CO & EOT Mobile Application — API Development (Freelance) Laravel · PostgreSQL · Role-Based Auth · Financial Workflow Automation · Delivered ▸ Engineered a secure multi-role API backend (Client, Contractor, Consultant, Engineer) for a construction project management mobile app, supporting the full project lifecycle from initiation through closeout. ▸ Built a claims management engine with strict timeline validations (14/28/84-day rules), automated notice submissions, and engineer determination workflows — eliminating manual contract dispute processing. ▸ Delivered change order pipelines (major and minor variations) with approval gating, quotation generation, and completion confirmation, dynamically updating contract payment records on resolution. ▸ Implemented real-time push notifications and server-side API validation to enforce data integrity and keep mobile clients in sync with backend state changes.