Building Event-Driven Applications: A Comprehensive Guide for Startups

There's something mesmerising about well-built event-driven applications. From handling real-time analytics to notification services and beyond, the efficiency and versatility they offer is impressive. At Softlancer, our team deeply understands the intricacies of these dynamic systems. Each day, we assist startups in building their MVPs (Minimum Viable Product) using effective patterns like event-driven architecture.

Understanding Event-Driven Architecture

An event-driven architecture is a design paradigm where an application's flow of control is determined by events like mouse clicks, sensor outputs, or messages from other programs. Events are central product functionality expressed as discrete, significant, domain-specific actions occurring over time.

Prerequisites

Before we jump into the thick of things, here are a few prerequisites:

Basic programming knowledge.
Understanding of the JavaScript language and Node.js.
AWS account to implement our server less backend.
Toolkit: AWS SDK version 3, AWS Lambda and Dynamo DB.

Building an Event-Driven App: A Step-By-Step Guide

Step 1: Install AWS SDK

Install AWS SDK using the Node.js command prompt.

npm install aws-sdk

Step 2: Initialise AWS and DynamoDB

We will first initialise AWS and DynamoDB with the relevant configurations. Error handling is taken care of by standard JavaScript promise handlers (.then, .catch).

const AWS = require('aws-sdk')
AWS.config.update({region: 'YOUR_REGION'})

// Initializing DynamoDB
const DynamoDB = new AWS.DynamoDB.DocumentClient();

Step 3: Implementing the Event Handler

For an event-driven system, handling the events is the most crucial part. The AWS Lambda service makes this process quite straightforward.

exports.handler = async (event, context) => {
  try {
          // handling the logic when an event is triggered
          await handleEvent(event);
      } catch (err) {
          console.log(err);
          return err;
      }
  }

Step 4: Deploying and Hosting

Once we have our application ready, we can deploy it using AWS serverless deployment options. Here, we'll use Amazon S3 for hosting our static site.

Use Case: Real-Time Analytics

Let's walk through an example where a startup wants to track real-time analytics of users visiting its website. The AWS Kinesis service tracks user activity as events. These events are then sent to a Lambda function, which processes the events and stores them in Dynamo DB.

Conclusion

Building event-driven applications can drastically improve the scalability and responsiveness of your system. AWS, with its plethora of services, makes it easy for startups to adopt this architectural style quickly and efficiently.

As you use this guide to navigate your journey towards building your event-driven MVP, remember that at Softlancer, we're here to support you every step of the way!

References

Frequently Asked Questions (FAQs)

What is an event in event-driven programming?
An event is any significant occurrence or happening relevant to the system. In software, these are often actions such as mouse clicks or keyboard inputs.
Why use an event-driven architecture?
Event-driven architecture helps improve scalability and responsiveness. It also allows for more efficient use of resources, as servers aren't left idle waiting for requests.
How does AWS Lambda work in an event-driven system?
AWS Lambda is a compute service that runs your code in response to events. It manages the compute infrastructure automatically, handling any scaling, patching, or server management necessary.
What is a serverless backend?
A serverless backend refers to applications where server-side logic is run in stateless compute containers maintainable by a third party. AWS Lambda is an example of this.
Where can I learn more about event-driven application development?
The AWS SDK developer guide and Lambda developer guide are excellent resources.