Performance is a feature (not a polish pass)

If the first interaction is slow, nothing else on the roadmap matters. Performance is product design: budgets, trade-offs and visible wins.

Budgets beat vibes

We set concrete targets — e.g. interaction P95, LCP, cold start — and measure on real mid-tier devices, not just the designer’s laptop.

Fast is a feeling. Budgets make that feeling shippable.

Where we look first

• Critical path: auth, home, money or booking actions
• Images, fonts and third-party scripts that tax every page
• API waterfalls that should be parallel or cached
• Offline / poor-network paths for mobile

Treat speed as a feature with an owner. Polish passes never catch what you never measured.