Currently, I am working for a digital advertising firm, where we used to take part in real-time advertising auctions, our system handles around 400k-500k bid-requests per second, our cloud servers (we call them bidder-servers) are constantly bidding & serving a large number of ads globally. We are using Redis as well for realtime data retrieval. It's really important for bidder-servers to read specific campaign data using geospatial query in real-time to identify the correct campaign's ad for the user. The speed and accuracy is also an important aspect.