling HTTP Requests and APIs
Serverless functions often build RESTful APIs or microservices to handle HTTP requests.
You can deploy functions that respond to specific HTTP methods (GET, POST, PUT DELETE) instead of maintaining a web server to route and process requests. This structure works well for microservices, headless CMSs, and backend-for-frontend (BFF) patterns.
Example:
Building APIs to support mobile app backends.
Making contact forms that trigger functions to send emails.
Acting as a go-between and changing data among different third-party APIs.
Benefits:
Quick deployment
Immediate scaling during traffic peaks
No need to run a complete web server or framework
2. Form Submission and Webhooks
Serverless functions are great for asynchronous, event-driven situations like form submissions and webhooks. When a user submits a form, or a third party service posts to your application, a serverless function can do the following:
Validate and sanitize the input.
Store it in a database.
Trigger additional services, e.g. sending a notification email or logging the event.
Examples could include:
Processing newsletter signups, or adding users to a mailing list.
Receiving Stripe or Shopify webhooks to update orders or send confirmation emails.
Benefits include completion in less time than a user would notice perceived delay, a secure environment isolated from other processes, and the ability to scale when events increase.
3. Authentication and Authorization
Authentication is paramount in web apps today. Serverless functions can be utilized to handle secure token-based authentication and authorization logic.
Rather than exposing critical logic to the client side or overloading an orchestration server, serverless functions can:
Validate a JWT or OAuth token.
Implement role-based access control.
Integrate with identity providers like Auth0 or Firebase Auth.
Example:
Validating users before accessing a dashboard.
Authorizing things an admin can do, like deleting a record.
Benefits:
More security
Decentralized and isolated logic
Seamless integration with third-party auth services
4. Real-Time File and Image Processing
Serverless functions are a great way to process media files while an end user is uploading or accessing them.
For example, you can trigger a function when a user uploads an image to cloud storage, and the function can:
Resize the image
Convert formats (from PNG to WebP, for example)
Generate thumbnails
Conduct virus scanning
Example:
Creating responsive images for responsive web design.
Transcoding audio or video files for streaming.
Benefits:
Simple on-demand, event-driven processing
Reduces the front-end workload of modifying files or data.
Can be chained together to make compelling more sophisticated processing pipelines.
5. Scheduled Tasks (Cron Jobs)
Serverless platforms can invoke functions on a schedule using cron syntax, which makes them well-suited for scheduled background processing such as:
Example:
Sending daily report emails or notifications.
Cleaning up old entries in databases.
Fetching data from third-party APIs and storing results.
Benefits:
Your application does not need a dedicated server that is running 24/7
Reliability with retry logic
Easy version control and management
6. Serverless GraphQL Resolvers
Serverless functions work well with GraphQL architectures where each function can be the resolver for a certain query or mutation.
It is an exciting way to build APIs dynamically and have development teams be more agile in building interfaces without monolithic backends.
For example:
Resolving user profile queries.
Doing a mutation to update user preferences.
Advantages:
Very fine grain control over each resolver
Easy to scale later and deploy
Best for JAMstack or headless CMS types of models
7. Chatbots and Real-Time Communication
Many modern applications include chatbots and/or real-time messaging capabilities. Serverless functions can handle incoming chat messages, call external APIs (like GPT or Dialogflow), and send a response back immediately.
Example:
Processing incoming chat messages and auto-generating automated responses.
Recording chatbot chat sessions and potential sentiment analysis.
Benefits:
Low latency and high concurrency.
Stateless and disposable by design.
Easy integration with messaging APIs such as Twilio or Slack.
8. Data Enrichment and Integration with APIs
Many modern applications have many external APIs that you can use. You could leverage serverless functions to bring in, aggregate, transform, and enrich data from APIs and send that data to the frontend or store it in a database.
Example:
Aggregating weather, location or financial data from external APIs.
Normalizing and storing data for analytics.
Benefits:
You have a clear separation of data logic
Decreases burden on the frontend
Perfect for microservices and modular codebases
9. E-commerce transactions and payment processing
Serverless functions can safely manage sensitive actions such as:
Starting or confirming payments.
Creating invoices.
Updating inventory and order statuses.
Example:
Creating a checkout endpoint that works with Stripe.
Sending shipment notifications once the order is fulfilled.
Benefits:
Improved security through isolation
Compliance support (E.g PCI DSS)
Functions that can be easily audited and tested
10. A/B Testing and Feature Toggles
Are you looking to test new features only with a subset of users? Serverless functions can be used to dynamically control feature flags and A/B test logic.
Example:
Determining which variation of a homepage to display
Turning on new UI components only to internal users
Advantages:
No need to redeploy the entire app
Enable fast iterations and testing
Can be configured with environment variables or remote config services
Conclusion
Serverless Functions have changed the way developers think about web development. From building a startup MVP to scaling a global application, they help enable more development capabilities while removing infrastructure considerations to develop more quickly.
Their functionality to perform aleatory stateless actions, based on real world events, alongside auto-scaling and cost effectiveness, will make serverless functions an important piece of the modern web development tool kit.
As the serverless ecosystem matures, the variety of use cases will continue to extend. Adopting this architecture today, will set developers up for a future that is more modular, efficient, and resilient.
