to answer the question in general - not sure if vapi supports this (someone else with better knowledge could pitch in), but I might consider using a durable process, like azure durable functions (and more recently - aws durable functions), and then break down the interview process into multiple checkpoints with retry/resume as needed. Alternatively, and perhaps easier (again - if possible), maybe have a database that includes phone number + which step of the interview the call has gotten to, and then in a dropoff check the database and resume from the given step?