In translating the three volumes of Reiner Stach's biography of Franz Kafka - The Time of Decisions, The Time of Knowledge and Friends of Youth, published by Cherche Midi in the last two years - I have accumulated observations and especially questions on this literary genre that is rarely highlighted. The author has kindly agreed to answer these questions.They are not about his subject, but about his method - to the extent that the one and the other can be separated. I hope this interview will shed some light on the specificities of a writing style devoted like no other to the reconstruction of a foreign life.