#.Net Core

I added automated API snapshot tracking to a four-service .NET backend and watched GitHub Actions build times go from 3 minutes to over 12.

A production GitHub Actions pipeline for a multi-service .NET solution: build only what changed, cache NuGet and Docker layers, publish to GHCR, deploy over SSH with Compose, and the failure modes that cost the most time.

Run Vault in Docker, lock each .NET service down with AppRole and policies, layer KV secrets over appsettings.json with VaultSharp, issue short-lived database credentials, and fix the 403s and sealed-vault errors you will meet.

Spatial queries in .NET with PostGIS, Npgsql and NetTopologySuite: geometry vs geography, nearest-neighbour searches that use the index, geofencing, GeoJSON output, testing with Testcontainers and the errors you will hit.

Use Hazelcast distributed maps and .NET AsyncContext to coordinate operations across services. Covers locking, leader election and async patterns

Centralize routing, authentication and load balancing in .NET Core microservices with Ocelot API Gateway.

Extend ASP.NET Core Identity with custom UserManagers and SignInManagers to support multi-user-type authentication in a single app.

Set up Serilog and Seq in ASP.NET Core properly: bootstrap logging, request logging, trace correlation across services, destructuring, Seq queries, alerts, and the reasons your events never show up.

How TaskCompletionSource works, when to reach for it, and how to avoid the deadlocks and leaks it makes easy. Callbacks, events, request correlation and async primitives.