Jul 22 (Sat) 2017, 4:30 am UTC to Jul 30 (Sun) 2017, 6:29 pm UTC



In the context of Online Classifieds, buyers want to find ads that are relevant for them. In order to help our users do that, we at OLX want to be able to show them those ads by predicting the chance of any particular user of contacting the seller of any particular ad.

We challenge you to predict the ads that any particular buyer will contact for the first time in the next 7 days grouped by category, within the limited scope of users that are only browsing and not searching. We will provide you with a training dataset containing the behaviour of a sample of users until a specific day. Also, the detailed information of all the ads available on that day and the information about the ones the users interacted with.


1st Winner

MacBook Pro

2nd Winner

Apple iPad Pro + Pencil

3rd Winner

GoPro Hero 5

4-10 Winners

Kindle Paperwhite


OLX Goodies for Top 100

Opportunities at OLX

We’re a global company and have our engineering offices in the following locations.

Delhi NCR




Buenos Aires,


  • 1. The contest is open to everyone above the age of 18 years. However, only participants residing in India are eligible to win prizes.

    2. The contest is open for 5 days. The contest starts on Saturday, July 22th, 2017 10:00 AM IST and ends on Thursday, July 27th, 2017 09:59 AM IST.

    3. This competition will appeal to coders who are interested in Data Science and Machine Learning.

    4. This is a 2 tier coding competition. Top 150 in the first round (online) from India will be invited to next "in-person" events in Gurgaon & Bangalore on 5th & 12th August 2017 respectively. Additional prizes and job opportunities will be on offer for winners of the second round.

    5. This is an individual participation competition.

    6. Scoring details for the challenge will become available when the contest begins. Hackerrank’s scoring decisions are final for system-graded challenges.

    7. All submissions are run through a plagiarism detector. Any case of code plagiarism will disqualify both users from the contest.

    8. Prizes shall reach the winners within 6 weeks of completion of the online challenge.

    9. Winners could be asked to demonstrate their work and share their code.

    10. OLX employees are ineligible to participate.


  • 1. Each challenge has a pre-determined score.

    2. A participant’s score depends on the number of test cases a participant’s code submission successfully passes.

    3. If a participant submits more than one solution per challenge, then the participant’s score will reflect the highest score achieved. In a game challenge, the participant's score will reflect the last code submission.

    4. Participants are ranked by score. If two or more participants achieve the same score, then the tie is broken by the total time taken to submit the last solution resulting in a higher score

    5. For the machine learning challenge, the dataset is split into 3 parts. 50% of the dataset forms the training set, which will be given to participants to formulate their solution. 25% of the dataset will form the online evaluation dataset. When participants submit their solution, it will be evaluated against the training set and the online evaluation dataset to determine their position on the leaderboard. The last 25% of the dataset will be used for offline evaluation. When the contest has ended, all participant solutions will be evaluated against the offline dataset to determine their final position on the leaderboard.

Life at OLX

The OLX Group is a network of leading classifieds platforms in 45 markets, including the brands OLX, Avito, Letgo and dubizzle.

The OLX Group connects local people to buy, sell or exchange used goods and services by making it fast and easy for anyone to post a listing through their mobile phone or on the web. Hundreds of millions of people in local markets around the world generate more than 1.7 billion monthly visits, 37 billion monthly page views and 54 million listings every month on the OLX Group's online marketplaces.

Our 4000+ committed employees are making a difference from our 25 offices across the globe. OLX is one of the largest e-commerce sites worldwide. OLX is designed to enable people to connect through buying and selling goods and services quickly, easily and for free.

In an open culture that encourages own initiatives, growth, and entrepreneurial spirit. Sharing the same values. At OLX we have a clear ambition - to create a richer world. We empower people to make the difference and we’re always looking for great people to help us do just that.

It's all about the big picture!