Author name: Admin

⏱ 3 min read Ephemeral State Design Typing state is intentionally ephemeral — stored only in Redis, never persisted to the database. There is […] Read article

⏱ 3 min read Graph-Based Recommendation Engine Model the recommendation problem as a graph: users and items are nodes, interactions are weighted edges. Graph Read article

⏱ 4 min read What Is an Anomaly Detection Service? An anomaly detection service monitors time-series metrics and identifies values that deviate significantly from Read article

⏱ 4 min read What Is a Rule Engine? A configurable rule engine evaluates business logic defined as structured data rather than code. Rules Read article

⏱ 3 min read WebAuthn / FIDO2 Overview Passkeys use public-key cryptography. The private key never leaves the device; the server stores only the Read article

⏱ 3 min read Data Model Closure table for efficient subtree queries: ThreadAncestor ( ancestor_id BIGINT, descendant_id BIGINT, depth INT, PRIMARY KEY (ancestor_id, descendant_id) Read article

⏱ 3 min read Schema Reaction ( entity_type VARCHAR(50), entity_id BIGINT, user_id BIGINT, reaction_type ENUM(‘like’,’love’,’haha’,’wow’,’sad’,’angry’), created_at TIMESTAMP, PRIMARY KEY (entity_type, entity_id, user_id) ) ReactionCount Read article

⏱ 3 min read PoP Selection and GeoDNS When a client issues a DNS query, GeoDNS maps the client IP to a geographic region Read article

⏱ 4 min read Geo-Fencing Service: Low Level Design Data Model GeoFence Table GeoFence ——– id BIGINT PK name VARCHAR(255) type ENUM(‘circle’,’polygon’) center_lat DOUBLE Read article

⏱ 3 min read Location Sharing Service: Low Level Design Data Model Location Table (Time-Series) Location ——– device_id BIGINT lat DOUBLE PRECISION lng DOUBLE Read article

⏱ 4 min read ETA Calculator Service: Low Level Design Road Network Graph Schema Node (Intersection) ——————- id BIGINT PK lat DOUBLE PRECISION lng Read article

⏱ 5 min read Overview A secrets manager provides secure storage, access control, and lifecycle management for credentials, API keys, and other sensitive values. Read article

⏱ 6 min read Overview An SSH key rotation service automates generation of new keypairs, distribution to all target hosts, a grace period with Read article

⏱ 4 min read CQRS Service: Low Level Design CQRS (Command Query Responsibility Segregation) separates the write model (commands) from the read model (queries), Read article

⏱ 5 min read Saga Orchestrator: Low Level Design The Saga pattern manages distributed transactions across microservices. An orchestrator-based saga drives each step sequentially Read article