Hi Savio,
The essay is a closed book exam, you will be asked to leave all your belongings (cell phone, backpack, books, notes, etc) before entering the exam room.
The duration of the essay is 120 minutes and you will be presented with 8 questions, so expect to spend no more than 15 minutes per question.
The questions will
test your knowledge about the design you created for the assignment.
You should expect the questions about what technology you have selected for some particular tier, what alternatives you considered, and why you rejected the alternatives.
There will also be questions about how your design handle some particular functional or non-functional requirements.
Contrary to Part 1 exam questions, the questions for the essay aren't a secret and are available in the books and over the internet.
Allen / Bambara book, for instance, has exhaustive list of questions for the Part 3, and I can confirm that all questions I had on my essay are in this book.
If you do not have this book, here 's the link to some blog with the list of questions roughly equivalent to the one in the book:
https://srinichekuri.wordpress.com/2013/06/04/sceaocmjea-essay/
I probably would not recommend adopting the answer style provided by Allen / Bambara book, as the answers provided are very very verbose and
it is hard to produce this much of typed text for anyone who is not a professional technical writer with descent typing skills.
I took a 9 days break after I have sent my assignment and before the essay, and spent this time creating answers to all questions from Allen/Bambara book.
My target was to provide all the information I know about the question, in shortest form possible.
I think the answers I prepared were somewhere within 200-300 words range.
On the essay exam, I typed 2 hours non-stop, and I guess I could have spent another hour for better answers, and I am not sure if I would succeed if I did not take that 9 days for the preparation.
Good luck !