E-Commerce Platform on Microservices
An AWS EKS reference architecture for an e-commerce platform split into microservices coordinated by Kafka and the saga pattern. It scales browsing, search, and checkout independently while keeping payments PCI-compliant.
E-Commerce Platform on Microservices
An e-commerce platform handles browsing, cart, checkout, payment, inventory, and fulfillment — each with different load patterns and consistency needs. Splitting it into microservices lets teams scale and deploy each capability independently and isolate failures. Choose this for high-traffic online retail and marketplaces where a monolith has become a bottleneck. The price is distributed-systems complexity. This design runs on Amazon EKS.
Components
- API gateway: single entry point that authenticates, routes, and rate-limits.
- EKS: Kubernetes cluster running the catalog, cart, order, inventory, and payment services.
- Kafka (MSK): the event backbone for order events, inventory updates, and notifications.
- PostgreSQL (Aurora): database-per-service for transactional data.
- Elasticsearch (OpenSearch): powers product search and faceted browsing.
- Redis: caches catalog data, sessions, and cart state.
- CDN: serves the storefront and product images.
- Payment service: integrates PCI-compliant payment processors.
Data Flow
Shoppers browse via the CDN and the catalog service, with search served by Elasticsearch. Adding to cart updates Redis-backed cart state. Checkout starts a saga: the order service emits an event, payment authorizes, inventory reserves stock, and fulfillment is scheduled — each step compensating on failure. Kafka carries these events so services stay decoupled. Idempotency keys prevent duplicate charges on retries.
Scaling and Resilience
Scale read-heavy catalog and search horizontally and independently of checkout. Cache aggressively for browsing; reserve strong consistency for inventory and payment. The saga pattern coordinates distributed transactions without a global lock, using compensating actions to roll back. Circuit breakers isolate a failing service so it does not cascade. Run across Availability Zones and use canary releases per service.
Security
Keep cardholder data out of your services by delegating to a PCI-DSS-compliant processor and tokenizing payments. Authenticate at the gateway with OAuth 2.0 and enforce least privilege between services with a service mesh. Make payment and order operations idempotent to avoid double charges. Encrypt data in transit and at rest, and audit every order and refund.
Trade-offs and Alternatives
Microservices add operational overhead, distributed transactions, and eventual consistency that a monolith avoids. For smaller stores, a modular monolith or a managed commerce platform ships faster and costs less to run. Adopt microservices when independent scaling and team autonomy outweigh that complexity, and split along clear domain boundaries rather than all at once.