Etienne is great. As a TA for Professor Grinspun, his performance is consistently above and beyond the call of duty. He routinely stays long past his posted office hours to finish addressing our questions, and sometimes holds extra office hours as needed (including after class). Etienne is one of the few TAs I've seen who actually takes the trouble to attend Professor Grinspun's lectures. The occasional course lectures he has given are as clear as the professor's, and it would be hard to improve on that level of clarity. Etienne's other responsibilities include writing the homework assignments. He is very good at making homeworks appropriately difficult (challenging but not impossible) and using homework to supplement the educational content of the lectures. He is also patient about clarifying our questions. The homeworks prepared us well for the exams, which Professor Grinspun wrote.