Build a Multi-Tenant SaaS Trading Platform

I'm looking for an experienced full-stack developer to build a multi-tenant SaaS platform where users can sign up, onboard their own trading workspace, and execute or manage trades — all within a fully isolated, secure environment. Each tenant (user/business) gets their own dashboard with the ability to: • Run and manage trades (buy/sell orders, portfolio tracking) • View real-time or simulated market data • Monitor trade history, P&L, and performance analytics • Configure their own settings and preferences The platform should support: • Multi-tenancy architecture with strict data isolation between tenants • Authentication & authorization (OAuth2 / JWT) • Role-based access control (admin, trader, viewer) • Subscription billing integration (e.g. Stripe) • REST or GraphQL API backend • Clean, responsive dashboard UI Tech stack preference (open to suggestions): • Frontend: React.js or Next.js • Backend: Node.js / Python (Django or FastAPI) • Database: PostgreSQL with row-level security or schema-per-tenant • Hosting: AWS / GCP / Vercel Please share relevant past work, your proposed architecture, and a rough timeline with your bid. Fixed-price or milestone-based proposals preferred.