High-Concurrency E-Commerce Backend

Django backend serving 50K concurrent users with zero downtime, secure payments, and real-time inventory.

The problem

The platform needed to scale order processing and payments without downtime while supporting multiple payment providers and real-time inventory accuracy.

Impact

Concurrent users: 50K, zero downtime
Payments: Stripe & PayPal, multi-method

Approach

1
Migrated legacy batch workflows onto Apache Airflow via Google Cloud Composer, standardizing orchestration across 70+ DAGs.
2
Built Dataflow ETL jobs to consolidate fragmented source systems into a unified BigQuery warehouse model.
3
Designed a Pub/Sub-based message routing layer on GCP with dead-letter queue strategies for guaranteed delivery.

Stack

Python
Django
Celery
Redis
Stripe
PayPal
JWT/OAuth2