I spent a chunk of time recently (10s of hours) doing dumb C# vs Go benchmarks - files and networking, and nothing worth taking seriously - just, usually the part about being IO-bound was true. C# is really impressive and was just a little slower with the best async solutions I could come up with. The machinery for async has overhead, so do Go routines and channels … the first-pass, not very performant code was just a little faster and IMHO clearer with Go (but I’m much better with Go /shrug).
It basically just loads a JSON file into memory then allows you to query the data with 2 API endpoints.