Systems Design Interview & Architecture Guide

For developers building and designing systems in DoD / Coast Guard IL2/IL4 environments on AWS GovCloud using EKS, PostgreSQL, Terraform, FluxCD, Prometheus/Grafana.

Based on principles from Designing Data-Intensive Applications (2nd ed., Kleppmann & Riccomini, 2026), adapted for our specific stack and compliance requirements.

System Design Interview Framework

Every system design interview answer should follow this structure. Practice thinking through each step — interviewers care more about your reasoning process than arriving at a "perfect" answer.

Step 1: Requirements & Constraints (3-5 minutes)

Don't jump into drawing boxes. Clarify what you're building first.

Functional requirements — What does the system do? What are the core user stories?