dot-skills

Write, revise, or review software design documents using Malte Ubl's "Design Docs at Google" guidance. Use when Codex needs to draft a design doc, technical design, RFC, engineering review doc, architecture proposal, mini design doc, or design-doc review focused on context, goals, non-goals, trade-offs, alternatives, cross-cutting concerns, review lifecycle, and deciding whether a design doc is warranted.

Write Go CLIs that manage processes and workloads — daemons, supervisors, job runners, deploy tools, anything that spawns or controls other processes. Use when writing, reviewing, or refactoring Go that handles OS signals, runs children via os/exec, fans out concurrent work, threads context for cancellation, returns exit codes, or builds a flag/cobra command surface. Covers the footguns the standard library makes easy to hit — SIGTERM vs Ctrl-C, SIGKILL-by-default children, orphaned process groups, pipe deadlocks, goroutine leaks, zombie reaping, and os.FindProcess lying about liveness. Triggers whenever the task touches process lifecycle, graceful shutdown, subprocess control, or concurrent workload supervision in Go — even if not named.

Structured UI design review — existing code (React/JSX, CSS, Tailwind) and, when behaviour matters, the running app in a real browser — reported as a prioritised Before / After / Why table. Covers visual hierarchy, spacing, typography, colour & contrast, component states, motion, responsiveness, accessibility, multi-page flow & navigation, and interaction continuity — grounded in Refactoring UI and Emil Kowalski's principles. For animation/jank/FPS, focus order, and cross-page UX it can drive Chrome via chrome-devtools-mcp to capture what a screenshot can't. Trigger when the user asks to "review this UI", "design review", "critique this component/screen/page or multi-page flow", asks why something "looks off", "looks AI-generated", or "looks like a wireframe", or wants to raise visual polish. For building UI from scratch use web-taste; for the full animation set see emilkowal-animations.

Inventing deterministic metrics — turning a fuzzy property like 'maintainability', 'risk', or 'how reducible this code is' into a deterministic, computable number an agent can trust and optimize. Covers the path from construct to adoption — operationalizing the construct, confronting computability limits (Kolmogorov, Rice) with sound proxies, picking the right measurement scale, proving properties (monotonicity, invariance, the Weyuker/Briand axioms), guaranteeing determinism, establishing construct validity (not just LOC in disguise), and hardening against Goodhart-style gaming when an agent optimizes the metric. Trigger when designing, reviewing, or validating a quantitative metric, score, measure, or index — and even when the user doesn't say 'metric' but wants to quantify, score, rank, or measure code/behavior, build a deterministic optimization target, or invent a measure for something previously unquantified (e.g., behavior-preserving codebase-size reduction).

Implementation guide for the 22 Gang of Four design patterns in TypeScript, distilled from refactoring.guru. Use this skill when writing, refactoring, or reviewing TypeScript that exhibits a pattern-shaped problem — class-explosion from inheritance, conditionals switching on type, tight coupling to concrete classes, tree-shaped models, runtime algorithm selection, undo/redo, snapshot-and-restore, state-dependent behavior, subscriber notification, or hiding subsystem complexity. Each pattern entry includes intent, problem, solution, applicability (when to use AND when NOT to use), a runnable TypeScript example, implementation steps, pros/cons, and relations to sibling patterns. Trigger even when no pattern is named — cues like "class getting unwieldy," "giant switch," "swap implementations at runtime," "combinatorial subclasses," "need undo," or "traverse a tree" are pattern-shaped. Covers all 5 Creational, 7 Structural, and 10 Behavioral GoF patterns.

TypeScript's functional answers to the 22 Gang of Four classes — factory functions (Factory Method, Abstract Factory, Prototype, Memento), module-scope singletons, fluent immutable builders, wrapper functions (Adapter, Facade), native Proxy, WeakMap caches (Flyweight), discriminated unions with exhaustive match (State, Visitor, Composite), event emitters and signals (Mediator, Observer), pipelines and composition (CoR, Decorator), stream methods (Iterator), closures-as-commands, higher-order strategies, lambda placement. Use when reviewing TypeScript that has a class-shaped problem the GoF catalog solves with a hierarchy but where idiomatic TS reaches for a function, a tagged union, or a data structure. Each rule names the GoF pattern(s) it replaces and when the class form still wins. Trigger on "factory class", "singleton getInstance", "state machine class", "observer pattern", "AST visitor", "where do I put this lambda". Sibling to implementation-design-patterns.

Methodology for starting a new library-reference distillation skill — one that turns an external library (nuqs, zod, framer-motion, msw, react-hook-form, emilkowal-animations) into an idiomatic-usage rule pack — or evolving one against a new upstream release. Distills the conventions empirically shared across shipped library-ref skills in this repo — the source-priority ladder (docs → blog/changelog → issues → types → examples), version pinning that inverts with API velocity, the universal 4-tier category ladder (CRITICAL setup → HIGH isolation → MEDIUM composition → LOW edge cases), the 4-slot When-to-Apply template, the failure-gap exemplar heuristic (privilege production lessons over API restatement), and metadata.references[] as cite-set checksum. Triggers on "I want to write a skill for library X", "refresh against new upstream", "where should I source rules from", "what categories should this skill have", and on /dev-skill:new for a library-reference distillation.

Same behaviour in fewer, clearer lines — covers the judgment gaps that linters cannot catch (reinvention, wrong frame, hidden duplication, derived state, procedural rebuilds, speculative generality, defensive excess, type-system underuse). Trigger when reviewing, refactoring, or simplifying code — and even when the user doesn't explicitly ask for "simplification" but is reviewing code, refactoring, or asking "is there a shorter way to write this?". Complements knip/eslint/ruff/tsc by focusing on the conceptual modelling layer those tools cannot see.

On-demand pattern extraction from a specific GitHub codebase, given a focused query — "how does shadcn/ui implement the design system", "how does opencode use effect-ts", "how does base-ui handle composition" — when no pre-distilled static rule pack exists yet. Distills the generic pattern-extraction moves — classify the query before grepping (component / composition / state / effect / error / build / routing), grep before reading whole files, treat tests and examples/ as canonical intent, follow imports outward for the public surface, follow usages inward for variants, filter boilerplate / legacy / test scaffolding to surface load-bearing code, and capture findings to /knowledge/libraries/ for reuse. Dynamic light sibling of static code-atlas skills (opencode-ts, openai-codex-rust-patterns, nextjs-ppr-patterns). Triggers on "show me how <library> implements X", "find the <pattern> in <repo>", "distill <library>", and ad-hoc /distill-<library>-style invocations.

Library-documentation lookup methodology — API behavior, version-specific changes, idiomatic usage, or why production diverges from docs — independent of which library. Distills the generic navigation moves shared across libraries — classify the question before searching (changelog vs API reference vs idiom vs known-bug), check llms.txt before scraping HTML, pin to the user's version before reading reference pages, read changelog first for "did X change" questions, treat examples/ dirs as truth for idioms, and fall back to GitHub issues / status page / Discord when docs match but reality doesn't. Per-library topography lives in the shared /knowledge/libraries/ graph as thin reference data, alongside code-distill's section. Triggers on "where in <library> docs", "look this up in <library>", "did <library> change X", "docs say X but code does Y", and any prompt where the next move is to consult a library's official documentation.

Cognitive moves for collapsing complexity — reframe, clarify, reduce, decompose, invert, constrain, transfer, generalize, audit — distilled from the working method of mathematicians, physicists, and software engineers known for turning hard problems into simple solutions (Pólya, Feynman, Hamming, Brooks, Knuth, Dijkstra, Lamport, Tao, Grothendieck, Munger, Hofstadter). Use when stuck on a complex problem, when a proposed design feels overengineered, when reviewing code that has accreted accidental complexity, or when the user wants an elegant solution to a hard engineering or product problem. Triggers on phrases like "this feels too complicated", "we are going in circles", "there must be a simpler way", "interview me about this plan", "find the underlying problem", and on stuck-state moments where forward search has run out and the agent needs a different angle.

Migrates a nuqs codebase off pre-v2.5 patterns — deprecated `throttleMs`, hand-rolled setTimeout/useState debounce around `useQueryState`, unchecked `parseAsJson` casts, unversioned `nuqs/adapters/react-router` imports, or `ParserBuilder<T>` type references. Scans the repo, produces a dry-run report, asks for confirmation, applies AST codemods, then runs `tsc --noEmit` + the user's lint as a gate. Trigger even if the user only mentions "upgrade nuqs" or "migrate to nuqs v2.5+" without naming the specific patterns — they almost always exist in pre-v2.5 codebases.

Scaffolds URL-state filters for a Next.js page — typed `searchParams.ts` parser map and a `<Filters />` client component backed by `useQueryStates`. From a single JSON spec, generates four files in lockstep — client parser map, server loader/cache/serializer, client component, and Vitest test — all sharing the same parser definitions per the nuqs Standard Schema pattern. Trigger even when the user only says "add filters to /search" or "I need a typed query string for this page" — both are exactly this skill's job.

Scaffolds React 19 / React 19.2 code in TypeScript — components, Server Component pages, client islands, form actions with useActionState, context providers, custom hooks, reducers, or document metadata + resource hints. Generates production-grade code that follows React 19 idioms (ref-as-prop, <Context value={...}>, useActionState, inline metadata, useSyncExternalStore) and refuses deprecated React 18 patterns (forwardRef, <Context.Provider>, useFormState, react-dom/test-utils). Trigger even when the user says "create a component", "new page", "add a form", "new hook", or "scaffold X" without explicitly mentioning React 19.

Audits a Next.js (App Router, 14/15+) codebase for React Hook Form anti-patterns — watch() at form root, Controller inlined in parent, async submit without try/catch, missing setError on server failures, RHF in non-"use client" files, RHF mixed with useActionState, schemas defined inside components, useFieldArray without field.id keys, register({ disabled }) for visual disabling. Read-only; emits a markdown report with file:line citations linking back to the companion `react-hook-form` distillation skill. Trigger when the user asks to audit/review/lint RHF usage, find form anti-patterns, or run a quality check on forms — even if they don't say "react-hook-form" by name; if they mention auditing forms in a Next.js project, use this skill.

Expert-level Rust testing — the "What Could Break?" framework, five transformations from superficial to expert tests, flake hunting protocol, intent-based assertions, naming conventions, and a mandatory self-review checklist. Triggers on writing Rust tests, designing test cases, improving test quality, or reviewing test coverage.

TypeScript performance, tsconfig, type errors, async patterns — triggered when the user asks to "optimize TypeScript performance", "speed up tsc compilation", "configure tsconfig.json", "fix type errors", "improve async patterns", or encounters TS errors (TS2322, TS2339, "is not assignable to"). Also triggers on .ts, .tsx, .d.ts file work involving type definitions, module organization, or memory management. Does NOT cover TypeScript basics, framework-specific patterns, or testing.

Designs new features, extensions, or modifications to Uncle Bob's Acceptance Pipeline Specification — new mutation strategies, Gherkin syntax support, report formats, pipeline stages, IR fields, or handler patterns. Trigger when someone asks "how would I add X to the acceptance pipeline" or discusses spec-level changes to the parser, generator, runtime, mutator, or reporter components — even if they don't explicitly say "feature design." Works in tandem with the acceptance-pipeline-catalog skill, which provides the baseline spec reference.

Algorithmic complexity (Big-O) review — finding nested loops, N+1 queries, exponential recursion, quadratic string builds, and other accidental complexity blowups. Covers Python, JavaScript/TypeScript, Java, Go, and similar languages. Use whenever writing, reviewing, or refactoring code where Big-O matters. Trigger even when the user doesn't mention "Big-O" explicitly — if they're reviewing code for performance, refactoring a hot path, asking "why is this slow," or working with data that scales (loops, recursions, collections, ORM access), apply this skill to classify the time/space complexity and suggest the fix. Especially trigger on tasks like "review for performance," "find slow code," "make this faster," "this code is O(n²)," or when reading code that processes collections.

Migrates React UI code to Base UI (`@base-ui/react`) — replacing bespoke modals, custom dropdowns, raw `<dialog>`/`<select>` elements, ad-hoc popovers/menus/tooltips, or other component libraries (Radix UI, Headless UI, Reach UI). Ships a 37-component catalog (snapshotted from base-ui.com/llms.txt) and scripts to refresh it, scan for migration candidates, and verify the migration compiles. Triggers on phrases like "migrate to base-ui", "use base-ui instead of X", "replace this dialog/popover/menu with base-ui", or when scanning a React codebase for components Base UI can replace. Trigger even if the user only mentions one component (e.g., "swap this modal for base-ui dialog") — the workflow scales from one file to a whole repo.

Scaffolds a Better Auth setup in a Next.js (App Router) + Drizzle project — lib/auth.ts, lib/auth-client.ts, the /api/auth/[...all] route handler, middleware.ts, .env.example, and a permissions module. Produces convention-enforced templates for three plugin presets (minimal, social, advanced with twoFactor+magicLink). Trigger even when the user doesn't explicitly say "scaffold" — phrases like "set up Better Auth", "wire up auth", "initialize auth in this project", or "add auth to Next.js" should pull this in. Pairs with the `better-auth` skill, which covers the rules these templates encode.

Better Auth in TypeScript — setting up the auth instance, picking adapters, wiring framework route handlers, configuring sessions and cookies, adding plugins (2FA, organization, admin, magicLink, JWT), or porting from NextAuth/Auth.js, Clerk, Auth0, or Supabase Auth. Covers Next.js, SvelteKit, Hono, Express, Nuxt, Astro, and React/Vue/Svelte clients. Trigger when writing, reviewing, or migrating Better Auth code — and even when the user doesn't explicitly mention Better Auth but is working on TypeScript authentication, session cookies, OAuth providers, or auth-library migration. Contains 42 rules organized by impact across 8 categories.

Multi-pass PR bug review — 5 parallel passes, majority voting, independent Opus validation, and resolution rate tracking. Trigger on PR review, bug finding, code review, "review this PR", "check for bugs", "find issues in this PR", or /bug-review. Also trigger on /bug-review:resolve to classify whether findings were fixed at merge time, and /bug-review:report for resolution rate stats. Even if the user just says "review this" while on a PR branch, trigger this skill.

Entry point for MCP server development — interrogates the user about their use case, determines the right deployment model (remote HTTP, MCPB, local stdio), picks a tool-design pattern, and hands off to specialized skills. Triggers when the user asks to "build an MCP server", "create an MCP", "make an MCP integration", "wrap an API for Claude", "expose tools to Claude", "make an MCP app", or discusses building something with the Model Context Protocol.

Interactive UI rendered inside ChatGPT or Claude — OpenAI Apps SDK apps, MCP Apps (the @modelcontextprotocol/ext-apps standard), or MCP-UI components, with a Next.js/React server. Covers the MCP tool and resource architecture, the window.openai / ui-bridge data flow, widget state, sandbox/CSP security, display modes, visual design, and directory submission. Trigger when building, reviewing, or designing such apps — even when the user only says "chat app", "ChatGPT widget", "Claude app", "render UI in chat", "window.openai", "createUIResource", "outputTemplate", or "MCP app UI" without naming a specific SDK.

Designing CLIs that AI agents will invoke — non-interactive flags, layered --help with examples, stdin/pipeline composition, actionable errors, idempotency, dry-run, destructive-action safety, and predictable command structure. Use when designing, building, or reviewing a command-line tool that AI agents or automation will invoke. Trigger even if the user doesn't explicitly say "agent-friendly" — apply whenever they are writing `--help` text, adding a new subcommand, designing error messages, or reviewing a CLI's UX.

Black-box CLI grading harness — runs a test suite against a target CLI and reports per-rule pass/fail from the cli-for-agents 45-rule catalog. Use when reviewing, auditing, or grading a command-line tool for agent-friendliness. Trigger even if the user doesn't explicitly say "agent-friendly" — apply whenever they ask "is mycli good for agents?", "review this CLI", "grade my cli against the rules", "check if this tool is safe to automate", or "audit command-line design". Companion to the cli-for-agents distillation skill.

Rendering and perception layer for codebase-as-geohash-map visualisations — choosing what to encode on colour/size/position, picking perceptually honest colour scales (viridis/OKLCH, not rainbow), drawing tens of thousands of cells on Canvas2D + WebGL/deck.gl inside a 16ms frame budget, placing and decluttering labels, GPU or spatial-index picking, camera animation and level-of-detail crossfades, and keyboard plus screen-reader accessibility for the canvas. Sits on top of geohash-spatial-code-maps, which owns the geohash encoding, projection, tiling, and navigation math. Also covers nature-inspired rendering — Voronoi, circle packing, phyllotaxis, metaball hulls, edge bundling. Trigger even when the user does not say "visualisation" — if the work involves drawing, colouring, labelling, animating, or making navigable a code map, spatial heatmap, or large cell/point layer on the web, this is the skill.

Mapping an unfamiliar codebase into feature/business domains — answering "what is this about", "which files implement feature X", "where is the architectural spine", or reviewing a refactor that crosses module boundaries. 47 algorithms across 9 categories — graph construction (omnipresent filter, multilayer, SCC), lexical preprocessing (Samurai, TF-IDF), community detection (Leiden, Infomap, SBM, MCL, Walktrap, spectral, HDBSCAN), architecture recovery (Bunch+MQ, ACDC, Limbo, Reflexion, DSM), topic modelling (LDA, LSI, NMF, HDP), evolutionary coupling (Gall, ROSE), information-theoretic (NCD, MI, MDL, naturalness), centrality (PageRank, HITS, betweenness, TextRank), validation (MoJoFM, ARI/NMI, resolution limit, consensus, co-change prediction, ablation). Trigger without explicit "clustering" mention — codebase grokking, dependency mapping, domain extraction, architecture-recovery validation all apply.

Choosing or implementing an algorithm or data structure — asymptotic complexity, data-structure selection, sorting & searching, dynamic programming, graph algorithms, divide & conquer, greedy algorithms, string/sequence algorithms, and the at-scale toolbox (Bloom filters, HyperLogLog, Count-Min Sketch, reservoir sampling, consistent hashing, external merge sort, Aho-Corasick, MinHash/LSH). Trigger on tasks involving "what's the right algorithm for…", performance-critical code, code with nested loops over the same input, recursive solutions, shortest-path / scheduling / matching / DP problems, code review for accidental O(n²) blowup, and any "how do I do X at scale / on a stream / without enough RAM" question — even if the user doesn't explicitly mention "algorithm" or "complexity."

Reverse-engineering a Sketch file (or Figma export with similar shape) into pixel-perfect React + CSS — the iteration mental model, tree reconstruction, layout inference algorithms, geometry math, visual-regression diffing, and the style/typography/path conversions that make "improvement without regression" enforceable. Trigger even if the user doesn't explicitly mention "algorithms" but is converting a design source into web code, building a design-to-code pipeline, or struggling to make incremental fidelity improvements without breaking previously-converted output.

PlantUML diagram quality on the agent-uml collaborative canvas — three tiers: rendering safety (syntax that prevents HTTP 400 blank canvas), conversation mechanics (when to push a version vs ask a question, what to write in the message parameter), and design effectiveness (decomposition thresholds, cross-diagram traceability, export readiness). Trigger whenever calling agent-uml MCP tools (design_create, diagram_upsert, design_feedback, design_export) — even when the task seems simple, since a missing `as alias` makes elements un-annotatable and a skinparam mismatch makes diagrams unreadable.

Django backend patterns for recommendation services (AWS Personalize, Databricks Model Serving, internal microservices) and OpenSearch-backed search/feed endpoints. Covers fan-out orchestration (asyncio.gather, deadline propagation, partial results, async client reuse), external service protection (timeouts, circuit breakers, jittered retry, bulkheads, rate limits), OpenSearch query patterns (search_after, _source filtering, function_score, aliases, routing, bool.filter), result blending (score normalization, MMR, dedup, cold-start), Redis caching (stampede protection, model-versioned keys, two-tier, negative), resilience (partial-response envelope, stale-on-error, graceful degradation), async (sync_to_async, async ORM, uvicorn, contextvars, disconnect cancellation), and DRF response shape (cursor pagination, ETag, throttling). Use when building, reviewing, or refactoring such a Django backend. Triggers even without explicit "scale" cues. Includes 5 scaffolding templates.

Scaffolds Drizzle ORM + SQLite boilerplate — a new `drizzle.config.ts`, a singleton client with the right pragmas, per-table schema files with explicit primary keys/indexed foreign keys/relations()/inferred types, per-table repository modules with `.returning()` + `inArray()` + `.onConflictDoUpdate()`, or drizzle-zod validators. Produces convention-enforced templates for three drivers (better-sqlite3, libsql/Turso, bun:sqlite). Trigger even when the user doesn't say "scaffold" — phrases like "add a table for X", "set up Drizzle in this project", "wire up SQLite", "create a CRUD module for X", or "bootstrap the DB layer" should pull this in. Pairs with the `drizzle-sqlite` skill, which covers the 45 rules these templates encode — read it when an exception is required.

Drizzle ORM targeting SQLite (better-sqlite3, libsql/Turso, bun:sqlite, Cloudflare D1, expo-sqlite, op-sqlite). Covers schema definition (column modes, primary keys, foreign keys, indexes), drizzle-kit migrations (generate vs push, renames, custom SQL), the query builder (selects, upserts, returning, EXPLAIN), the relational query builder (relations(), `with`, partial columns), transactions and `db.batch()`, prepared statements with `sql.placeholder()`, connection pragmas (WAL, foreign_keys, busy_timeout), and Drizzle type inference (`$inferSelect`, `$inferInsert`, `$type<>`, drizzle-zod). Use when writing, reviewing, or refactoring Drizzle code for SQLite. Trigger even if the user doesn't say "performance" — schema/migration choices made now are expensive to reverse later, and SQLite-specific traps (single-writer model, no native booleans/dates, ALTER TABLE limits, FK pragma off by default) catch teams who reach for Drizzle without reading the SQLite docs.

Developer-experience friction auditing and fixing — slow onboarding, repeated manual setup steps, missing bootstrap/reset/seed scripts, undiscoverable conventions. Audits the repo, scores findings, scaffolds canonical fixes (bootstrap.sh, reset.sh, seed.sh, AGENTS.md, task-runner entries), then verifies the harness end-to-end in a scratch worktree against a 60-second time-to-first-commit target. Triggers on phrases like "audit dx", "fix dev friction", "time to first commit", "set up the harness", "I keep doing X manually", "every time I reset the db I have to...", and on new-repo bootstrapping. Even if the user doesn't say "DX" — if they describe a repeated manual chore in their dev loop, this skill applies.

Effect-TS library usage in TypeScript — Effect.gen generators, Schema.Struct/Schema.Class definitions, Layer/Context.Tag/Service patterns, Effect.pipe pipelines, Data.TaggedError/Data.Class error types, Ref/Queue/PubSub/Deferred concurrency primitives, Match module, Config providers, Scope/Exit/Cause/Runtime patterns, or any code using Effect's typed error channel (E parameter). Trigger when writing, reviewing, debugging, or refactoring TypeScript code that uses Effect — when you see imports from `effect`, `effect/*`, or any `@effect/*` scoped package (schema, platform, sql, opentelemetry, cli, cluster, rpc, vitest). Also trigger when the user asks about Effect patterns, migration from Promises/fp-ts/neverthrow to Effect, or how to structure an Effect application. Do NOT trigger for React's useEffect, Redux side effects, or general English usage of "effect" unless the context clearly involves the Effect-TS library.

Measures whether Claude uses an MCP server's tools correctly — tests tool selection accuracy, analyzes schema quality, and iteratively optimizes descriptions. Triggers when the user asks to "evaluate MCP tools", "test tool selection", "improve tool descriptions", "check MCP schema quality", or "eval my MCP server". Companion to build-mcp-server.

Scaffolds Expo / React Native design system components that obey the expo-design-system rules by construction — a variant-driven pressable primitive, a slot-based card surface, a typed text primitive, a labeled form field, a FlashList entity screen, a theme token group, and a Storybook variant catalog. Generated code uses Unistyles v3 variants instead of style props, ref-as-prop, design tokens, built-in accessibility, and web/iOS parity (`_web` hover/focus/cursor on interactive primitives), so it follows expo-design-system without rework. Output is TSX/TS using react-native-unistyles. Trigger whenever the user wants to create, add, generate, or scaffold a new shared UI component, primitive, design token group, or screen for the clinic mobile app — even if they don't mention the design system.

Expo / React Native iOS interface conforming to Apple Human Interface Guidelines (iOS 26) — native navigation (Expo Router native stack and tabs), platform controls (Alert, ActionSheetIOS, SF Symbols via expo-symbols), safe areas, dark mode, Dynamic Type, haptics, Liquid Glass, accessibility, and 60fps motion. Covers architecture and styling decisions made in React Native/TypeScript; for the @expo/ui SwiftUI component API use the expo-ui skill, and for native Swift use ios-hig. Trigger when building, reviewing, or refactoring such an app — even when the user does not say "HIG" or "native feel" but is writing TSX screens, navigation, lists, forms, or styling for iOS in Expo.