Client-Side Data Management - I built a lightweight Java framework for Japan's "SI" projects (third attempt in 10 years) #009

Introduction If you've ever built business web applications, you've probably hit these friction points: Passing large amounts of data between pages — do you really need to round-trip through the server? Server-side sessions are heavy — resource consumption, session sharing across scaled-out nodes, timeout management… Building an auth system from scratch is painful — LDAP integration, JWT issuance and validation, deciding where to store tokens… This article presents three design approaches that tackle these problems together: Scoped browser storage — pass data between pages safely, organized by URL scope JS-variable session management — client-side session that auto-syncs with the server Transparent JWT authentication — LDAP + JWT with zero authentication code in business logic These three are tightly coupled. Combined, they produce a state where no auth or data-management code leaks into your business layer . 1. Scoped Browser Storage — Let Directory Structure Be Your Scope The Problem