Engineering blog
How we build RatioAI.
Plain-language notes on the technology behind a private, browser-first PDF workspace.
Why your PDF never leaves your browser
Most PDF sites upload your file, process it somewhere, and send it back. We went the other way. Here is why, and what it took.
PrivacyArchitecture· 6 min readRead
Running a desktop-grade PDF engine in a browser tab
A quick tour of how we use WebAssembly to bring PDFium, the engine family behind Chromium's PDF viewer, into the RatioAI workspace.
WebAssemblyEngineering· 7 min readRead
Keeping the interface smooth when the file is huge
Why the page doesn't freeze while compressing a 500-page PDF, and how Web Workers and a little library called Comlink make that possible.
PerformanceEngineering· 5 min readRead
A workspace that survives a closed tab
How RatioAI keeps your current file and its version history on your own device, so reopening the tab brings everything back.
Local-firstStorage· 5 min readRead
Encryption, masking, and being honest about security
Why our redaction tool is called "Mask PDF (visual only)", and how password protection works when the whole thing happens in your browser.
SecurityProduct· 6 min readRead