System Design Interview Questions
Practice 992 real System Design interview questions for 2026 — System Design interview questions drawn from actual interviews with detailed solutions to power focused interview preparation. Coverage spans big tech patterns and company-specific flavors from Meta, Amazon, OpenAI, DoorDash, and Google, emphasizing software-engineering fundamentals: high-level architecture, APIs, data models, scaling strategies, and component-level tradeoffs you’ll need to codify on a whiteboard or virtual diagram tool. What’s distinctive in 2026: interviewers evaluate your ability to reason about capacity, latency, consistency, fault tolerance, and operational ownership while making measurable tradeoffs; expect more questions about AI/LLM inference pipelines, vector search and feature stores alongside classic problems like caching, sharding, messaging, and geo-distribution. Prepare by practicing clear HLD-to-LLD transitions, writing concise API contracts, doing back-of-envelope capacity math, and running timed mock interviews that force diagram clarity and follow-up handling. Focus on metrics, failure modes, and deployment/monitoring choices — those separate good answers from great ones.
"I got asked a hardcore MCM DP question and I saw it on PracHub as well. Solved that question in 5 minutes. Without PracHub I doubt I could solve it in 5 hours. Though somehow didn't get hired, perhaps I guess I solved it too fast? /s"
"Believe me i'm a student here jn US. Recently interviewed for MSFT. They asked me exact question from PracHub. I saw it the night before and ignored it cause why waste time on random sites. I legit wanna go back and redo this whole thing if I had chance. Not saying will work for everyone but there is certainly some merit to that website. And i'm gonna use it in future prep from now on like lc tagged"
"10 years of experience but never worked at a top company. PracHub's senior-level questions helped me break into FAANG at 35. Age is just a number."
"I was skeptical about the 'real questions' claim, so I put it to the test. I searched for the exact question I got grilled on at my last Meta onsite... and it was right there. Word for word."
"Got a Google recruiter call on Monday, interview on Friday. Crammed PracHub for 4 days. Passed every round. This platform is a miracle worker."
"I've used LC, Glassdoor, and random Discords. Nothing comes close to the accuracy here. The questions are actually current — that's what got me. Felt like I had a cheat sheet during the interview."
"The solution quality is insane. It covers approach, edge cases, time complexity, follow-ups. Nothing else comes close."
"Legit the only resource you need. TC went from 180k -> 350k. Just memorize the top 50 for your target company and you're golden."
"PracHub Premium for one month cost me the price of two coffees a week. It landed me a $280K+ starting offer."
"Literally just signed a $600k offer. I only had 2 weeks to prep, so I focused entirely on the company-tagged lists here. If you're targeting L5+, don't overthink it."
"Coaches and bootcamp prep courses cost around $200-300 but PracHub Premium is actually less than a Netflix subscription. And it landed me a $178K offer."
"I honestly don't know how you guys gather so many real interview questions. It's almost scary. I walked into my Amazon loop and recognized 3 out of 4 problems from your database."
"Discovered PracHub 10 days before my interview. By day 5, I stopped being nervous. By interview day, I was actually excited to show what I knew."
"I recently cleared Uber interviews (strong hire in the design round) and all the questions were present in prachub."
"The search is what sold me. I typed in a really niche DP problem I got asked last year and it actually came up, full breakdown and everything. These guys are clearly updating it constantly."
Design an ad click tracking system
Design a system to track ad impressions and clicks and support: 1. Online serving / real-time analytics - Near-real-time counters (e.g., clicks per...
Design an e-commerce price tracking service
Design a backend system similar to popular price-tracking sites that monitor product prices on large e-commerce platforms (for example, a site that tr...
Design notification and project architecture
System Design: Multi-Channel Notification Platform Design a scalable Notification System that supports real-time and scheduled messages across multipl...
Design user communication functions
In-Memory Communication Manager Context Build a simple in-memory component that tracks which users can communicate with each other. Treat a communicat...
Design cloud & k8s architecture
Technical Screen: Kubernetes, Cloud Services, and Secure CI/CD Context You are designing and operating services on Kubernetes in a public cloud. Answe...
Compare cloud compute; design Kubernetes security and CI/CD
Cloud Compute Models, Testing Strategies, Kubernetes Deep Dive, Security, and CI/CD to GKE Context You are designing and operating services across pub...
Design OOD for probabilistic Minesweeper
Object-Oriented Design: Minesweeper with Per-Cell Mine Probabilities Context Design an object-oriented Minesweeper game. The board is a grid of cells....
Design real-time top-k items
Design: Real-Time Top-k Most Purchased Items You are given an unbounded stream of purchase events with schema: - purchase_event: (customer_id, item_id...
Design an IP blacklist API
Design an API and backend service for an IP firewall blacklist system. The service should allow security administrators or automated abuse-detection s...
Design a Therapy Matching Marketplace
Design the backend for a marketplace that matches patients with therapists. The platform should support: - Patients searching for therapists by specia...
Design scalable media storage and delivery
System Design: Global UGC Photos and Short Videos Store/Delivery Context Design a globally distributed system to store and deliver user-generated phot...
Design Ticket Booking Auto Release
System Design: Auto-expiring Ticket Reservations Problem Design a ticket-booking system where a reserved ticket automatically returns to the inventory...