Very unprofessional behaviour. After you have invested so much time in attending the interviews and doing the coding assignment, they do not have a simple courtesy to share the feedback with you.
1) Telephonic Round(Simple question related work, node js etc)
2) offline coding - problem to for scrap a website.
3) Telephonic round- questions related to nodejs, architectute, rest apis etc
After these rounds, mailed the HR and CTO about interview feedback , to which they never replied back. Also tried to contact the HR over phone a couple times. Initially they will keep you hanging for 2-3 weeks and then later stop receiving your calls. Whether rejected/acepted, always share the feedback with a candidate who has invested hours with you.