Build mobile-first layouts
Start from the smallest screen and the most constrained network. This forces prioritisation and reduces the temptation to ship heavy UI that only works well on desktop.
- Flexible grids and fluid type
- Thumb-friendly navigation and tap targets
- Clear primary calls to action without intrusive overlays
Set a performance budget from day one
Performance budgets keep teams honest. If a new feature breaks the budget, it must justify itself commercially, not aesthetically.
- Limit third-party scripts and tag sprawl
- Prefer CSS where possible over heavy JavaScript UI
- Use code splitting and defer non-critical bundles
Optimise interaction performance
Users feel slowness when the interface is unresponsive. That is often caused by long JavaScript tasks blocking the main thread.
- Keep filter interactions snappy
- Reduce layout shift caused by late-loading assets
- Audit scripts that run on every page
Images: serve the right size every time
- Responsive image sets and modern formats
- Compression and sensible lazy-loading
- Preload only what is genuinely critical
QA checklist that prevents ‘it works on my machine’
- Real device testing across iOS and Android
- Keyboard and accessibility checks on key journeys
- Slow network simulation to spot real-world pain
- Visual regression testing for key templates
Want a site that stays fast as it grows?
Sculpt Digital can help you build a performance-first approach across design, development, and tracking so speed and conversion do not degrade as features and marketing tags accumulate.