Kolaborasi — Jersey Rental
Kolaborasi is an e-commerce platform for renting sports jerseys online, live at sewajersey.id. Built from one Flutter codebase running on Web, Android, and iOS, with a Firebase + Cloud Functions backend and online payments via Xendit. The system handles rental-period-based stock availability, automatic map-based delivery fee calculation, tiered discounts, vouchers, and 10-stage order status tracking.
Visit Website- Platform
- Web · Android · iOS
- Year
- 2026
- Industry
- Sports / Rental
- Role
- Full-cycle: architecture, Flutter frontend, Firebase & Cloud Functions backend
App screenshots
Click an image to zoom — swipe left/right to browse.
Key features
Real-time catalog & availability
Pick rental dates and the system hides products whose stock is fully booked for that period — computed from overlapping active order dates.
Per-day rental + minimum order
Day-based rentals with a 6-item minimum, size selection (S–4XL), and per-variant stock.
Automatic map-based delivery fees
Pick an address via Google Maps or GPS; distance is computed automatically (Haversine) and the fee = distance × per-km rate.
Pickup & delivery scheduling
Self-pickup or delivery options, with automatic checks against admin-blocked dates.
Tiered discounts & vouchers
Automatic discounts based on rental duration, plus a validated voucher system for price cuts or free delivery.
Xendit payments
Online payments via Virtual Account, e-wallets, QRIS, and credit cards — invoices created through Cloud Functions.
10-stage tracking
Order statuses from PENDING to COMPLETED, with a countdown payment-waiting page and status polling.
Full admin panel
Product & variant management, vouchers, discount tiers, delivery schedules, banners, and real-time store settings.
Technical highlights
The advanced parts behind the scenes that make this system run smoothly.
- Per-variant stock availability via date-range overlap checks, with an anti-race-condition token for repeated filter calls.
- Dynamic delivery fees: address geocoding → Haversine distance from store coordinates → per-km rate with a minimum fee.
- Cloud Functions: createXenditInvoice, xenditCallback, and releaseExpiredOrders to auto-release stock from expired orders.
- Per-period stock locks (lockStart/lockEnd) prevent double-booking the same jersey on overlapping dates.
- PENDING orders are deleted automatically if invoice creation fails — preventing ghost orders from holding stock.
- Responsive single codebase: two-column desktop layout, bottom-bar mobile checkout, with stock & price caching.
Tech stack
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