DTF Gangsheet Builder
Self-service print sheet builder with canvas auto-nesting, background removal, and automated fabrication file generation.
Private employer Details are sanitized; architecture and outcomes are described without proprietary identifiers.
- Role
- Full Stack Developer
- Year
- 2026
- Category
- Full Stack Software Dev
About This Project
Engineered a wholesale customer-facing gangsheet builder for DTF and UV DTF transfer orders. Customers upload artwork, size quantities, auto-nest images on a growing sheet in the browser, and submit fabrication-ready orders without manual back-and-forth. The system persists orders to IBM i, generates high-resolution print files through an external compositing service, and supports reordering past submissions with print-file reuse when layouts are unchanged.
Engineering Deep Dive
How a self-service gangsheet builder packs customer artwork with 2D bin packing in the browser, then turns submitted layouts into fabrication-ready print files through an asynchronous compositing pipeline.
Read the engineering deep diveTechnologies Used
Engineering Challenges
01
Browser-Based Nesting
Implemented rectangle-based 2D bin packing with rotation scoring, free-space splitting, and sheet height growth in 12-inch increments when images no longer fit, with live pricing refresh as layout changes.
02
Hybrid Print Pipeline
Kept pixel compositing on a Linux API while IBM i handled order persistence and business rules, including sync jobs for small orders and a background worker with status polling for large print files.
03
Preview vs Artwork Guardrails
Prevented full sheet previews and fabrication PDF URLs from being placed back on the canvas as customer artwork, avoiding corrupt layouts and invalid reorders.
04
Background Removal Flow
Integrated a manual erase/restore editor so edited PNG assets re-enter the same selected-images pipeline as uploads and library picks.
Technical Highlights
Placement Snapshots: Captured final canvas placements at submit, redrew without borders at print DPI, and sent structured placement data to the compositing API for PDF/PNG output.
Async Job Lifecycle: Queued print generation before an order existed, linked jobs after save, and handled worker completion whether it finished before or after the order record was written.
Draft Persistence: Stored full builder state in localStorage and serialized order JSON in DB2, including placements, DPI warnings, print metadata, and reorder flags for long-session recovery.
Reorder Optimization: Detected unchanged reorders and reused existing print files instead of triggering expensive regeneration.
Business Logic
Customer Self-Service: Wholesale buyers lay out gangsheets, choose DTF or UV DTF pricing, and submit orders with confirmation email and internal fabrication notification.
Production Handoff: Automated high-resolution print file generation replaced manual coordination between sales and the shop floor.
Repeat Orders: Past-order reload and print-file reuse reduced turnaround for repeat buyers and lowered compute cost on identical layouts.
Quality Guardrails: DPI and dimension warnings, plus page-break validation, caught bad artwork before compositing ran.