Data Import Service Low-Level Design A data import service ingests user-supplied files into the system's database. The main challenges are: […]
Report Builder Low-Level Design A report builder lets non-engineers define, save, schedule, and share data reports without writing raw SQL.
Log Pipeline Low-Level Design A production log pipeline moves log data from every host and container to durable storage where
Error Tracking Service Low-Level Design An error tracking service answers two questions: “What broke?” and “Has it broken before?” It
Continuous Profiler Low-Level Design A continuous profiler measures where a production service spends CPU time without requiring code changes or
Object Types A version control system stores three object types in a content-addressed object store: Blob: raw file content. The
Rollout Schema A feature flag with gradual rollout has the following core fields: { flag_id: “checkout-v2”, rollout_plan: [ {percentage: 1,
Data Model: Shapes A whiteboard is a collection of shapes. Each shape is a flat record: { id: “uuid”, type:
Pull Request Model A pull request (PR) represents a request to merge a source branch into a target branch. Core
Escrow Model An escrow service acts as a neutral third party: the buyer transfers funds to a platform-controlled escrow account,
Tax Service Components A production tax calculation service has five distinct responsibilities: nexus determination (does the business owe tax in
Double-Entry Ledger A digital wallet service is built on a double-entry ledger: every financial event creates exactly two entries —
Ride Matching Service Low-Level Design A ride matching service connects riders with nearby drivers in real time, computing ETAs, scoring
Interview Scheduling System Low-Level Design An interview scheduling system matches candidate time preferences against interviewer availability, handles calendar integration, prevents
Knowledge Graph Overview A knowledge graph stores entities (people, organizations, places, events) and the typed relationships between them, enabling structured
