I applied online and passed the phone interview, then received a GitHub link for the restful API client. I took 6 hours or less to finish it with 1 year of experience in Golang, surely it is not difficult but the keys were to make the interviewer happy to test with it.
The interviewers spent times reviewing it and made concise comments. Seems that they are not satisfied with the unhappy test cases, the coverage of tests and the data type of returned error, and they may require not only the client from package "http".
The requirements of using `docker-compose up` to make the test are quite confusing and need some guess on understanding it.