Event-Driven Microservices with Kafka and Temporal

Synchronous Coupling Kills Uptime

In a standard synchronous microservice architecture, Service A calls Service B. If Service B is down, Service A fails. This cascading failure is the bane of enterprise systems.

The Event-Driven Solution

We utilize Apache Kafka to decouple services. Instead of calling an API, Service A emits an event (OrderCreated). Service B listens for that event and processes it when it has capacity.

Handling Complex Distributed Workflows

Kafka is great for moving data, but terrible for orchestrating multi-step processes (like processing a payment, reserving inventory, and sending an email). For that, we use Temporal.

import { proxyActivities } from '@temporalio/workflow';
import type * as activities from './activities';

const { chargeStripe, reserveInventory, sendEmail } = proxyActivities<typeof activities>({
  startToCloseTimeout: '1 minute',
});

// A durable workflow. If the server crashes during this, 
// Temporal resumes exactly where it left off.
export async function processOrder(orderId: string) {
  await reserveInventory(orderId);
  await chargeStripe(orderId);
  await sendEmail(orderId);
}

This combination of Kafka for throughput and Temporal for reliability allows us to build systems that literally cannot fail silently.