LinkedIn Senior Software Developer interview questions

I had applied for the job from linkedin job postings. The recruiter called me and tooke 2 weeks to set up an phone interview. The interviewer, another senior software engineer, was prompt and described about the position and work done by his department. Asked question about algorithms and time complexity involved with with them and gave a problem and asked questions from my solution. It was hard to explain line by line program over the phone. This kind of interview should be done during 1:1 not over the phone