#TuentiChallenge5: First round!

Posted on 5/06/2015 by Alfredo Beaumont, Senior Software Engineer

The first round of the fifth edition of Tuenti Challenge ended as scheduled on Monday at 13:37 hours. With 2342 registered people in this first phase, 863 people were able to solve at least one problem, after spending the whole week on them, and 617 people were able to solve, at least, one of them correctly. This year the challenges were pretty hard and no one was able to reach the final problem. You can see the full final ranking of the first round here.

The most used languages by the contestants of this edition were Python, C, Java and C++, as you can see in the graph.

Graph with rank of solutions per language

Tuenti Challenge is a competition for showing our technical skills and allowing people with technical interests to have a good time while giving visibility to Tuenti as a company that is firmly based on technology in order to find especially qualified individuals for our team. The problems are a combination of programming, security and ingenuity challenges.

To continue hacking or to complete any unfinished exercises, the webpage for the Challenge will remain available until next year ;) We would like to congratulate the 50 classified contenders and thank everyone for participating! Now, for the second round. This is becoming more and more exciting!

The #TuentiChallenge5 registration is open!

Posted on 3/09/2015 by Daniel Pañeda and Alfredo Beaumont, Software Engineers

No more waiting. The fifth edition of the annual programming contest is finally here, Tuenti Challenge. Today we are opening the registration for participants to begin warming up by solving the problems and overcoming the challenges from previous editions.

The contest, like every year, will consist of 2 phases: The first phase, which will last from the 27th of April to the 4th of May, is on-line and the participants will have to solve the 20 problems posed by Tuenti's engineering team. The 50 finalists from this phase will be those that solve the greatest number of posed challenges in the shortest amount of time. The responses from the 50 initial winners will be manually reviewed by Tuenti's engineering team, who will take into account variables such as the chosen algorithm or the clarity and quality of the implemented code.

The second phase which will take place on the 28th and 29th of May at Tuenti's offices in Madrid, the 10 best participants from the first phase will have the opportunity of spending a day working directly with the team and participate in training sessions at the office. Also, they will all receive a prize and some of them will be offered a job.

Therefore, Tuenti Challengers, lets start writing code. Registration will begin today at 13.37 hours (GMT+1) and will remain open until the same hour on the 4th of May, at which moment the first phase of the contest will have been completed. All the information is available on the Tuenti Challenge 5 Website, contest.tuenti.net, as well as the legal rules of the contest.

Horrific #HMU24 at Tuenti

Posted on 10/31/2014 by Engineering Outreach Committee

The 24th edition of our HMU ends after 24 hours of coding with a winner team at the Tuenti office. In this edition, we focused our projects on bringing communications in the Tuenti app to the next level, so we can keep offering added value products to our customers.

The Tuenti guys started their projects yesterday at 18h and finished them today at the very same time. 24 hours non stop when there were dinner at the office, naps, funny moments, tests, redone code and tons of work to carry out.

The winners are elected by the votes of all Tuenti employees. This time, the winning project was the one by Alfredo B. and Pedro L., Tuenti Desktop FTW, a native multiplatform desktop client for Tuenti.

And what better way then to close this 24-hour HMU than to celebrate our Halloween party Tuenti style: costumes, prizes, food and drinks, music and a lot of scaaaaaary stuff!!

#TuentiChallenge4 grand finale!

Posted on 5/23/2014 by Jorge “Coque” Vas, Senior Software Engineer

Tuenti's 4th programming competition ended today after an intense day of workshops at the company's headquarters in Madrid. First of all, we would like to thank the more than 2,000 participants of this year's competition, and especially the ten finalists who spent yesterday and today in Madrid getting to know the Tuenti team and spirit.

Just like other years, a barbecue was held yesterday to celebrate the challenge and to mark the initial contact of the finalists with the Tuenti lifestyle in an informal event. This year, the terrace of our VP of Product, Philip Arkcoll, was filled with hamburgers, hot dogs and a great atmosphere.

During today's event, the finalists participated in work sessions with our engineers as well as in workshops and interviews with the Human Resources team. This was the final phase of the #TuentiChallenge4 before selecting the winners. The workshops were carried out with:

  • Luis Peralta, CTO: Delta
  • Pedro Álvarez, Senior Software Engineer: Building a VoIP Service Using Mobile WebRTC
  • Jesús Bravo, Lead Software Engineer: Tuenti Architecture
  • José Plana, DevOps Engineer: Tuenti Release Cycle

A few minutes ago, we selected the winners of the fourth edition of the Tuenti Challenge, based on the execution time of each problem and the quality of the code, among other variables. The final podium is as follows:

  1. Darío N.
  2. Leo A.
  3. Mikel A.

The participants who also reached the final phase of this edition are:

  • Ángel G.
  • Álvaro G.
  • José María P.
  • Mario R.
  • Javier S.
  • Jacobo T.
  • Daniel T.

We have just announced the names of the winners to the entire Tuenti team, and we are celebrating by giving a final touch to #TuentiChallenge4, a new edition of our famous programming competition that allows us to promote talent and expand our own engineering team.

We are thrilled with the results obtained in this year's competition! 2,000 THANKS to all the participants. We'll see you next year with more tests to rack your brain. Until the #TuentiChallenge5, aces! ;)

#TuentiChallenge4: Show me the numbers

Posted on 5/14/2014 by Jorge “Coque” Vas, Senior Software Engineer

604,800 seconds, 120,517 lines of code —this is a new line each 5 seconds—, nearly 2,000 participants, 2,054 problems solved, 1,542 problems solved correctly … but you want more details.


Almost 400 people passed the first challenge, but only 6 brave participants made it to the 20th one. Also, there were three stoppers —problems with less solvers that the next one—. Kudos to you if you were one of the participants that didn’t hit the skip button when you faced challenges 8, 10 and 13.

Time spent

Almost all the problems were solved in an average time shorter than 15 hours, but the 8th challenge kept you busy for 23 hours.

Note: The time to solve the first challenge started counting at the beginning of the contest.

Execution time

There were big differences between some submits and the others, and looks like the 14th challenge was a tough nut to crack. Waiting longer than 1 hour for your code to pass must have been a hard experience.

Top 100 participants’ choice of language

If you didn’t make it this year, you may need to upgrade your tool belt with some new fancy languages. Which are the choices of the 100 fastest participants? Maybe you want to try with Python or C++ next year.

Lines of code

The shortest code was an 8 lines tiny Python solution to problem 3. The largest code has the awesome number of 7,467 lines  —please, please, tell us you used an external library— to solve the problem 17. Here they are the total number of lines by each language.


Carlos H. did a great work compiling all the published solutions so you can check other participants’ approaches or just learn how they did  that challenge you couldn’t finish.


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