Author name: techinterview.org

⏱ 9 min read Why CPU Cache Optimization Matters Modern CPUs execute instructions in nanoseconds, but DRAM access takes ~80ns — roughly 200 CPU […] Read article

⏱ 9 min read What Is a Virtual Memory System? Virtual memory is a foundational OS abstraction that gives each process the illusion of Read article

⏱ 9 min read Concurrency is one of the hardest problems in systems design. Bugs are non-deterministic, hard to reproduce, and can corrupt data Read article

⏱ 9 min read Relational databases have been the default choice for decades, and for good reason — SQL is powerful, ACID transactions are Read article

⏱ 7 min read Microservices migration is one of the most consequential architectural decisions an engineering organization makes. Done well, it unlocks team autonomy, Read article

⏱ 9 min read Compression is one of the highest-leverage primitives in systems design. It reduces storage cost, cuts network bandwidth, and often improves Read article

⏱ 9 min read A data warehouse is a system optimized for analytical queries across large volumes of historical data. Unlike transactional databases, warehouses Read article

⏱ 10 min read An audit log is an immutable, chronological record of every significant action taken in a system — who did what Read article

⏱ 9 min read DNS (Domain Name System) is the internet’s distributed directory service — it translates human-readable hostnames like www.example.com into IP addresses Read article

⏱ 8 min read Idempotency is the property that an operation produces the same result whether it is applied once or multiple times. In Read article

⏱ 7 min read What Is Role-Based Access Control (RBAC)? Role-Based Access Control (RBAC) is an authorization model where permissions are assigned to roles, Read article

⏱ 7 min read B-Tree Index Internals The B-tree (balanced tree) is the default index type in PostgreSQL, MySQL, and most relational databases. Understanding Read article

⏱ 8 min read The Three Pillars of Observability Observability is the ability to understand the internal state of a system from its external Read article

⏱ 7 min read Microservices decompose an application into independently deployable services. The communication layer between those services is where distributed systems complexity lives: Read article

⏱ 6 min read Dependency Injection (DI) is a design pattern and the practical application of the Dependency Inversion Principle (DIP). It removes hard-coded Read article