Full-Stack TypeScript/React Engineer

Job Description:We are seeking an elite, highly disciplined Full-Stack Software Engineer from Eastern Europe or Latin America to build a browser-optimized, single-screen financial data-modeling application called "The Quantitative Treasury Core." This tool is a vertical B2B utility designed for international startup founders to track, calculate, and visualize their corporate cash runway across volatile multi-currency contractor networks.This is a fixed-price project broken down into 3 clear, non-negotiable milestones managed by an independent creative director. We operate on a strict, fixed-price milestone matrix over a 6-to-8-week production timeline. We have zero tolerance for feature creep, uncoordinated asset additions, or schedule delays.Core Responsibilities:Backend Integration and Schema Setup: Configure input and transaction tables inside Supabase, map secure Row-Level Security (RLS) tokens to isolate user session states, and code serverless API fetch loops that connect directly to live Open Exchange Rates API web tokens.Frontend Dashboard and Data Visualization: Compile a clean, responsive, single-page user dashboard using React.js or Next.js with Tailwind CSS, styled strictly in a premium, minimalist dark mode aesthetic. Implement Recharts.js or Chart.js to render fluid, client-side vector trend lines showing corporate cash runway expiration nodes.Monetization Gatekeeper Integration: Embed a white-label access wrapper script (such as Outseta or Orchestra) to automatically lock data dashboard viewports behind a secure Stripe payment checkout portal.Technical Prerequisites:Advanced proficiency in TypeScript, React/Next.js, and Tailwind CSS.Documented experience building interactive data dashboards and integrating client-side JavaScript charting libraries without frame-rate lag.Proven experience with Supabase or PostgreSQL database architecture, specifically configuring strict Row-Level Security (RLS) policies using JSON Web Tokens (JWT).Mandatory use of Git/GitHub for version control and clean, type-safe, well-documented source code management.Hiring Screening Condition:To be considered for this project, you must include a direct link to a functioning HTML5 web application, data dashboard, or interactive financial utility you have personally compiled that operates smoothly inside a web browser. In your proposal, briefly state your exact technical approach to handling client-side multi-currency calculation arrays dynamically without triggering memory leaks or main-thread browser sluggishness.Generic, automated cover letters will be instantly archived and purged. We value absolute mathematical precision and clear code hygiene.