App/Platform Engineer for Web App Refactoring

Refactor and extend our existing internal deal-management web app into a configurable, multi-tenant platform, built to designs we provide. Not a build-from-scratch — a working foundation exists. Feature-toggled multi-tenant architecture (one codebase serving a full internal version and a limited external version); the deal board, deal pages, custom fields, intake forms, portfolios, reports library, calculator, and outside-submitter portal; real-time updates; permissions enforced everywhere; the Convex app backend.