The thread-per-core architecture is a design approach that aims to improve the efficiency and scalability of applications by utilizing modern hardware's capabilities. It involves running each core on a single thread, eliminating the need for threads and context switches. This approach can deliver significant performance gains, especially when combined with sharding, which allows multiple threads to work on different subsets of data. The Glommio library is an implementation of this architecture in Rust, designed to make it easy for developers to write efficient and scalable applications. It leverages Linux's io_uring API to manage I/O operations and provides a thread-per-core model that can run on Kubernetes infrastructure, with the potential to improve performance when matched with physical cores available in the underlying hardware.