Garage Surf Market (GS Market)
A full-stack, enterprise-grade vintage apparel e-commerce marketplace featuring multi-channel payments, real-time logistics, interactive SVG garment measurements, price negotiations, and a loyalty points rewards engine.
Garage Surf Market (GS Market) is an enterprise-scale full-stack vintage apparel e-commerce platform built as a modern monorepo. It bridges high-converting retail UX for international buyers with a comprehensive back-office operations suite for store administrators.
The platform was engineered from the ground up to solve complex fashion retail problems: vintage apparel sizing uncertainty through interactive SVG measurement diagrams, cross-border payment flexibility (Midtrans automated gateway paired with manual international Wise wire transfers), dual-tier domestic and global courier integration with live tracking, and an idempotent loyalty reward points engine.
The Problem
Vintage and curated apparel commerce faces unique operational hurdles: inconsistent vintage sizing leading to buyer hesitation, fragmented domestic and international logistics, the need for two-way price negotiations ('Make an Offer'), and maintaining fraud-resistant inventory reservation for one-of-a-kind items.
The Solution
An end-to-end, high-performance monorepo application separating the customer storefront, admin dashboard, high-throughput REST API, and transactional database layer. Equipped with interactive vector sizing guides, multi-gateway checkout, automated courier rate calculation with 17TRACK syncing, real-time counter-offer negotiations, and a configurable loyalty points engine.
Tech Stack
Project Preview
Key Features
Interactive SVG Garment Measurements: dynamic vector schematics for tops, bottoms, and outerwear with instant cm/inch conversion
Dual-Gateway Checkout: automated Midtrans payments (dynamic QRIS, Virtual Accounts, 3DS Credit Cards) + Wise international transfers with in-browser image compression
Advanced Shipping & Tracking: real-time Biteship courier rates for domestic delivery, custom international shipping tables, and 17TRACK automated waybill tracking
Interactive 'Make an Offer' Negotiation Engine: two-way counter-offer workflow with time-limited windows and status state machines
Loyalty Points & Voucher Rewards: spend-to-earn point generation upon order settlement, voucher redemption catalog, and fraud-resistant single-active-voucher constraints
Printable Vector Invoices: client-side A4 PDF tax invoice generation with jsPDF, official branding, and itemized deductions
Comprehensive Admin Management: full inventory CRUD, UploadThing multi-image uploads, order fulfillment with shipping label printing, customer CRM, and review moderation
Enterprise Security: Better-Auth session management, Google OAuth, role-based access control, strict CORS, and multi-tier rate limiting
Challenges
- Architecting a scalable monorepo separating storefront (Next.js 15 App Router), admin portal, and backend API (Hono) while sharing type-safe Zod validation schemas and financial utilities
- Preventing race conditions and stock inconsistencies on rare one-of-a-kind (1-of-1) vintage items during high-concurrency checkout and payment webhook reconciliation
- Decomposing complex multi-thousand line legacy monoliths into single-responsibility custom hooks, isolated subcomponents, and testable sub-routers without breaking user flows
- Building an accessible, dual-unit (inches/cm) garment measurement visualization that dynamically detects apparel categories (tops, bottoms, outerwear)
What I Learned
- Deep mastery of modern monorepo engineering with Turborepo, pnpm workspaces, and shared Drizzle ORM database schemas
- Designing resilient payment state machines that gracefully handle webhooks, timeouts, idempotent operations, and manual proof validations
- Implementing performance-first UI patterns: Core Web Vitals optimization, zero hydration mismatch, and accessible WCAG AA standards