How I Approach System Design Interviews 🏗️

How I Approach System Design Interviews 🏗️

One thing I’ve learned about system design: it’s not about choosing the most advanced technology. It’s about making the right trade-offs.

When I approach a system design interview, I follow a structured process:

🔹 1. Understand the Requirements:- Clarify what the system needs to do and identify functional and non-functional requirements.

🔹 2. Estimate the Scale:- Think about expected users, request volume, data storage, and traffic growth.

🔹 3. Design the APIs and Data Model:- Define how services communicate and how data will be stored, accessed, and updated.

🔹 4. Build the High-Level Architecture:- Identify the main components and decide where databases, caches, queues, and services fit.

🔹 5. Think About Failures:- What happens when a service goes down? How do we handle retries, duplicate requests, and traffic spikes?

🔹 6. Discuss Trade-offs:- Every design has trade-offs. The goal is to explain why a particular approach makes sense for the problem.

Working with backend systems, especially payment infrastructure, has reinforced one important lesson: reliability, idempotency, and observability should be part of the design—not an afterthought.

A good system design isn't the most complicated one. It's the one that solves the problem reliably and can evolve as requirements change.

💬 Question for fellow developers: What's the first thing you focus on when starting a system design interview?