Frontend Engineering

⏱ 3 min read Animations make products feel polished. Done badly, they make them feel slow. Frontend interviews increasingly ask about web animation — […] Read article

⏱ 3 min read Authentication is one of the most error-prone parts of a frontend application. Get it wrong and you have account takeover, Read article

⏱ 3 min read CSS layout in 2026 is a different world than the float-and-clearfix era. Grid, Flexbox, container queries, subgrid, and the upcoming Read article

⏱ 3 min read Form validation is one of the most common UI engineering problems. The 2026 ecosystem has consolidated around a small number Read article

⏱ 3 min read Frontend security is increasingly tested in senior interviews — not because every engineer should be a security specialist but because Read article

⏱ 3 min read Images are typically 50–80% of page weight. Optimizing them is the single highest-leverage performance work for most sites. Frontend interviews Read article

⏱ 4 min read “Build a search-as-you-type input” is one of the most common frontend interview questions. It tests whether you understand debouncing, race Read article

⏱ 4 min read “Build a virtualized autocomplete” extends the search-as-you-type question to handle large datasets — 10,000 countries, 100,000 products, or any list Read article

⏱ 3 min read “Build a date picker” or “build a calendar component” is a deceptively hard frontend interview question. It exposes whether you Read article

⏱ 3 min read React in 2026 is significantly different from React in 2020. Server Components, Suspense for data fetching, concurrent rendering, and useTransition Read article

⏱ 3 min read Frontend testing has matured significantly — Jest is sometimes replaced by Vitest, Cypress and Playwright dominate E2E, and React Testing Read article

⏱ 3 min read Micro-frontends are the architectural pattern of splitting a large web application into independently developed and deployed pieces. Module Federation (Webpack Read article

⏱ 2 min read “Build a Twitter timeline” is one of the most popular frontend system design questions at FAANG, mid-tier social, and FinTech Read article

⏱ 4 min read The Pinterest masonry grid is harder than it looks. Variable-height columns, infinite scroll, lazy-loaded images, no layout shift — all Read article

⏱ 2 min read “Build a checkout form like Stripe” is a beautifully focused frontend system design question. It touches PCI compliance, iframe sandboxing, Read article