ETF API Pagination and Caching Best Practices

ETF universes contain thousands of symbols. Return data with total, limit, and offset or a cursor. Apply a stable sort so users do not see duplicates or missing items while paging.

A cache key should include search text, filters, sort, limit, offset, and authorization scope when responses vary by plan. Short TTLs work for latest prices, while historical ranges can be cached much longer.

Debounce search, cancel stale requests, prevent duplicate load-more calls, and retain previous results during background refreshes. Show the market-data date rather than implying that a cached daily close is real time.