Architect Interview Final

Congratulations! You have completed the full 180+ module Toolliyo curriculum. In this final module, we focus on the high-level **System Design** questions asked at the Senior and Staff Engineer level for Microservices positions.

1. Scenario: Scale a global e-commerce site

Question: "How would you design a system to handle 100,000 orders per second during Black Friday?"

Answer Structure:

• Frontend: Static assets on a CDN (Azure Front Door / Cloudflare).
• Entry: API Gateway with Rate Limiting and Circuit Breakers.
• Auth: Cached JWT tokens in Redis.
• Write Path: Queue all orders in RabbitMQ/Service Bus immediately to decouple processing from the UI.
• database: Sharded PostgreSQL or a NoSQL database like CosmosDB for unlimited write throughput.
• Observability: Real-time dashboards with OpenTelemetry to spot hotspots instantly.

2. The CAP Theorem Decision

In a distributed system, you can only have two out of three: **Consistency**, **Availability**, and **Partition Tolerance**. For a modern microservice app, we almost always choose **AP** (Availability & Partition Tolerance). We accept that data might be slightly stale for a few milliseconds (Eventual Consistency) in exchange for the system NEVER going down.

MASTER ARCHITECT CAPSTONE COMPLETE.

You are now ready to lead enterprise-grade .NET teams and design cloud-native systems for millions of users. Keep building.