gRPC can use protocol buffers as both its Interface Definition Language (IDL) and as its underlying message interchange format

protocol buffers as the Interface Definition Language (IDL) for describing both the service interface and the structure of the payload messages.

This improves serialization and deserialization times

class Session extends Map { set(id, value) { if (typeof value === 'object') value = JSON.stringify(value); sessionStorage.setItem(id, value); } get(id) { const value = sessionStorage.getItem(id); try { return JSON.parse(value); } catch (e) { return value; } } }

When Sapper renders a page on the server, it will attempt to serialize the resolved value (using devalue) and include it on the page, so that the client doesn't also need to call preload upon initialization.