Frontend System Design Concepts

Evaluate the trade-offs between Client-Side Rendering (CSR), Server-Side Rendering (SSR), Static Site Generation (SSG), and Incremental Static Regeneration (ISR).

Explain the role and benefits of a Backend-for-Frontend (BFF) layer in decoupling the client from downstream services.

Compare the architectural trade-offs of a monolithic frontend versus a micro-frontends approach.

Explain the role of monorepos in managing large-scale frontend applications with shared code.

Design a shared dependency management strategy for a micro-frontends architecture.

Design a reusable and extensible UI component API.

Describe the five stages of atomic design (atoms, molecules, organisms, templates, and pages) as a scaling methodology.

Classify common UI elements (e.g., button, search form, page header) according to the atomic design methodology.

Design the API and structure of compound component patterns to manage complex UI logic.

Design an accessible component using ARIA attributes and keyboard navigation principles.

Differentiate between local, global, server, and URL state within a frontend application.

Design a normalized state shape for complex relational data on the client to ensure consistency and prevent duplication.

Evaluate the trade-offs of using centralized stores (e.g., Redux) versus context-based global state (e.g., React Context).

Design and explain the flow of optimistic UI updates for mutating data, including error handling and rollback.

Design a strategy for managing application state through URL query parameters for features like filtering and sorting.

Compare the use cases and trade-offs of REST, GraphQL, and tRPC for client-server communication.

Choose between Polling, Long Polling, Server-Sent Events, and WebSockets for delivering real-time updates.

Design a robust data fetching strategy incorporating request deduplication, client-side caching, and automated retries.

Compare the architectural and user experience trade-offs between pagination and infinite scrolling for large datasets.

Describe the sequence of steps in the browser's Critical Rendering Path and identify potential bottlenecks.

Define the Core Web Vitals (LCP, INP, CLS) and explain optimization strategies for each.

Apply code splitting and lazy loading techniques to reduce initial JavaScript payload size and improve TTI.

Explain the mechanism and trade-offs of list virtualization for rendering large data sets efficiently.

Design a strategy for improving perceived performance using skeleton loaders and placeholder content.

Choose the appropriate client-side storage mechanism (LocalStorage, SessionStorage, IndexedDB) based on specific data requirements.

Design a client-side database schema using IndexedDB for a data-heavy application.

Design a caching strategy using Service Workers for static assets and API responses to enable offline access.

Design a queueing mechanism using IndexedDB to store user actions performed while offline.

Design a process to detect network reconnection and trigger the replay of queued actions against the server.

Describe the core challenges of state management in real-time collaborative applications, such as concurrency and data consistency.

Explain the high-level concept of Conflict-Free Replicated Data Types (CRDTs) for eventual consistency.

Explain the high-level concept of Operational Transforms (OT) for maintaining strong consistency.

Compare the trade-offs between CRDTs and OT for resolving conflicts in collaborative editing.

Design a client-side state model for a collaborative feature, assuming a real-time communication channel exists.

Identify common XSS (Cross-Site Scripting) vulnerabilities and describe mitigation techniques.

Design a Content Security Policy (CSP) to prevent XSS and other injection attacks.

Explain the mechanism of CSRF (Cross-Site Request Forgery) and how to prevent it using tokens or SameSite cookies.

Explain how CORS (Cross-Origin Resource Sharing) works and specify the required server-side configuration for secure cross-origin access.

Diagram a secure authentication flow using JWTs and HttpOnly cookies, including login, token refresh, and logout.

Elicit functional and non-functional requirements for an e-commerce product page, focusing on SEO, performance, and scale.

Select and justify an appropriate rendering pattern (e.g., SSR, SSG) to optimize for SEO and perceived performance.

Design a faceted search and filtering interface with efficient URL state management.

Propose an image optimization and delivery strategy, including responsive images and lazy loading, for a product grid.

Design the state management strategy for a shopping cart feature, including optimistic updates when adding an item.

Gather requirements for a scalable real-time chat web application, including one-on-one and group chats.

Design the component tree for a chat interface, identifying the hierarchy and reusability of components.

Design a normalized client-side state shape for a chat application, considering messages, users, and channels.

Select and justify the network protocol for real-time message delivery and typing indicators.

Design a client-side storage schema and caching strategy for chat history using IndexedDB and Service Workers.

Propose a performance optimization technique (e.g., virtualization) for rendering large chat histories seamlessly.