Feature Flag System Low-Level Design
7 min read Feature Flag System — Low-Level Design A feature flag system controls feature availability without code deployments. It enables gradual rollouts, […] Read article
System Design
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System Design
Learn to design scalable, reliable systems that handle millions of users. System design interviews test your ability to architect real-world applications, considering tradeoffs, scalability, and best practices.
Core Topics:
Scalability: Load balancing, horizontal vs vertical scaling
Storage: Databases (SQL vs NoSQL), caching (Redis, Memcached)
Reliability: Replication, failover, disaster recovery
Performance: CDNs, caching strategies, database indexing
Common Design Questions:
Design URL shortener (bit.ly)
Design rate limiter
Design Twitter/Instagram feed
Design messaging system (WhatsApp)
Design file storage (Dropbox)
Interview Level: Senior engineers (L5+) at FAANG companies. Requires 3-5+ years experience to tackle effectively.
Preparation: Study system design patterns, understand distributed systems fundamentals, and practice mock interviews.
System Design
Returns Portal System Low-Level Design
5 min read What is a Returns Portal? A returns portal allows customers to self-service returns and exchanges: select items to return, choose Read article
System Design
Storage Quota System Low-Level Design
5 min read What is a Storage Quota System? A storage quota system tracks and enforces per-user limits on resource consumption: disk storage Read article
System Design
Product Catalog System Low-Level Design
5 min read What is a Product Catalog System? A product catalog stores and serves product data: names, descriptions, images, prices, variants, and Read article
System Design
Activity Feed System Low-Level Design
5 min read What is an Activity Feed? An activity feed shows users a chronological stream of events from people and things they Read article
System Design
Follow System Low-Level Design
6 min read What is a Follow System? A follow system lets users subscribe to updates from other users or entities: follow a Read article
System Design
Bulk Operations System Low-Level Design
5 min read What is a Bulk Operations System? A bulk operations system allows users to create, update, or delete thousands of records Read article
System Design
Address Book System Low-Level Design
6 min read What is an Address Book System? An address book stores user contacts — names, emails, phones, addresses, and relationships. At Read article
System Design
Data Export Service Low-Level Design
5 min read What is a Data Export Service? A data export service allows users to download their data in bulk — CSV, Read article
System Design
Consent Management System Low-Level Design
6 min read What is Consent Management? Consent management records and enforces users’ privacy preferences: which data collection and processing activities they have Read article
System Design
Pagination System Low-Level Design
5 min read Why Pagination Design Matters Returning all results for a query — all 10 million orders, all 500K users — is Read article
System Design
API Versioning System Low-Level Design
5 min read Why API Versioning Matters APIs are contracts between your service and its consumers. Once published, breaking changes — renaming fields, Read article
System Design
Two-Factor Authentication System Low-Level Design
5 min read What is Two-Factor Authentication? Two-factor authentication (2FA) requires users to verify their identity with a second factor beyond their password: Read article
System Design
Subscription Management System Low-Level Design
6 min read What is Subscription Management? A subscription management system handles recurring billing: plans, upgrades/downgrades, trial periods, proration, cancellations, and payment retries. Read article
System Design
Search History System Low-Level Design
5 min read What is a Search History System? A search history system records a user’s past searches, enables autocomplete from personal history, Read article