What it takes to be the Meilleur Dev de France 2017 (the Best Developer of France).

Photo by: Caroline C

Last week, the 5th edition of the Meilleur Dev de France took place at Station F, the largest start-up campus in Europe and had over 7000 people in attendance that included 700 coders and some of the nation’s best companies. Like previous editions, Criteo’s engineers Came they Saw and they Conquered.

Stephane Le Roy, a Senior Software Engineer in our R&D emerged winner at this year’s contest, finishing the competition within 23 minutes. I sat down with Stephane to know what it takes to be the best developer in France and what he plans on doing with his prize money.

What does winning Meilleur Dev de France mean to you?

While I’m very proud of winning, this kind of contest focus mainly on some useful skills for a developer such as coding and problem solving. However, there are many other skills (eg. soft skills) like communication or teamwork that makes a great developer. In reality, I am far from being the best developer in France. Maybe the best developer in my small neighbourhood (as my t-shirt states). 😊

Meilleur dev du quartier

We’re told all developers in the competition are allowed to code in any language of choice (which is great). What was your choice and why?

While I use mostly Scala at work and sometimes C# or Python, for programming contests, I prefer C++, because it’s fast and can be more concise than one might think and its standard library has a lot of useful features for algorithms. But the main reason I used C++ is that it’s the language I am the most familiar with (in a speed based contest like this, you don’t have the time for stackoverflow.com).

Can you tell us about the your favourite or most memorable moment during the competition?

I have two. After I solved the last question during the finale, I looked around and realized other competitors were still working on their problems. A few minutes after that, I noticed that Lowik Chanussot, another finalist from Criteo had also finished all the problems. At this point, we had to wait for 45 minutes for the end of the competition, relaxing a little (while others were still competing) and  silently enjoying our 1st and 2nd places.

The second, on my way home in the subway after the contest, I found myself with this giant wooden check almost my height (glad the real one came in less cumbersome). The situation was quite unusual.. 😊

You were part of last year’s contest right? Why did you choose to come back this year and what was different from last year’s contest?

Yes I was. Last year, there were a lot of people that could not connect to the Wi-Fi provided in the venue, but luckily for me I didn’t have this issue, and I managed to finish 4th place. While I was really happy with this result, it was frustrating to see me come so close to the top 3,  so I aimed for the 1^st place this time around, even if in my head I knew winning was quite unlikely (so many things could go wrong in this kind of contest: a small bug, a misunderstanding of the problem statement, a technical issue, under evaluating the time complexity of an algorithm, etc.).

To achieve my goal,  I participated in several training sessions we had at Criteo, and also prepared few implementations for some classical algorithms like max flow, or matching for bipartite graph.

Did your daily job at Criteo impact your performance in the contest?

In my team in Criteo, we work on distributed algorithms for graphs on Spark/Hadoop and like other teams, we have to handle a huge amount of data every day, so it’s a constant challenge to find optimized algorithms. This can explain why myself and other Criteos performed well in the Meilleur Dev de France, almost one Criteos out of two qualified for the finale!

What would it take to put three Criteos on the podium next time instead of two?

I know few very strong coders at Criteo who weren’t around during this contest, but could definitely end on the podium next year!

Photo: www.meilleurdevdefrance.com

The question on everyone’s mind, How will you be spending the 10 000 euros?

To be honest, I don’t have any ideas for now. Can you help me with any?

Haha… Trust me I sure have a million ideas already.  What’s next for Stephane Le Roy?

Before the next Meilleur Dev de France, I will probably participate in a few other contests such as, Topcoder “Marathon” competitions, which are longer contests, with only one problem but more focused on optimization.

If you had a magic wand, is there anything you would like to change in the developer world as it is today?

I started to work a decade ago, and I think the situation hasn’t changed much since then, or is even worse: the number of women in computer science is way too small. I think this is due to bad reasons (like for example the stereotypes about developers).

So if I had to change one thing, it would be this.

Thank you for your time and I wish the best ahead. 

 Interview by:

Ibrahim Abubakari & Stephane Le Roy