A principal engineer reached me via LinkedIn. I had a first interview with him and he explained me the role and the interviewing process (several rounds with different team members and "live coding" tests to assess data analysis and visualization skills).
The first technical test was a "live coding" one to asses my SQL and Javascript skills. Basic questions but I didn't do it quite well. After this, I didn't get any feedback nor follow up from the recruiter principal engineer.
I think that following up with candidates is key, specially after the effort that they might have put into preparing the interview. Months later, I was reached by another principal engineer for a similar position. Same behavior. After these experiences, I wouldn't like to apply again or work in Cisco.