Development

Create responsive layouts using CSS Grid, Flexbox, media queries, and mobile-first design. Use when building adaptive interfaces that work across all devices.

Modernize and improve legacy codebases while maintaining functionality. Use when you need to refactor old code, reduce technical debt, modernize deprecated patterns, or improve code maintainability without breaking existing behavior.

Implement real-time functionality using WebSockets, Server-Sent Events (SSE), or long polling. Use when building chat applications, live dashboards, collaborative editing, notifications, or any feature requiring instant updates.

Implement reactive programming patterns using RxJS, streams, observables, and backpressure handling. Use when building event-driven UIs, handling async data streams, or managing complex data flows.

Build cross-platform mobile apps with React Native. Covers navigation with React Navigation, state management with Redux/Context API, API integration, and platform-specific features.

Design scalable React components using functional components, hooks, composition patterns, and TypeScript. Use when building reusable component libraries and maintainable UI systems.

Implement rate limiting, throttling, API quotas, and backpressure mechanisms to protect services from abuse and ensure fair resource usage. Use when building APIs, preventing DOS attacks, or managing system load.

Implement push notifications for iOS and Android. Covers Firebase Cloud Messaging, Apple Push Notification service, handling notifications, and backend integration.

Automate pull request workflows with templates, checklists, auto-merge rules, and review assignments. Reduce manual overhead and improve consistency.

Design property-based tests that verify code properties hold for all inputs using automatic test case generation. Use for property-based, QuickCheck, hypothesis testing, generative testing, and invariant verification.

Estimate project scope, timeline, and resource requirements using multiple estimation techniques including bottom-up, top-down, and analogous estimation methods for accurate project planning.

Build progressive web apps using service workers, web manifest, offline support, and installability. Use when creating app-like web experiences.

Profile application performance, identify bottlenecks, and optimize hot paths using CPU profiling, flame graphs, and benchmarking. Use when investigating performance issues or optimizing critical code paths.

Integrate multiple programming languages using FFI, native bindings, gRPC, or language bridges. Use when combining strengths of different languages or integrating legacy systems.

Design and execute performance tests to measure response times, throughput, and resource utilization. Use for performance test, load test, JMeter, k6, benchmark, latency testing, and scalability analysis.

Integrate payment gateways like Stripe, PayPal, and Square with backends for payment processing, subscription management, and webhook handling. Use when building e-commerce platforms, implementing billing systems, and handling payments securely.

Implement secure OAuth 2.0, OpenID Connect (OIDC), JWT authentication, and SSO integration. Use when building secure authentication systems for web and mobile applications.

Build production-ready Express.js servers with middleware, authentication, routing, and database integration. Use when creating REST APIs, managing requests/responses, implementing middleware chains, and handling server logic.

Debug network issues using browser tools and network analysis. Diagnose connection problems, latency, and data transmission issues.

Evaluate test suite quality by introducing code mutations and verifying tests catch them. Use for mutation testing, test quality, mutant detection, Stryker, PITest, and test effectiveness analysis.

Create and manage mocks, stubs, spies, and test doubles for isolating unit tests from external dependencies. Use for mock, stub, spy, test double, Mockito, Jest mocks, and dependency isolation.

Design for mobile devices first, then scale up to larger screens. Create responsive interfaces that work seamlessly across all device sizes.

Comprehensive mobile app testing strategies for iOS and Android. Covers unit tests, UI tests, integration tests, performance testing, and test automation with Detox, Appium, and XCTest.

Debug issues specific to mobile applications including platform-specific problems, device constraints, and connectivity issues.