Ad inventory management involves the strategic oversight and sale of advertising spaces on digital platforms, such as websites and applications, to maximize revenue and ensure effective ad delivery. Publishers manage their ad inventory by categorizing ad slots, setting minimum prices, and using tools like ad servers or supply-side platforms to optimize performance and revenue. This process is crucial for balancing the supply and demand of ad space, improving user experience, and ensuring high-quality and relevant ads reach the target audience. Advertisers benefit from well-managed inventory through better ad placement and targeting, which can enhance engagement and return on investment. Different types of ad inventory, such as premium, remnant, direct-sold, programmatic, video, native, and mobile, each have distinct characteristics and pricing models, including CPM, CPC, CPA, CPV, flat rate, and vCPM, which influence how ads are bought and sold. The evolution of programmatic technology has introduced various methods for transactions between publishers and advertisers, including open RTB auctions, private marketplaces, and programmatic direct deals. Effective ad inventory management requires strategic approaches like yield management, header bidding, and leveraging automation tools, while also addressing challenges such as unsold inventory, real-time performance requirements, ad blockers, privacy regulations, and maintaining ad quality. Technologies like Aerospike can offer the speed and scalability needed for managing high-volume ad inventory, ensuring efficient and reliable ad serving in a rapidly evolving digital advertising landscape.