Got a call from consultant and he explain the process and where to apply. Once I applied I got the mail to do a project for API to exposed to call the spotify API with developer account. Question is someting like this - API Coding Challenge Summary A GraphQL API or REST API for storing metadata of music tracks to a Relational Database, fetching the metadata from the external Spotify REST API. Framework Requirements: Implement in GoLang using a lightweight node framework such (Gorilla Mux, Echo, or Gin etc.) We would like to see an ORM in place too (GORM) If you opt for REST API, then to document the API you are creating, feel free to use swagger.io. Code Challenge API Details: Write access: There should be a single endpoint to trigger for the creation of a track, which takes a single value “ISRC” o Input is just the ISRC An ISRC is more or less an identifier of a music track, see “Spotify API” section below o As soon as the call comes in, use the Spotify API to fetch the following metadata: Spotify Image URI Title Artist Name List o In case the SpotifyAPI returns multiple tracks take the track with highest popularity (an attribute in the Json) o Store the ISRC and the additional metadata into the DB No need to care about updating an already existing ISRC, skipping or give back an error is enough. o Read access: There should be 2 endpoints to retrieve metadata o By “ISRC”: single result o By “artist”: multiple results "like" search in the DB Multiple results (list/array) Spotify API Details: You should use this API to retrieve the metadata of a music track which is identified by an ISRC Create a developer account at Spotify As the challenge is about creating an API which uses the Spotify API, OAuth “Client Credentials Flow” should be used as authorization: o No need to cache the token for the code challenge, it's ok to grab it on each API Call o Spotify API Endpoints you might use Search for track using the title You can use that call to find out ISRCs of music tracks Some sample ISRC you can use: USVT10300001, USEE10001992, GBAYE0601498, USWB11403680, GBAYE0601477 o Feel free to search for some by yourself, the get by artists endpoint might need more tracks for the same artist Get track data by ISRC Details, Suggestions etc.: Choose a Database you are most productive with, MSSQL, MySQL, PostgreSQL whatever. You can choose the way you store the metadata. Normalized table(s), semistructured tables by storing JSON/Arrays into the DB, etc. o For the track->artist relation, it is not necessary to create a many-to-many relationship. A simple parent (track) -> child (artists) relation is enough The design of the REST API is up to you (GET/POST/PUT, query parameters, naming, hierarchy etc.) Of course, we want to see the API in action ;) o Use the client of your choice (Postman, Curl, Httpie etc.) to demo it How would you secure your API endpoints? (in detail) After that I got a call for the interview and where interviewer asked unrealistic question on the done assignment.