Building scalable infrastructure that stays type-safe

Over the past six years working with UK e-commerce consultancies, I've architected and deployed numerous cloud-native integrations on Google Cloud Platform. This post shares key lessons learned from building systems that handle thousands of transactions daily — and how keeping their contracts typed end to end kept them maintainable.

When building scalable infrastructure, I've found these principles essential.

Event-driven architecture

Using Pub/Sub for decoupled services allows each component to scale independently. When an order comes in, we publish an event rather than making synchronous calls to downstream services.

order-handler.ts

import { PubSub } from "@google-cloud/pubsub";
 
export async function handleOrder(req, res) {
  const pubsub = new PubSub();
  const topic = pubsub.topic("order-processing");
 
  await topic.publish(Buffer.from(JSON.stringify(req.body)));
  res.status(200).send("Order queued");
}

Infrastructure as code

Terraform enables reproducible deployments across environments. Every piece of infrastructure should be version-controlled and reviewable.

Observability first

Logging and monitoring from day one saves countless debugging hours. Cloud Logging and Cloud Monitoring should be configured before any business logic is written.

Real-world example: order processing pipeline

For a major British retailer, we built an order processing pipeline that:

Receives orders via webhook from BigCommerce
Validates and enriches order data
Routes to appropriate fulfillment systems based on product type
Handles retries and dead-letter queues for resilience

The entire system runs on Cloud Functions and Cloud Tasks, scaling automatically based on demand.

Lessons learned

Start simple — don't over-engineer. Begin with synchronous calls, then move to event-driven when you actually need it.
Monitor everything — custom metrics for business KPIs are as important as technical metrics.
Plan for failure — every external call will fail eventually. Design your retry logic carefully.

Conclusion

Cloud architecture is about making intentional trade-offs. Understanding your constraints and requirements is key to building systems that scale while remaining maintainable.

The best architecture is one that solves today's problems without creating tomorrow's technical debt.