System design, AI engineering, databases, networking, concurrency and more, written for engineers building real trading and fintech systems — part of the Algomi Suite.
Follow one school library's reservation app from a single server to forty schools: requirements, estimation, scaling, storage choices, replication, consistency, CAP/PACELC, and the hashing tricks behind large-scale systems. Every idea arrives because a real problem forces it. Guide 1 of 5.
Created 2026-09-15 · Updated 2026-10-15 · System Design
From one guesthouse in Goa to 80,000 hotels: how a booking system claims every night of a stay exactly once, keeps payment uncertainty away from inventory, and stops two guests winning the same room. Includes the three follow-up questions interviewers use to separate good answers from great ones.
Created 2026-09-16 · Updated 2026-10-15 · System Design
Follow Ananya and her father from Pune to Srinagar via Delhi, through a fog cancellation and an aircraft swap, to see how an airline system models dated flights, multi-leg bookings and disruptions as durable workflows instead of simple status edits.
Created 2026-09-16 · Updated 2026-10-15 · System Design
Every Monday at 08:00, 600 schools send progress reports to parents. One Monday some parents get two and some get none. Here is why a job definition, a scheduled run and an execution attempt must be three different records, and why leases don't erase duplicate effects.
Created 2026-09-16 · Updated 2026-10-15 · System Design
Follow Imran, a junior developer looking for his next job, through a LinkedIn-like network: how to model connections and follows, why search and feeds are projections, and how a hybrid fan-out keeps one famous post from flooding the system.
Created 2026-09-16 · Updated 2026-10-15 · System Design
Three zones don't help if they all depend on one shared database. Quorums, static stability, multi-region trade-offs, and why replication isn't a backup.
Created 2026-09-21 · Updated 2026-10-15 · System Design
