Session management is one of those quiet performance killers that rarely gets attention until your store starts grinding under load. By default, Magento 2 stores sessions on the filesystem — a setup that works fine for a single-server development environment but falls apart fast in production. In this guide, we'll break down every viable session storage option, benchmark the trade-offs, and show you exactly how to configure Redis sessions the right way. Why Session Storage Matters Every visitor to your Magento store — logged-in or guest — gets a session. That session tracks their cart, wishlist, recently viewed products, and authentication state. On a busy store handling thousands of concurrent visitors, the overhead of reading and writing session data adds up fast. The three main options are: Filesystem sessions — the default, stored in var/session/ Database sessions — stored in the session table in MySQL Redis sessions — stored in memory via a dedicated Redis instance Let's go through each in detail.…