Architecture is the set of decisions that feel permanent after six months. An honest tour of monolith, layered, modular monolith, SOA, microservices and event-driven options: what each really costs and why the modular monolith deserves more attention than it gets.
AI agent architecture comes down to three strategies: single agent, sequential, and parallel. When one big prompt loses the plot, how sequential chains buy reliability, where parallel agents crush latency, and the pitfalls of each before you commit.
Zanzibar is how Google authorises billions of shared resources across Drive, YouTube and Calendar. A look at its relationship-based data model, the new enemy problem that forces strict consistency, and the Leopard system that keeps checks fast.
Ruby modules often beat classes for service objects: why a shell class like PasswordResetInitiator is procedural code in disguise, using a module as a toolbox, mixins instead of artificial inheritance, and Data objects for tidy parameters.
Event sourcing meets GDPR the moment a user asks to be forgotten and your log is append-only. Crypto-shredding is the elegant answer: encrypt personal data per user, delete the key, and design system boundaries so backups and read models forget too.
Business archetypes prove your 'unique' domain is usually a store selling something unusual. Map complex requirements onto universal building blocks: product catalogue, orders, entitlements, inventory for services, party and billing, and stop reinventing the wheel.
Pseudo-modularity looks like clean folders and rots underneath: a change in Products breaks Inventory tests and blocks three teams. Why noun-driven modules and a shared database create facade modularity, and what real module boundaries look like.
Party archetype fixes the 120-column User god object: model people and companies as parties, roles as context instead of identity, and relationships as first-class entities, so a customer who becomes a B2B partner no longer needs an is_partner flag and prayer.
CUPID challenges SOLID with properties instead of rules: composable, Unix philosophy, predictable, idiomatic, domain-based. Where the decades-old principles show their age in the cloud era, what 'joyful software' means, and whether SOLID is really done.
Sidekiq capsules let you give each queue its own concurrency, so photo processing stops clogging urgent jobs and API calls stay under rate limits. A three-step setup: configure the capsule, assign the job, and call it, with configuration examples.
Siamese twin modules force a change in one place to ripple into another. How domain leakage and state-transfer events create a distributed monolith, and how contextual modularization with the right communication patterns cuts the connection, without cargo cult.
PostgreSQL database size checks in a few simple SQL queries: list all databases with pg_database and pg_size_pretty, then break down the biggest tables in a schema, indexes included. Spot what eats disk space before it slows backups and raises infrastructure costs.
Slow SQL queries in Rails can be caught in development, before they become production fires. Using ActiveSupport::Notifications and the sql.active_record event, you build a small performance guard that logs every query above a time threshold straight to your console.
Deprecation lets you remove old Rails code without breaking teammates' apps overnight. A practical look at ActiveSupport::Deprecation: why sudden deletes hurt, how to warn about methods scheduled for removal, and how to phase out code in a civilized way.
Sending large files through Rails wastes memory and blocks app workers. X-Sendfile hands the transfer to NGINX while Rails keeps authentication and caching: server configuration, cache headers, testing in development, other HTTP servers, and a complete example.
PostgreSQL trigram similarity finds records despite typos: enable pg_trgm, run similarity queries from Rails, tune the threshold, order results by score, and wrap it all in a reusable scope. Great for fuzzy search and duplicate detection without external tools.
Rails console sandbox mode wraps every database operation in a transaction and rolls it all back on exit, so you can experiment safely. How to launch it, plus the traps: database locking, non-rollbackable operations, and why production use still needs care.
Legacy services with mismatched method names (validate, execute!, run!) can be unified with Ruby method objects. How to build one dispatcher that calls the right method on each class, why it beats conditionals, and what it does for readability.
Rails read and write databases in practice: configure a primary and replica in database.yml, enable automatic connection switching, update ApplicationRecord, and handle the replication challenges that come with splitting the load.
Creating rake tasks and passing arguments, four ways: the default bracket syntax, OptParse, raw ARGV, and Linux-style flags, plus namespaces and prerequisites for organizing tasks in a Rails app, each with a working example.
Three cases where React's useState is unnecessary: read inputs with useRef, submit forms with the FormData pattern, and keep state in the URL with useSearchParams. Code snippets show each alternative and when it beats state.
Simplifying complicated TypeScript with the KISS principle: refactoring examples show when explicit types improve a simple function and when clever type gymnastics make code harder to review, test, and maintain.
Blocking bots and attackers by request URL instead of IP: how the url_ban_list gem, born from three years of honeypot observations, recognizes malicious scan paths in your Ruby app and bans the clients requesting them.