How I Prepared for Launch School's 109 Oral Assessment

A couple of weeks ago, I took Launch School’s first oral exam (RB 109). Since I’m now somewhat stuck on the next lesson, I thought it’d be best to reflect on the road taken thus far.

You’ll find here my time logs and general advice regarding this Launch School exam.

I’ll include the same disclaimer as in my previous related article: the timelogs included are entirely personal, and should not impact your own study flow.

Getting through Launch School’s 101 course

First, let’s answer the big question, the one that tormented my days in the Preparatory course: How long does it take to get through course 101?

Of course the answer is: it varies. On your time commitment, on your previous coding experience, on how easily you can grasp the difficult concepts, on how much repetition your memory needs, etc.

Therefore, the answer provided here is nothing but the time it took me to pass this course.


Overall, it took me 156 hours of active learning to pass Launch School’s first course. I studied for approximately 2 months and a half (72 days), with an average of more than 2 hours per day. The daily effort varied greatly, from 30 min to more than 5h per day - as I had other commitments, like my day job 😒

However, I tried to study every single day (even during my week-long holiday). I wanted programming to become one of my natural routines, and I felt that daily practice probably helped my memorization.

My Github commit history
Proof: my Github commit history 💚

Time breakdown

I’ll detail here the time spent on various topics, for the entire 101-109 course. I’ve done a similar table for the written assessment, and felt it’d be weird to only detail the time I spent afterwards preparing the oral exam. Indeed, the time spent for the written exam greatly prepared me for the oral exam as well, therefore splitting the two didn’t really make sense to me.

Without further ado, here’s my time breakdown per topic:

Topic Duration Percentage
Lessons 33.5 hours 21 %
Video Lessons 6.5 hours 4 %
Walk-through / Assignments 12 hours 8 %
Ruby Small Problems 59.5 hours 38 %
Practice Problems 10 hours 6 %
Code Wars 12 hours 8 %
Live-coding 15 hours 10 %
Exams (incl. quizzes) 7.5 hours 5 %

And per lesson:

Chapter Duration Percentage
Lesson 1 7 hours 5 %
Lesson 2 21 hours 14 %
Lesson 3 14.5 hours 9 %
Lesson 4 20 hours 13 %
Lesson 5 14.5 hours 9 %
Lesson 6 10 hours 6 %
Assessment Preparation 68.5 hours 44 %

Key Take-Aways

What to make of these tables?

1. ⌛ Almost 50% of my time was spent working after the end of Lesson 6

When I prepared this article, this is the first thing that struck me: 44% of my time on 101 was spent in the Assessment preparation part, where my “only job” was to make sure I had indeed fully understood the material.

Within this period, I’ve spent my 68 hours doing the following:

Topic Duration Percentage
Reviewing lessons 16 hours 23 %
Ruby Small Problems 22 hours 32 %
Live-coding 15 hours 22 %
Code Wars 12 hours 18 %
Exams 3.5 hours 5 %

Going through the lessons was not enough for me: I needed to practice for dozens of hours afterwards before feeling ready to tackle the exams.

You may have noticed that I spent a significant time live-coding, either during TA sessions or with another fellow Launch School student (hello Dimitri!)

This was by far the most important part of my preparation, and I think what was decisive for my good exam grades. I cannot recommend this enough: if you’re currently preparing for the 109 exam, please register to a TA study session, and practice on 1-to-1 with another student!

Solving a code problem and explaining out loud your thought process are two difficult and different skills. My first live coding attempts were disastrous: I misread the instructions, kept getting errors on my method implementations, and was half-panicked.

But fortunately, with a bit of practice, solving problems in front of a peer becomes much easier.

2. 👩‍💻 Practice, practice, practice

If you do the math, I’ve actually spent 60% of my overall time practicing code. The Ruby Small Problems, the Practice Problems, the Code Wars katas and the Assignments amounted to more than 90 hours.

The reason behind this is simple: as with any skill, you need to build your muscle memory. And the secret ingredients are: 1) practice, and 2) practice.

How my interview went

My interview was with Srdjan and lasted for about 20 minutes; I received two exercises.

During the first one, as usual, I misread the instructions, and only realised my mistake once my code was written and half of my test cases refused to pass. Oops. 🤦‍♀️

At that point, I was fairly sure that I’d blown my interview. What (probably) ‘saved’ me was: going back to the algorithm part of the PEDAC process and solving the actual exercise there before attempting another line of code. And this time, it worked!

The second exercise went quite smoothly.

During the interview, Srdjan was pretty silent, which can be intimidating. I received my grades less than 2 hours afterwards, and I had actually passed the exam 🎉

If you’re currently preparing the 109 Launch School exams, good luck! 🤞 You might want to check out those two other posts: