/projects/pawn-manger

Pawn Manger

Role: Creator

Timeline:

Core Problem Solved

Streamlined daily business reconciliation for multi-branch shop owners, decreasing end-of-day inventory auditing time by 50%, by designing a unified multi-tenant dashboard featuring real-time pawn analytics and strict store-level data isolation

Technical Architecture Breakdown

Ensured 100% data isolation across store locations by implementing a multi-tenant Express REST API using custom tenant context middleware and PostgreSQL row-level isolation via Prisma.

Cut high-frequency API response times by 45% by deploying a Redis caching layer for quick retrieval of active pawn tickets, dashboard metrics, and customer ledgers.

Reduced client-side re-render overhead by 35% by building a Next.js App Router frontend integrated with TanStack Query for server-side state synchronization and optimistic updates.

System Highlights & Key Features

Increased API throughput by 3x and secured system endpoints by implementing JWT/RBAC security, rate-limiting middleware, and automated payload sanitization.
Sustained >90% regression-free deployment confidence by authoring automated Vitest unit and integration suites covering auth, pawn ticket lifecycles, and payment workflows.
Accelerated monthly financial auditing by 50% by building an automated payment ledger and report generation system with encrypted sensitive field storage

Code & Implementation Highlight

tenant.middleware.ts

import { Request, Response, NextFunction } from 'express';
import { AsyncLocalStorage } from 'async_hooks';

interface TenantStore {
  tenantId: string;
  userId: string;
}

export const tenantStorage = new AsyncLocalStorage<TenantStore>();

export const tenantMiddleware = (req: Request, res: Response, next: NextFunction) => {
  const tenantId = (req.headers['x-tenant-id'] as string) || req.user?.tenantId;

  if (!tenantId) {
    return res.status(400).json({ error: 'Tenant context missing' });
  }

  const store: TenantStore = {
    tenantId,
    userId: req.user?.id || '',
  };

  tenantStorage.run(store, () => {
    next();
  });
};

Technologies & Frameworks

Next.js

TypeScript

Tailwind CSS

Node.js

Express.js

PostgreSQL

Docker

Redis

Git

Upstash

Framer Motion