Author name: techinterview.org

⏱ 9 min read Spell Checker System: Overview A spell checker takes an input word (potentially misspelled) and returns a ranked list of correction […] Read article

⏱ 8 min read User Activity Feed: Overview A user activity feed aggregates events from actors a user follows and surfaces them in reverse-chronological Read article

⏱ 7 min read Recommendation Feedback Loop: Overview A recommendation system without a feedback loop becomes stale. The feedback loop closes the cycle: collect Read article

⏱ 8 min read Graph Search System: Overview A graph search system enables queries over a network of nodes and edges — users, connections, Read article

⏱ 8 min read What Is an ML Feature Store? An ML feature store is a centralized system for computing, storing, versioning, and serving Read article

⏱ 8 min read Why Model Serving Is Not Trivial Deploying a model to production is an engineering discipline separate from training one. A Read article

⏱ 9 min read Why a Dedicated Experiment Platform? A/B testing sounds simple — split users, measure a metric, run a t-test — but Read article

⏱ 8 min read A secrets management system stores, distributes, and rotates sensitive credentials — database passwords, API keys, TLS certificates, and cloud credentials Read article

⏱ 8 min read An audit logging system records every significant action in a platform — who did what to which resource, when, and Read article

⏱ 9 min read A health check service continuously probes every service in a platform, aggregates results through a dependency graph, classifies health states, Read article

⏱ 8 min read What Is an Address Validation Service? An address validation service takes raw user-entered address text, standardizes it to a canonical Read article

⏱ 7 min read What Is a Currency Conversion Service? A currency conversion service ingests exchange rates from multiple financial data providers, stores them Read article

⏱ 9 min read What Is a Service Mesh? A service mesh is an infrastructure layer that manages service-to-service communication in a microservices architecture. Read article

⏱ 7 min read What Is an Access Control List System? An Access Control List (ACL) system determines whether a given subject is permitted Read article

⏱ 8 min read What Is Collaborative Document Editing? Collaborative document editing allows multiple users to concurrently modify a shared document with changes reflected Read article