Concepts in Frontend Dev, page 30
Angular JIT: Runtime Template Compilation
Angular JIT ships the compiler to the browser and builds components on the fly. It speeds up development rebuilds but pushes compilation cost to runtime. The footgun is deploying it to production, bloating bundles and hiding template errors until runtime.
BrowserRouter: Real URLs in React SPAs
BrowserRouter turns the address bar into a client-side navigation system, using real URLs without reloads. It is the default choice for SPAs that need shareable links.
Design System Guild: Cross-Team Governance
A design system guild lets squads co-own the system, not a central team alone. It scales when one team cannot cover every surface. The footgun is voluntary membership without decision rights; it devolves into a committee that ships nothing.
Virtual DOM Diffing: Minimal DOM Surgery
Virtual DOM diffing finds the smallest real DOM ops to sync a lightweight tree with new state. Frameworks batch rapid UI changes instead of repainting everything. The footgun is treating the diff as free; missing keys in lists force expensive reconciliation.
HashRouter: routing without server configuration
HashRouter traps routes after a # the server never sees, letting SPAs run on static hosts like GitHub Pages without rewrite rules. The tradeoff is ugly URLs and SEO blind spots since search engines may ignore whatever follows the hash.
Design System Roadmap: Sequence Adoption Over Completeness
A design system roadmap sequences components by business impact, not visual completeness, to stop teams rebuilding the same UI. Use it when multiple squads duplicate buttons and forms. The footgun is a perfect Figma library engineers never adopt.
Accessible React Forms: Labels, Focus, and Errors
Accessible React forms need real labels, keyboard focus, and error announcements, not just ARIA. Screen reader users must perceive inputs and validation without visual cues. The common footgun is placeholder text or divs instead of label elements with htmlFor.
Zustand Middleware: Intercept Every Set Call
Zustand middleware intercepts set calls to add logging, persistence, or devtools without touching business logic. Use it when updates need the same side effect, like localStorage sync.
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