MongoDB Certified Developer, Associate Level Exam

Yesterday I got the positive results of the C100DEV: MongoDB Certified Developer Associate Exam that I took one month ago on October 7th, being this my first professional certification.


Back in February I decided to join some of the free courses that MongoDB offers on-line. These courses run during seven weeks and each lesson consists of short-videos and quizzes with a final homework assignment that has to be finished before the end of the following week. At the end of the seventh week there is a final exam that counts half towards the final grade, being the six weekly assignments the other half.

It was pretty interesting to invest time on it as I gained a deeper knowledge of MongoDB, successfully finishing the M102: MongoDB for DBAs in April with a 96% grade and the M101JS: MongoDB for Node.js Developers in May with 95%.

MongoDB invited in September some of their former students to do the pilot exams in a new testing platform, but I made it just to the waiting list. Surprisingly and with the examination period already started, one of the 50 spots was opened and I registered to take the exam. Problem was that I had less than three days to prepare the exam.

With such a short time to study I decided to buy the book MongoDB: The Definitive Guide, 2nd Edition by Kristina Chodorow. And although I couldn’t read it all, it helped me a lot to prepare the exam as it’s really detailed and easy to follow. Together with the free courses, this book it’s a good investment to face a certification exam.


The exam was scheduled at 9:00 am in Examity and after being introduced to my proctor (a friendly Indian guy who watched me along the duration of the exam), verify my ID to check my name and my face, and show him my room and desktop to find cheat sheets; I had 90 minutes to complete it.

If I recall properly there was 54 questions which are multiple choice, what adds certain complexity. These questions were divided in seven blocks starting with Philosophy & Features. The trickiest ones were all the referred to CRUD (Create, read, update and delete operations). Indexing and aggregation were easy to follow with some thinking. Data modelling was pretty straight forward. And although I was a bit scared before the test about Replication and Sharding; at the end they were the easiest probably because these tasks are more related to the database administrator than to the developer.

I passed the exam with a score of 637 when the minimum required was 490, what makes me estimate that I failed just six questions.


57 thoughts on “MongoDB Certified Developer, Associate Level Exam

  1. Hi Pablo, Nice to read your comments. I have been thinking of taking the certification myself. I saw that exam is based on MongoDB version 2.6. But just recently Mongo DB 3.0 has been released. Which version should I study for the certification. Will studying 3.0 version create a problem for me in the exam?

    • Hi Ravi!

      I had a quick look to the changelog and you should be all-right studying the 3.0 version as sooner or later they will change it. There shouldn’t be many differences as the core is the same but things like “In MongoDB 3.0, replica sets can have up to 50 members.” or “Arbiters can only have 1 vote.” could be part of the exam.


  2. Hi Pablo, I am planning to take exam next month. Once I pay the fees the exam date I can select for the given duration or this is planned by mongodb university people. Please let me know. ~Pratik

  3. Hi Pablo, I took Free courses online and planning to give certification exam,so I just wanna make sure whether the quizzes and homework gonna be counted or it’s just according to exam performance?

  4. Hello Pablo, I have one question about the exam, do think that is enough to make the mongo developer course to get the certification without the need to make the DBA exam?

    Regards from another Logrones living abroad. And as far as I know I think we have a common friend, Javier Perez Castaneyra aka Canario

  5. hi Pablo,

    I’m taking the Developer Associate exam in a week’s time. So, I’d like to know the topics I must put more focus on.
    You had mentioned that the questions in the Developer Associate exam were categorized into 7 blocks/sections. Are those categories the ones listed below ?

    – Philosophy & Features
    – CRUD
    – Indexing
    – Aggregation
    – Data Modelling
    – Replication
    – Sharding

    Were there any questions based on “Security”, “Storage”, “Administration”?


  6. Hi, first of all, thanks for the tips here, I have a question you said that the exam is multiple choice, but is in the format when they told you how many answers are correct as (select 2 of them), or it totally open. Taking in consideration the course quizzes in the lessons, do you think the certification exam have the same degree of difficulty or questions are harder. Thanks for the help

  7. Hi Pablo.
    Thanks for your response, I took the exam some weeks ago and today I receive my score and I passed, as there are not so much places in which people talk about the exam I would like to write here some tips that could help to obtain higher score.

    When I bought the exam I received “Exam + study guide”. But I never found the study guide and took the exam without read it (BIG MISTAKE), so my advice is find that guide and read it before the exam, put close attention to the practice questions that are there as they are very similar to the hardest of the real exam. Also review only the topic listing there.

    One thing that could help you to gain some points is be sure what it meas nUpserted, nModified, nInserted, when you do the update, and the meaning of “mutate” keyword.

    As you said, questions comes in the format of choose all that apply, without any information about the number of the correct options, based on my performance report CRUD and Index Performance were the more challenging, do some basic exercises about query and indexes to really understand which are using where.

    Hope that help to the people taking this exam and thanks Pablo for sharing your experience.

  8. Hi pablo,
    Actually i am preparing for mongoDb developer Associate exam and while registering it is offering the study guide. Do you have any idea about that ???? what is that study guide and what all topics it cover???

  9. Hi All,
    I am going to take MongoDB Certified Developer Associate Exam on 13th December, 2016. For exam, I am referring MongoDB: The Definitive Guide, 2nd Edition by Kristina Chodorow. If anyone have sample questions, please share on Your necessary help appreciated.

    • Hi Trushant
      I am also preparing for the exam, At the moment i am referring only two things
      1. the MongoDB Definitive Guide.
      2. the document which are there on the web site of Mongo University.
      Wanted to check do i need to refer any other book.
      Also if you have any sample question please can you share the same too at
      Satbir S

      • Have you given exam ?? If Yes, please give me questions idea. I am referring material as like you and I have scheduled exam on Tuesday @6 pm

  10. Hi , I am planning to take mongo developer certification. How long will it take to prepare for the exam? Is it tough ? what are the documents to refer?

  11. Have a collection students:

    { “student_id” : 4,
    “assignment” : 1,
    “score”: 18,
    “subject”: “physics”,
    “section”: 3 }
    Each student document contains the score for a single assignment. grade for a student is calculated as the avg of their assignment score in that subject.

    db.student.aggregate([{ “$match” : {“subject”: “physics”} }, {“$group”:{“_id”:(Part A), “avg” : {$avg : “$score”}}}, {(Part B): {“_id”: {section: “$_id.section”}, “best_grade”: {(Part C) : “$avg”}}} ])
    what is Part A, Part B and Part C are?

  12. Hello. I’ve started working with mongo and know crud and driver integration only. I want to take up the exam for developers and I was hoping I could get a rough estimate of the time I’d need to cover everything else. Ik it’s a very subjective question but I really just want a rough estimate so I can make a schedule for preparation. Thank you!

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