Have you shipped production features using Ruby on Rails and at least one modern frontend framework (Svelte/Vue/React) within the last 2 years?✱

Can you diagnose and fix N+1 queries, and implement pagination and appropriate DB indexing in Rails?✱

Have you designed and consumed JSON APIs end-to-end, including client-side handling of 4xx/5xx errors?✱

Do you routinely write request/model tests and use feature flags/rollback for safe releases?✱

Are you comfortable debugging browser issues (DevTools, network tab) and mapping Rails validation errors to UI forms?✱