Nattapong Kaewseeiam

• Developed backend services covering wallet management, customer management, fare media/OBU management, toll transaction processing, billing, payment, auto-load, loyalty points, campaigns, reports, and back-office operations.
• Worked on multiple service components including E-Wallet API, Back-office API, and Toll Service.
• Implemented APIs for wallet, customer, fare media, transaction history, payment, bill, auto-load, inventory, onboarding, loyalty, campaign, report, and master data modules.
• Integrated event-driven processing using Kafka for toll transactions, settlement, monitoring, and balance-update flows.
• Implemented authentication, authorization, request validation, activity logging, and error handling for backend services.
• Supported report, CSV, and PDF generation for operational and back-office users.
• Used PostgreSQL for application data plus SQL scripts/migrations for database changes.
• Used Docker and GitLab CI / SAST pipeline configuration for deployment and code-quality workflows.

• Developed and maintained a platform for aircraft refueling workflows, flight schedules, dispatching, contracts, pricing, reconciliation, reporting, and operational dashboards.
• Worked on Core API, and the Integration API
• Built backend APIs with ASP.NET Core / .NET 8 for flight scheduling, dispatch management, vehicle/operator management, master data, contract/pricing, reconciliation, reports, and user administration.
• Developed the Integration API for external systems: master-data sync, transaction query APIs, delivery-receipt PDF generation, bulk ZIP generation, and publish-to-STG snapshot workflows.
• Developed real-time features with SignalR: dispatch boards, job boards, density updates, operator status, and time synchronization.
• Implemented authentication and authorization with Keycloak / JWT.
• Worked with SQL Server and Entity Framework Core for data access, migrations, and operational data management.
• Implemented Excel, CSV, and PDF export/reporting with document-generation libraries.
• Used Docker and GitHub Actions for build, publish, and container workflows.

• Built frontend features for a mobile WebView-based KPI tracking platform used inside Android and iOS apps.
• Built QR scanning and QR generation flows — camera permission handling, scan feedback, error states, and validation UI.
• Developed employee QR generation screens for unique employee-linked QR codes.
• Built KPI dashboard pages with summary views and table-based KPI data presentation.
• Developed role-based and business-unit-based frontend views for access-controlled dashboards.
• Built Branch2App landing pages and dashboard/table views segmented by role group and role branch.
• Delivered across multiple MVP phases: QR scanning, employee QR, dashboard, and Branch2App features.

• Developed frontend features for a financial savings-related digital service platform.
• Worked on user-facing pages for savings flows, saving history, transaction-based saving experiences, and financial-knowledge content.
• Built responsive Angular/TypeScript UI components for mobile and web usage.

• Developed features for the Mutual Fund Report system end to end.
• Built and maintained backend services using .NET, ASP.NET, and C#.
• Developed frontend screens using Angular and TypeScript.
• Worked with business requirements for mutual fund and investment reporting.
• Used Git for source control and team collaboration.

• Covered student profiles, parents, subjects, courses, course terms, class schedules, enrollments, and teacher assignments.
• Built attendance and check-in features, including status management and attendance printing.
• Developed billing modules: invoices, invoice approvals, installments, receipts, payment tracking, and payment reports.
• Built material/attachment management for books, course and student attachments, receipt attachments, videos, and learning resources.
• Developed calendar and schedule management using FullCalendar.
• Integrated LINE Messaging API and Dialogflow webhooks for student sign-in, timetable checking, and class check-in.
• Implemented JWT-based authentication and authorization for secure access control.
• Built RESTful APIs with ASP.NET Core and Entity Framework Core; real-time support via SignalR.
• Developed Angular/TypeScript screens for admin, student, course, payment, report, calendar, video, and tracking modules.
• Used Serilog for logging, Swagger for API docs, Docker + Caddy for deployment/reverse proxy, and Git + GitHub Actions for CI/CD.

Key projects

• Sales Tracking CRM — sales tracking and customer-related workflows.
• Document storage & borrowing/returning system — archive, storage, lending, returning, and search workflows.
• Cabinet resolution storage & search — storing, searching, and retrieving cabinet-resolution records.
• Document circulation system — electronic document circulation for university operations.
• Digital signature services — secure digital-signing workflows and service components.
• Activiti custom stencils — customized workflow stencils for business-specific workflow design.

Responsibilities

• Developed web applications with .NET, ASP.NET, C#, Angular, and TypeScript.
• Built backend APIs, frontend interfaces, and database integrations; auth via JWT.
• Worked with PostgreSQL and Entity Framework for data storage and access.
• Integrated document scanning via Dynamic Web TWAIN; built hybrid apps with Ionic Framework.
• Used Docker for deployment, GitHub Actions for CI/CD, and Serilog for logging and diagnostics.

• Developed Windows Forms applications for document receiving, registration, quality control, and storage administration.
• Built an ASP.NET Web Forms reporting system for tracking and reviewing document-processing status.
• Implemented insurance document workflows: receive, register, scan/OCR, QC, admin, and report modules.
• Worked with relational and NoSQL databases including MySQL and MongoDB; data access via Entity Framework.
• Implemented logging and troubleshooting support using NLog; Git for source control.