• The Beginning It was business as usual at the HackerRank office. As the HackerRank Community team gathered to plan the next quarter, one of the topics that came up was the Tech debt we will address this quarter. To give some context, every quarter in our team we pick two Tech debt items – one…

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  • Parallel execution of test cases

    When you submit a code on hackerrank.com; it’s processed on the code execution platform that we call codechecker. Over the past 2 years we have invested a lot of time into profiling and improving key metrics which aided in cutting down on user’s wait time. Overview Steps involved in processing a code submission is sequential.…

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  • October 2017 Codechecker Performance Report

    This is the third post in the series of posts detailing Codechecker, specifically on scale, performance and security aspects. You can read all the posts here in our codechecker posts. In October, we increased our number of servers compared to September or August. This was a simple experiment to see how additional servers would impact…

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  • How We Used Stratified Sampling to Generate Unbiased Predictions

    Introduction Over these past few months, the Data Science team here at HackerRank has been analyzing our own internal hiring data to see what we could learn from it. For example, which factors are the biggest predictor of success when evaluating talent using skill assessments? What else can we learn about candidates from just their…

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  • September 2017 Codechecker Performance Report

    This is the second post of a series of posts detailing Codechecker, specifically on scale, performance and security aspects. Among many performance metrics that we track, the top 3 metrics in priority are total submission count, queue time and total turn around time. Total Submission Count – Total number of code submissions processed. Queue Time…

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  • August 2017 Codechecker Performance Report

    Ever wonder how HackerRank can support evaluation of hundreds of thousands of participants? Codechecker is our in-house online judge built to handle infinite scale. This is the first of a series of posts detailing Codechecker, specifically on scale, performance and security aspects. Among many performance metrics that we track, the top 3 metrics in priority…

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