Engineering deep-dives, privacy benchmarks, and platform updates from the builders of FolderBit.
September 2026•6 min read
Building an On-Device PDF Suite: Why We Moved Away from Server-Side Processing
Why stream multi-megabyte binary documents across public networks when modern browsers have WebAssembly and Web Workers? A deep dive into zero-upload document architecture.
High-Performance In-Browser OpenXML Processing: Compiling Word, Excel & PPTX in Pure TypeScript
How FolderBit eliminated server round-trips for Office conversions by reverse-engineering OpenXML namespaces and leveraging fflate for 8kB zero-dependency in-memory decompression.
Tamper-Evident Signatures: Cryptographic Hash Verification in Browser Memory
Building digital signature workflows with verifiable SHA-256 digest sealing, visual signature placement, and immutable audit logs without vendor lock-in.
Zero-Training AI Architecture: Keeping Document Workspaces Private
How FolderBit combines PostgreSQL Row-Level Security, ephemeral signed URLs, and cited Gemini extraction without ever contributing to public AI model training.
Offline-First PWA Engineering: Caching 31 PDF Utilities Without Active Connectivity
Using Service Workers, Stale-While-Revalidate caching, and isolated Web Workers to ensure full document productivity during flights and offline sessions.