1. Project Overview Vertex Suite is a Smart Business Management ERP built specifically for Indian SMBs. It replaces legacy tools and Excel-based workflows with a modern, cloud-based platform. The application is fully functional, deployed, and actively used by early adopters. We are looking for an experienced developer to join the project to fix known issues, optimize database performance, and build out new modules to scale it into a comprehensive SaaS product. 2. Tech Stack Requirements Frontend Framework: Next.js 14/15 (App Router) with TypeScript (Non-negotiable) Backend & Database: Supabase (PostgreSQL, Auth, Row Level Security, Edge Functions) Styling: Vanilla CSS (Custom design system with dark mode/glassmorphism—We do not use Tailwind) Components/Libraries: React hooks, Recharts (Area, Bar, Pie), custom browser-based PDF generation (lib/pdf.ts) Bonus Points if you have experience with: Indian GST/accounting software, WhatsApp API/Twilio integration, and Razorpay/PhonePe integrations. 3. Current State of the App The core infrastructure is live. You will be building on top of a solid foundation that already includes: Core Modules: GST-compliant Sales & Invoicing, Purchase Management, Multi-location Inventory, Cash Ledger, Expenses, and Customer Management. Enterprise Security: Multi-user roles (Owner, Manager, Staff), location-based UI isolation, and strict Row Level Security (RLS) policies at the database level. 4. Immediate Scope of Work (Phase A: Stabilization) Your first milestone will focus on stabilizing and polishing the existing codebase: TypeScript Cleanup: Resolve pre-existing type mismatches (e.g., missing properties on data interfaces). Mobile Responsiveness: Polish the mobile UI across the app (specifically layout adjustments and bottom navigation). Query Migration: Update legacy user_id database queries to business_id and ensure inventory UI properly filters by assigned locations. Performance Optimization: Conduct an EXPLAIN ANALYZE audit on Supabase RLS policies and add missing indexes to resolve slow queries under load. UX Improvements: Build and implement missing loading skeletons and global error boundary components. 5. Future Development Roadmap Upon successful completion of the stabilization phase, we will move into ongoing module development: Supplier Module: Dedicated vendor database, ledger, and outstanding payables tracking. GST & Filing: GSTR-1 JSON export matching the NIC portal, E-Invoice integration, and reconciliation. Payroll Module: Employee profiles, payslip PDF generation, and salary payment workflows. Analytics & BI: Product profitability, cash flow forecasts, and branch-vs-branch comparisons. SaaS Infrastructure: Subscription tier logic, usage limits, and payment gateway integration.