Job Summary: Develop and maintain internal web applications for large-scale data processing, inventory control, and customs reporting, covering user interface, architecture, and database logic. Key Highlights: 1. Advanced proficiency in React.js and JavaScript/TypeScript. 2. Advanced level in PostgreSQL and relational database design. 3. Experience with complex algorithms for FIFO inventory and ERP/WMS systems. Develop, optimize, and maintain internal web applications focused on large-scale data processing, inventory control (FIFO engines), and generation of customs compliance reports. The candidate will be responsible for both the user interface and the architecture and logic within the database. Essential Technical Requirements The ideal candidate must demonstrate proven expertise in the following technologies within our ecosystem: * **Frontend (The Interface):** Advanced proficiency in **React.js** and **JavaScript / TypeScript**. Must be able to manage complex state (Context API, Hooks) and build dynamic interfaces for large data tables. * **Backend & Cloud:** Solid experience working with **Supabase** or Firebase. Must know how to implement authentication, Edge Functions (in Deno or Node.js), and consume RESTful APIs. * **Database (CRITICAL):** Advanced level in **PostgreSQL**. Must not only write basic queries but also master SQL function creation (RPCs), complex JOINs, aggregations, and relational database design. * **Data Processing:** Experience handling local files. Must know how to use file parsing libraries for CSV and Excel (e.g., PapaParse or SheetJS) directly in the browser. 2. Key Responsibilities * Design and implement complex business algorithms (e.g., FIFO inventory deduction engines, mathematical prorations, and "All-or-Nothing" validations). * Ensure input data cleanliness and standardization (date parsing, removal of special characters, strict format conversion). * Guarantee transactional data integrity, preventing negative balances or mismatches in traceability tables. * Securely connect the development environment with cloud-based production environments. Prior experience building modules for **ERP systems** (SAP, Oracle) or WMS (Warehouse Management Systems). * Basic understanding of inventory or logistics rules (receipts, shipments, remainders, bills of materials/BOMs). * Any prior exposure to international trade concepts, customs regulations, IMMEX rules, or Annex 24 will save months of learning curve. * **Relentless attention to detail:** In this sector, a decimal rounding error or misplaced comma in a customs document can invalidate an audit. Mathematical rigor is required. * **Algorithmic Thinking:** Ability to translate spoken business rules (e.g., *"Only use parts if the entry date precedes the exit date"*) into robust, unbreakable code. * **Assertive Communication:** Ability to explain complex technical issues to continuous improvement and operations leaders. Salary: $9,404.51 – $26,005.39 per month Work Location: On-site employment