Event buses: SNS/SQS vs EventBridge vs Event Grid — Best Practices in 2025 — Practical Guide (Feb 7, 2026)

Event buses: SNS/SQS vs EventBridge vs Event Grid — Best Practices in 2025

Level: Experienced

Event buses: SNS/SQS vs EventBridge vs Event Grid — Best Practices in 2025

As distributed systems evolve, event-driven architectures grow ever more critical for building scalable, decoupled applications. By early 2026, three cloud-native event bus technologies lead the landscape: AWS’s SNS/SQS, AWS EventBridge, and Microsoft Azure Event Grid. Choosing between these depends on your platform, use case complexity, and integration preferences. This article provides a practical guide for experienced engineers evaluating these services as of February 2026.

Prerequisites

Familiarity with event-driven design patterns and messaging paradigms (pub/sub, queues, topics).
Basic AWS and Azure knowledge, including IAM (AWS) or Role-Based Access Control (RBAC) and Cloud messaging concepts.
Understanding of common cloud integration points such as AWS Lambda, Azure Functions, and SaaS event sources.
Access to AWS Console (for SNS, SQS, EventBridge) and Azure Portal (for Event Grid) with permissions to create topics, queues, rules, and subscriptions.
Node.js or Python (or your preferred language) SDK setup for AWS and Azure to experiment with publishing and subscribing events.

Event Buses Overview

AWS SNS + SQS

Simple Notification Service (SNS) combined with Simple Queue Service (SQS) is the classic AWS pub/sub model. SNS functions as a topic-based publisher forwarding messages to multiple subscribers, while SQS queues act as durable buffers with pull consumption capabilities.

AWS EventBridge

EventBridge is AWS’s serverless event bus service designed for complex event routing and filtering. It supports custom event buses, partner event sources (e.g., SaaS integrations), and rich event pattern matching. As of version 2025.4, EventBridge supports native schema discovery and replay capabilities making debugging and event archiving straightforward.

Azure Event Grid

Event Grid is Azure’s highly scalable event routing service supporting both first and third-party event sources. It excels with native Azure service integration (Blob Storage, Resource Groups) and supports advanced filtering and dead-lettering out of the box.

Hands-on Steps: Implementing a Pub/Sub Event Flow

1. AWS SNS + SQS

Create an SNS topic and an SQS queue, then subscribe the queue to the topic for message delivery. Here’s an example in AWS CLI and Node.js SDK.

# Create SNS topic
aws sns create-topic --name MyAppTopic

# Create SQS queue
aws sqs create-queue --queue-name MyAppQueue

// Subscribe SQS queue to SNS topic in Node.js
import { SNSClient, SubscribeCommand } from "@aws-sdk/client-sns";
import { SQSClient, GetQueueAttributesCommand } from "@aws-sdk/client-sqs";

const sns = new SNSClient({ region: "us-east-1" });
const sqs = new SQSClient({ region: "us-east-1" });

async function subscribeQueueToTopic(topicArn, queueUrl) {
  // Get queue arn
  const attr = await sqs.send(new GetQueueAttributesCommand({
    QueueUrl: queueUrl,
    AttributeNames: ["QueueArn"]
  }));
  const queueArn = attr.Attributes?.QueueArn;

  // Subscribe
  const subscribeCmd = new SubscribeCommand({
    TopicArn: topicArn,
    Protocol: "sqs",
    Endpoint: queueArn
  });
  await sns.send(subscribeCmd);
  console.log("Subscription created");
}

2. AWS EventBridge

Set up an event bus, define rules that filter events, and add Lambda targets or other AWS services.

# Create a custom event bus
aws events create-event-bus --name MyCustomBus

// Put event to EventBridge custom bus
import { EventBridgeClient, PutEventsCommand } from "@aws-sdk/client-eventbridge";

const eb = new EventBridgeClient({ region: "us-east-1" });

async function putEvent() {
  const params = {
    Entries: [{
      Source: "my.app",
      DetailType: "UserSignup",
      Detail: JSON.stringify({ userId: "12345" }),
      EventBusName: "MyCustomBus"
    }]
  };
  await eb.send(new PutEventsCommand(params));
  console.log("Event sent");
}

3. Azure Event Grid

Create a custom topic, subscribe an Azure Function endpoint, and publish events via REST API or SDK.

# Create Event Grid topic (Azure CLI)
az eventgrid topic create --name mycustomtopic --resource-group myResourceGroup --location eastus

// Publish event to Event Grid (C# SDK)
using Azure.Messaging.EventGrid;
using Azure;

var topicEndpoint = new Uri("https://mycustomtopic.eastus-1.eventgrid.azure.net/api/events");
var credential = new AzureKeyCredential("");
var client = new EventGridPublisherClient(topicEndpoint, credential);

var eventGridEvent = new EventGridEvent(
    subject: "User/Signup",
    eventType: "UserCreated",
    dataVersion: "1.0",
    data: new { userId = "12345", timestamp = DateTime.UtcNow }
);

await client.SendEventAsync(eventGridEvent);
Console.WriteLine("Event published");

Common Pitfalls

SNS + SQS: Be cautious about message duplication; SQS guarantees at-least-once delivery, so idempotency is essential.
EventBridge: Event size maxes at 256 KB; large payloads require alternative storage (e.g., S3 references).
Event Grid: Default retry policies may delay event delivery; configure dead-lettering for tracing failed deliveries.
Cross-account permissions can be complex for AWS services; always audit IAM policies and resource policies to avoid access failures.
Filter expressions: EventBridge supports JSON pattern matching which is richer than SNS attribute-based filtering; misuse may cause silent event drops.
Latency considerations: SNS + SQS can have slight delays due to polling, whereas EventBridge and Event Grid provide near real-time event routing.

Validation

To verify your event bus setup:

Publish a test event/message to the bus or topic.
Use metrics dashboards (CloudWatch for AWS, Azure Monitor for Event Grid) to monitor delivery successes, throttles, and failures.
Inspect dead-letter queues (AWS) or dead-letter storage (Azure) for undelivered events.
Enable and review debugging logs, for example, enable EventBridge schema registry logging or Event Grid diagnostic settings.
Perform end-to-end tests by triggering subscribed consumers (Lambdas, Functions) and asserting on expected side effects.

Checklist / TL;DR

Choose SNS + SQS if: You need simple, durable pub/sub + queue patterns with manual scaling control, and you value broad support across AWS regions.
Choose EventBridge if: You require sophisticated event routing, partner SaaS integrations, schema discovery, and event replay within AWS.
Choose Event Grid if: You are invested in Azure ecosystem with native integration to Azure services and want enterprise-grade event delivery with flexible filtering.
Apply idempotent design in consumers wherever possible due to at-least-once delivery guarantees.
Always monitor event queues’ depths and failures using cloud-native monitoring tools.
Pay careful attention to payload size limits and event filtering capabilities.