Build CLI speed test tools using Go with speedtest.net protocol. Use when: (1) Building a new speed test CLI from scratch, (2) Implementing download/upload bandwidth testing, (3) Creating ping/latency measurement tools, (4) Building server discovery and selection systems, (5) Implementing rate calculation with EWMA, (6) Creating multi-format output formatters (JSON/CSV/human-readable), (7) Adding concurrent transfer testing with goroutines. Reference implementation in this project with full architecture, protocol documentation, and test patterns.
2026-01-27