Low Level Design: User Feedback Service
6 min read What Is a User Feedback Service? A user feedback service collects structured and free-form feedback from users across product surfaces, […] Read article
System Design
System Design
Low Level Design: Speech-to-Text Service
7 min read What Is a Speech-to-Text Service? A speech-to-text (STT) service, also called automatic speech recognition (ASR), converts audio input into a Read article
System Design
Low Level Design: Multimodal Search Service
6 min read What Is a Multimodal Search Service? A multimodal search service allows users to search using multiple input modalities simultaneously or Read article
System Design
Low Level Design: LLM Gateway Service
7 min read What Is an LLM Gateway? An LLM gateway is a service layer that sits between your application and one or Read article
System Design
Low Level Design: RAG Pipeline Service
7 min read What Is a RAG Pipeline? Retrieval-Augmented Generation (RAG) is an architecture that improves LLM output quality by retrieving relevant documents Read article
System Design
Low Level Design: AI Content Safety Service
8 min read What Is an AI Content Safety Service? An AI content safety service filters and classifies text (and other modalities) produced Read article
System Design
Low Level Design: IoT Data Ingestion Service
6 min read Problem Statement Design a scalable IoT data ingestion service that handles millions of connected devices sending sensor readings, events, and Read article
System Design
Low Level Design: Telemetry Pipeline
6 min read Problem Statement Design a telemetry pipeline that collects metrics from thousands of services and infrastructure nodes, applies sampling and aggregation, Read article
System Design
Low Level Design: Document Management System
6 min read What Is a Document Management System? A document management system (DMS) stores, organizes, and retrieves files in a way that Read article
System Design
Low Level Design: Wiki Service
7 min read What Is a Wiki Service? A wiki service lets users create and edit interconnected pages in a structured knowledge base. Read article
System Design
Low Level Design: Mention and @Tagging Service
2 min read Mention service content See also: Meta Interview Guide 2026: Facebook, Instagram, WhatsApp Engineering See also: Netflix Interview Guide 2026: Streaming Read article
System Design
Low Level Design: User Follow / Subscribe Service
9 min read What Is a User Follow Service? A user follow (or subscribe) service manages directed relationships between users: when Alice follows Read article
System Design
Low Level Design: Voting and Reaction System
8 min read Problem Statement Design a voting and reaction system that allows users to upvote, downvote, or attach emoji reactions to content Read article
System Design
Low Level Design: Internationalization Service
8 min read Problem Statement Design an internationalization (i18n) service that allows a large multi-product platform to serve user-facing strings in dozens of Read article
System Design
Low Level Design: Access Review Service
9 min read Problem Statement Design an access review service that enables organizations to periodically certify user entitlements. The service must snapshot current Read article