The interview process was thorough but not so onerous like other hi-tech companies (I had 13 total interviews with various members of Palo Alto Networks -- and they ended up not hiring me).
A10 Networks people were efficient, asked great questions, were helpful, and punctual. The whole interview experience was a positive one for me. I can't think of one negative element of it.
One other thing I can attest to is that when they said they'd contact me by such and such a date, they did. When they said, they are open to new ideas, they were. When they said they believe in team, they do.
Some companies follow through with their word, A10 Networks does.
Lastly, everyone was professional, well prepared, and asked great questions. The interview process was more like a conversation and I never felt uncomfortable.
I would recommend A10 Networks to friends for sure.