What does it take to process one billion rows in Go? Not just fast
code — code you understand deeply enough to optimise, explain, and maintain in production.

In this hands-on tutorial, we use the 1 Billion Row Challenge (1BRC) as a performance playground. You'll instrument, profile, and optimise a real Go program — with guidance at every step.

You'll work through three iterations:
1. Naive implementation — correct, but slow
2. Optimised — fast, but can you prove why?
3. Observable — fast, instrumented, and fully explainable

Tools and techniques we'll cover:
- pprof: CPU, memory, goroutine, and block profiling
- go tool trace: concurrency and execution visibility
- go test -bench: disciplined benchmarking from the ground up
- Flamegraphs: visualise exactly where your CPU time goes
- OpenTelemetry Go SDK: custom spans to trace hot code paths

You'll leave with:
✓ A profiling-first performance mindset
✓ Hands-on experience with pprof, go tool trace, and OTel
✓ A reusable optimisation and benchmarking workflow
✓ Intuition for spotting bottlenecks before they hit production

Prerequisites: Basic Go knowledge.
Laptop with Go 1.22+ installed.