Serilog

Core Principles

1. Two-stage initialization — Create a bootstrap logger for startup, then replace it with the full logger after DI is ready. This captures startup errors that would otherwise be lost.
2. AddSerilog() over UseSerilog() — Use builder.Services.AddSerilog() (the modern API) instead of builder.Host.UseSerilog(). It integrates with DI services via ReadFrom.Services(services).
3. Message templates, not interpolation — {PropertyName} syntax creates structured data that can be queried. String interpolation ($"...") breaks structure and allocates even when the log level is disabled.
4. Configure via appsettings.json — Keep log levels, sinks, and overrides in configuration so they can change per environment without redeployment.

Patterns

Two-Stage Bootstrap Setup

using Serilog;