Representative embodiments described herein set forth techniques for optimizing large-scale deliveries of electronic Subscriber Identity Modules (eSIMs) to mobile devices. Specifically, instead of generating and assigning eSIMs when mobile devices are being activated—which can require significant processing overhead—eSIMs are pre-generated with a basic set of information, and are later-assigned to the mobile devices when they are activated. This can provide considerable benefits over conventional approaches that involve generating and assigning eSIMs during mobile device activation, especially when new mobile devices (e.g., smartphones, tablets, etc.) are being launched and a large number of eSIM assignment requests are to be fulfilled in an efficient manner.