Core Entities Customer: customer_id, name, email, phone, default_address, stripe_customer_id. Restaurant: restaurant_id, name, address, location (lat/lng), cuisine_type, rating, is_open, prep_time_minutes, operating_hours. […]
The Sliding Window Pattern Sliding window optimizes O(n^2) brute-force approaches on contiguous subarrays/substrings to O(n). The key insight: instead of
Data Lake vs. Data Warehouse A data warehouse stores structured, schema-on-write data optimized for SQL analytics (Redshift, BigQuery, Snowflake). A
Why Bit Manipulation Matters in Interviews Bit manipulation problems test your understanding of how integers are represented in binary and
Core Entities User: user_id, email, name, quota_bytes, used_bytes. Document: document_id, owner_id, name, mime_type, current_version_id, parent_folder_id, is_deleted (soft delete), created_at, updated_at.
What is a Blockchain Explorer? A blockchain explorer is a read-only interface to blockchain data — like a search engine
Core Entities Issue: issue_id, project_id, title, description (rich text), type (BUG, FEATURE, TASK, EPIC), status, priority (P0-P3), assignee_id, reporter_id, parent_issue_id
Authorization Models ACL (Access Control List): per-resource list of who can do what. Simple but does not scale — updating
RTB Architecture Overview Real-Time Bidding is the programmatic ad auction system that runs every time a user loads a web
Core Entities Account: account_id, user_id, account_type (CASH, MARGIN), buying_power, portfolio_value, status. Order: order_id, account_id, symbol, side (BUY/SELL), type (MARKET, LIMIT,
State Machine DP Pattern State machine DP models problems as transitions between discrete states over a sequence. The key: define
ML Platform Architecture Overview An ML platform has three distinct phases: Feature Engineering — transform raw data into model-ready features
Core Entities Venue: venue_id, name, address, capacity, type (ARENA, CONFERENCE_CENTER, THEATER, OUTDOOR), facilities (JSON: {parking, catering, av_equipment}), timezone, is_active. Event:
When Does Greedy Work? A greedy algorithm makes the locally optimal choice at each step and hopes it leads to
Requirements An A/B testing platform enables product teams to run controlled experiments: show variant A to 50% of users and
