When interviewers ask you to design an AI-powered feature, they're testing system design judgment, not ML knowledge — this post shows how to treat the model as an unreliable dependency and reason about its latency, cost, and failure modes.
Interview Preparation
118 posts
Failover isn't just "promote a follower" — done carelessly, it produces split-brain and zombie-leader failures worse than the outage it was meant to prevent. Here's what fencing tokens, quorum election, and STONITH actually protect against.
Read replicas add read capacity and failover copies, but every write still funnels through one leader—so replicas alone won't fix a write bottleneck or guarantee fresh reads.
Most CAP theorem explanations conflate availability with freshness, CAP consistency with ACID consistency, and treat CP/AP as permanent labels. Here's how to state the trade-off correctly during a network partition.
Holding a million WebSocket connections is easy; delivering one message to users scattered across servers is the hard part. Here's why a broker alone doesn't solve fanout, and what a presence registry actually buys you.
A "Design Spotify" prompt mixes local controls, routine backend work, and hidden distributed-systems problems. Here's how to scope requirements so your limited interview time goes to what actually deserves architectural depth.
System design vocabulary is easy to reproduce, so a familiar diagram alone doesn't differentiate a candidate; the stronger signal is whether each architectural choice is tied to the actual workload, product risk, and operating constraints. The post walks through a notification-platform prompt to show what that judgment looks like in practice.
AI can speed up system design interview prep and create a false sense of readiness. Here's how to use it to sharpen your reasoning while keeping the thinking yours.
After years in one engineering role, interviewing gets rusty. Here is how to turn your day-to-day work into clear, specific answers an interviewer can follow.
A practical guide to using AI for software engineering interview prep, from behavioral answers to system design, without losing the details that make you credible.
