This is part three in a series where I learn OpenTelemetry (OTEL) from scratch. If you haven't yet seen them yet, part 1 is about setting up auto-instrumented tracing for Node.js and part 2 is where I initially implemented the OTEL collector. Today we are going to begin experimenting with sampling. We need to sample traces because we capture so much data! It would be impractical to process and store it all (in most cases).