Java on Android without the language features Kotlin has: threading, equality, resource handling, and interoperating with Kotlin.
Use when building Android UIs with Jetpack Compose, managing state with remember/mutableStateOf, or implementing declarative UI patterns.
Use when implementing async operations with Kotlin coroutines, Flow, StateFlow, or managing concurrency in Android apps.
The shape of the layer graph: which layers exist, which way dependencies point, and what each one may touch.
Talking to a server: client configuration, what comes back, what happens when it does not, and how a request is authorised.
Use this skill when capturing or analyzing Android Perfetto traces for app startup, UI jank, freezes, memory, CPU scheduling, binder IPC…
Runtime permissions: whether to ask at all, how to ask, and what the app does with every answer including the silent ones.
Material Design 3 and Android platform guidelines.
Keeping a secret on a device you do not control: key storage, backup, intents, and client-side checks that are signals rather than controls.
What makes a test able to fail for the right reason: the shape of the seam, the scheduler it runs on, and what an assertion is allowed to…
Use Android/Kotlin code as the source of truth and implement the equivalent feature in iOS/Swift.
The View system: layouts, adapters, RecyclerView, ViewBinding, and the seam where a ComposeView sits inside a View hierarchy.
Generates Angular code and provides architectural guidance.
Use when handling async operations in Angular applications with observables, operators, and subjects.
Use when building Angular 16+ applications requiring fine-grained reactive state management and zone-less change detection.
Use when implementing animations — AnimationPlayer, AnimationTree, blend trees, state machines, sprite animation, and code-driven animation
Handle Anthropic rate limits \u2014 understand tiers, implement backoff,\n\
Implement tool use (function calling) with Claude to let it execute
Quality gate for iterative coding work that prevents "code slop" — the measurable degradation (god-functions, copy-paste duplication…
Enforces professional, intentional development mindset on every web coding task — preventing AI slop, unplanned code, and amateur security…
Three.js asset loading - GLTF, textures, images, models, async patterns.