A plain-language walkthrough of the classic system-design interview moment. Covers: the big idea, why interviewers love the 100x question, what 100x really means in numbers, the four flavours of growth (more users, more requests, more data, wider geography), the mindset shift from correctness to survival, a reusable five-move loop, and…
A plain-language guide to capacity planning in system design: what it really is, why it matters, the different flavours of growth, the core ingredients (traffic, data, bandwidth), how to estimate traffic and peak load, storage and bandwidth, how to turn numbers into a server count, planning component by component, planning…
A plain-language guide to load balancers: what they really are, why they matter, how they work step by step, the two families of algorithms (static and dynamic) with every common variant, different kinds of traffic to balance, Layer 4 vs Layer 7, types by scope, hardware vs software, health checks…
A plain-language guide to the two most fundamental types of load balancing: static (round robin, weighted round robin, random, source IP hash, URL hash) and dynamic (least connections, weighted least connections, least response time, resource-based). Covers each algorithm in turn, a side-by-side comparison, real performance impact, how to choose between…
A plain-language, complete guide to horizontal partitioning: what it really is, how it differs from vertical partitioning, a short history, why it matters, the building blocks (parent table, partitions, partition key, routing logic), common strategies (range, hash, list, round-robin, composite, consistent hashing), how it relates to sharding, real-world uses, partition…
A plain-language, complete guide to back-of-the-envelope estimation: what it really is, where the name comes from, why interviewers care, the foundational numbers to keep in your back pocket, the common types of estimation, a repeatable six-step process, two fully worked examples (a photo-sharing app and a URL shortener), handy rules…
A plain-language, complete guide to idempotency in distributed systems: what it really is, where the idea comes from, why retries happen at all, how it maps onto HTTP methods and delivery guarantees, how idempotency keys work step by step, other complementary techniques, two fully worked examples (a coffee-shop payment and…
A plain-language, complete guide to microservices architecture: what it is, where the idea came from, how it compares to a monolith, the anatomy of a single microservice, how services communicate, how data is managed across many services, the supporting cast of gateways and meshes, security considerations, a fully worked bookstore…
A plain-language, complete guide to vertical partitioning: what it is, how it differs from horizontal partitioning, why it matters, the building blocks, its relationship to normalisation, two fully worked SQL examples, how the same idea appears in NoSQL, real-world uses, honest advantages and disadvantages, how to choose where to split,…
A friendly, complete guide to High-Level Design (HLD): what it is, why every serious project needs one, how it differs from LLD and requirements, the building blocks, quality goals, architecture styles, a worked food-delivery example, pitfalls to avoid, tools of the trade, HLD in interviews, and a reusable template.