2-3 months, phone screen, multiple interviews.
Answered - Senior Director of Engineering (Current Employee) - Cambridge, MA
A few weeks to a month. There is a technical phone screen, then a full day on-site technical interview. Knowledge of networking (TCP, TLS, DNS, BGP, IPv4,6), data structures (hash tables, binary trees, etc.) and the common interview questions (elevator, how does the web work, explain DNS, etc.) are commonly used. The interviewers are more likely to be supportive and collaborative than arrogant and challenging for the sake of disorienting you (as is the case in other companies).
Answered - Senior Software Engineer III (L6) (Current Employee) - Cambridge, MA