Activity Feed System Low-Level Design
What is an Activity Feed? An activity feed shows users a chronological stream of events from people and things they […]
Design, System Design
Design, System Design
Bulk Operations System Low-Level Design
What is a Bulk Operations System? A bulk operations system allows users to create, update, or delete thousands of records
Design, System Design
Address Book System Low-Level Design
What is an Address Book System? An address book stores user contacts — names, emails, phones, addresses, and relationships. At
Design, System Design
Consent Management System Low-Level Design
What is Consent Management? Consent management records and enforces users’ privacy preferences: which data collection and processing activities they have
Design, System Design
Data Export Service Low-Level Design
What is a Data Export Service? A data export service allows users to download their data in bulk — CSV,
Design, System Design
API Versioning System Low-Level Design
Why API Versioning Matters APIs are contracts between your service and its consumers. Once published, breaking changes — renaming fields,
Design, System Design
Pagination System Low-Level Design
Why Pagination Design Matters Returning all results for a query — all 10 million orders, all 500K users — is
Design, System Design
Two-Factor Authentication System Low-Level Design
What is Two-Factor Authentication? Two-factor authentication (2FA) requires users to verify their identity with a second factor beyond their password:
Design, System Design
Subscription Management System Low-Level Design
What is Subscription Management? A subscription management system handles recurring billing: plans, upgrades/downgrades, trial periods, proration, cancellations, and payment retries.
Design, System Design
Data Masking System Low-Level Design
What is Data Masking? Data masking replaces sensitive data (PII, payment cards, SSNs) with realistic-but-fake values for use in non-production
Design, System Design
Search History System Low-Level Design
What is a Search History System? A search history system records a user’s past searches, enables autocomplete from personal history,
Design, System Design
Price Alert System Low-Level Design
What is a Price Alert System? A price alert system notifies users when a tracked item’s price drops below their
Design, System Design
User Onboarding Flow System Low-Level Design
What is an Onboarding Flow System? An onboarding flow guides new users through setup steps to reach the “aha moment”
Design, System Design
Geofencing System Low-Level Design
What is Geofencing? Geofencing defines virtual geographic boundaries (circles or polygons) and triggers actions when a tracked entity (user, vehicle,
Algorithms, Coding Interview Questions
Interval Algorithm Patterns for Coding Interviews
Why Interval Problems Matter in Interviews Interval problems appear in scheduling, calendar, and range queries — and in coding interviews