With hundred to crores of products listed on a platform, search is very important. Users search with product related tags (including name) to find relevant products. Search criteria and logic should be efficient enough to return relevant information quickly. There could be various search criteria parameters that can be implemented. These could be user based and system based. User based would be where user selects some pre-defined criteria like attributes. Attributes could be colour, size, brand, specification etc. System based could be tag. When user types some term then system should be able to match words from terms with tags and search accordingly.
When user is searching for a product in a category then search criteria attributes should be shown accordingly. This would make user to pick relevant and more precise criteria only. Count of results (products) should be shown with search criteria individual item after user applies a criteria.