Post

Transactional Outbox Pattern: Keeping the Database and Broker in Sync

Doosan published on July 09, 2026

14 min, 2658 words

Categories: post

Tags: RabbitMQ MassTransit outbox messaging EF Core distributed systems

Understanding IdentityServer UserClaims: The Difference Between User, Identity Resource, and API Resource

Doosan published on July 06, 2026

17 min, 3313 words

Categories: post

Tags: C# ASP.NET Core IdentityServer OAuth 2.0 OpenID Connect Claims

Understanding ASP.NET Core Identity, OpenIddict, and Claims Authentication

Doosan published on July 04, 2026

15 min, 2954 words

Categories: post

Tags: C# ASP.NET Core Identity OpenIddict OAuth 2.0 OpenID Connect

The Webhook Died During the Handshake: Debugging ERR_TLS_CERT_ALTNAME_INVALID

Doosan published on June 22, 2026

4 min, 785 words

Categories: post

Tags: tls ssl certificate webhook dns debugging

First Declarer Wins — Debugging RabbitMQ Exchange State Drift

Doosan published on June 22, 2026

7 min, 1368 words

Categories: post

Tags: RabbitMQ MassTransit debugging messaging

Using two GitHub accounts with SSH on one machine (work + personal)

Doosan published on June 17, 2026

6 min, 1004 words

Categories: post

Tags: git ssh github command

Docker Components and Layers: docker, dockerd, containerd, runc, Colima, Lima

Doosan published on June 17, 2026

5 min, 973 words

Categories: post

Tags: docker colima lima containerd

Layer 1 — docker CLI (Client)

Doosan published on June 17, 2026

4 min, 775 words

Categories: post

Tags: docker cli layers

Layer 2 — dockerd (Daemon / API Server)

Doosan published on June 17, 2026

5 min, 837 words

Categories: post

Tags: docker dockerd daemon layers

Layer 3 — containerd (Container Runtime)

Doosan published on June 17, 2026

5 min, 837 words

Categories: post

Tags: docker containerd runtime layers