Enterprise Operations Portal

A private operations platform used by staff across multiple locations every day, protected by Microsoft Entra ID single sign-on. It brings front-desk check-in, purchasing, IT support, shipping and live facility monitoring together in one portal, backed by a dedicated REST API and a companion product catalog.

The system is three ASP.NET Core applications on .NET 9 that share SQL Server: the staff portal, a REST API of around 40 endpoints that the portal, on-site controllers and IoT sensors all report to, and a role-based catalog. Staff actions reach the API through a server-side proxy, so API credentials never reach the browser, and each client authenticates with its own key.

Live dashboards stream industrial controller readings over SignalR, while an IoT hub pushes batched ESP32 sensor data to the API, which validates and de-duplicates it and flags sensors that drift out of range or stop reporting. Microsoft Graph turns messages sent to the help desk mailbox into tickets automatically, with a background service that keeps the webhook subscription renewed.

The most involved module is purchase approvals: routing driven by editable dollar thresholds and escalation rules, a live preview of who will need to approve, race-safe request numbering, an append-only audit trail, generated PDF records, and automatic filing of each request and its attachments to cloud storage with retry and backoff.

Performance work included a background-refreshed shipment cache that took one page from roughly 32 seconds to an instant read from memory, windowed chart queries in place of loading hundreds of thousands of rows, and trimming the published application from 120 MB to 39 MB.