⏱ 5 min read Personalization Engine Overview A personalization engine ranks content by predicted user interest rather than global popularity. The core idea: represent […] Read article

⏱ 6 min read Search Ranking System Overview A search ranking system determines the order in which retrieved documents are presented to users. The Read article

⏱ 5 min read Two-Token Architecture Modern authentication uses two token types with different properties: Access token: Short-lived (15 minutes), self-contained JWT. Resource servers Read article

⏱ 5 min read What a Session Store Does A session store maintains server-side state for authenticated users across stateless HTTP requests. The client Read article

⏱ 5 min read What an Orchestrator Does A data pipeline orchestrator schedules and executes directed acyclic graphs (DAGs) of computational tasks. Each DAG Read article

⏱ 5 min read What a Consensus Log Provides A consensus log is a fault-tolerant, ordered sequence of records that all nodes in a Read article

⏱ 5 min read Why PII Scrubbing Is Hard PII (Personally Identifiable Information) appears in many forms: structured fields like email addresses and SSNs, Read article

⏱ 4 min read The Distributed Scheduler Problem A scheduler that runs on a single node is a single point of failure. A scheduler Read article

⏱ 4 min read What a Response Cache Does A response cache sits in front of upstream services and stores HTTP responses so that Read article

⏱ 5 min read What a Request Router Does A request router sits between clients and backend services, inspecting each incoming HTTP request and Read article

⏱ 6 min read Dependency Graph Construction An asset pipeline must understand the relationships between source files to build correctly. The dependency graph is Read article

⏱ 5 min read Promotion Schema A discount engine evaluates active promotions against a cart and computes the final discounted price. The promotion schema Read article

⏱ 5 min read Coupon Schema A coupon service manages promotional codes that apply discounts to orders. The core schema: CREATE TABLE coupons ( Read article

⏱ 5 min read Core Schema The subscription manager tracks the relationship between users, plans, and billing periods. CREATE TABLE subscriptions ( subscription_id UUID Read article

⏱ 5 min read Preference Hierarchy A user preferences service must resolve the right value for any preference key given a user and device Read article