Bulk ZIP Downloads Rebuilt: Reliability at Scale
How we rebuilt bulk ZIP downloads from the ground up — server-streaming, proper naming, browser download progress, and zero empty files.
Bizzi Team
Product & Engineering
On this page
Downloading an entire gallery or folder as a ZIP should just work. For creative teams delivering hundreds of files, broken downloads aren't acceptable. We spent a full engineering cycle rebuilding bulk ZIP from first principles.
The problem
Browser-built ZIPs via StreamSaver were producing empty files, truncated archives, and crswap artifacts blocked by X-Frame-Options. macOS Archive Utility threw Error 79 on corrupt streams. We needed server-streaming with proper byte timing.
What shipped
- ✓Server-streamed bulk ZIPs with response-driven download pipeline
- ✓Proper ZIP naming for galleries, subfolders, and bulk selections
- ✓Browser download progress in the Downloads UI
- ✓Eliminated empty ZIP files on failures and timing issues
- ✓Fixed nested folder ZIP exports with correct ancestor path stripping
- ✓Native browser downloads — no StreamSaver mitm iframes
Reliability as a brand promise
Download failures erode trust faster than missing features. Rebuilding ZIP delivery end-to-end demonstrates engineering discipline and respect for how clients actually receive finished work.