How to handle multiple messages in single Request

Hi Experts,

I have the requirement like nearly 10K records coming in a single request and these records need to be processed and send the response after processing using the Rest API.But I am worried about Response time and performance

Ex: 10K stock levels coming In single request, so we want to validate and create these stock levels in hybris

Please guide me what is the best way to achieve this requirement with better performance and response time