core▌

Deep Node.js internals expertise for native modules, V8 optimization, libuv diagnostics, and C++ addon development. \n \n Covers V8 garbage collection, hidden classes, JIT compilation, and deoptimization tracing; libuv event loop phases, thread pool tuning, and async I/O patterns \n Provides N-API and node-addon-api binding patterns, native memory management, and segfault debugging with gdb/lldb \n Includes build system guidance for node-gyp, gyp, ninja, and cross-platform compilation; diagnosti

Choose the right ASP.NET Core application model, compose the host and request pipeline correctly, and implement features in the framework style Microsoft documents today.

Schema definition, catalog creation, and spec streaming for AI-driven JSON rendering. \n \n Define schemas with typed specs and component catalogs using defineSchema and defineCatalog ; generate AI prompts automatically or with custom rules \n Support dynamic prop expressions including state binding ( $state , $bindState ), conditionals ( $cond ), templates, and computed functions \n Stream AI responses as JSONL patches using createSpecStreamCompiler for progressive spec building \n Built-in val

Expert Core Data guidance for iOS/macOS stack setup, migrations, threading, and CloudKit sync. \n \n Covers stack initialization, fetch requests, NSFetchedResultsController, saving patterns, and merge conflict resolution across all Core Data store types \n Provides threading best practices for both traditional perform/performAndWait patterns and Swift Concurrency with actors and Sendable types \n Includes batch operations, persistent history tracking, lightweight and staged migrations, and perfo

Foundation framework for building multi-step agents with built-in planning, memory, and skill delegation. \n \n Provides six core middleware options: task planning, filesystem context management, subagent delegation, persistent memory, human approval workflows, and on-demand skill loading \n Includes three always-present built-in tools: write_todos for task tracking, filesystem operations ( ls , read_file , write_file , edit_file , glob , grep ), and task for spawning specialized subagents \n Su

Opinionated, production-tested Playwright guidance — every pattern includes when (and when not) to use it.

Comprehensive guide to Core Spotlight framework and NSUserActivity for making app content discoverable in Spotlight search, enabling Siri predictions, and supporting Handoff. Core Spotlight directly indexes app content while NSUserActivity captures user engagement for prediction.

Core Data issues manifest as production crashes from schema mismatches, mysterious concurrency errors, performance degradation under load, and data corruption from unsafe migrations. Core principle 85% of Core Data problems stem from misunderstanding thread-confinement, schema migration requirements, and relationship query patterns—not Core Data defects.

Core principle: Core Data is a mature object graph and persistence framework. Use it when needing features SwiftData doesn't support, or when targeting older iOS versions.

Comprehensive API reference for modern Core Location (iOS 17+).