ⓘ CodeSignal


ⓘ CodeSignal

CodeSignal is a skills-based assessment platform operated by American company BrainFights, Inc., whose mission is to discover, develop and promote technical talent. Founded in 2014 and headquartered in San Francisco, CodeSignal applies game mechanics that offer developers of all skill levels online computer programming challenges for both instructional and recruiting purposes.

As of August 2017, CodeSignal has reported that it had nearly 1 million developers using CodeSignal for Developers.

As of 10 July 2018, CodeFights has been renamed to CodeSignal with additional features as per the company blog.


1. History

CodeSignal was founded in 2014 by Tigran Sloyan, Aram Shatakhtsyan, and Felix Desroches. The idea for CodeSignal was developed from Sloyan and Shatakhtsyan’s experiences of participating in international coding and mathematics competitions including the International Olympiad in Informatics and Mathematics. Sloyan even used this concept of a game-based teaching platform for his Computer Science master’s thesis at MIT, but abandoned the idea to work in established Silicon Valley companies including Oracle, Google, and Premise backed by Google Ventures.

CodeSignal first launched with challenges only for JavaScript and were based on "code battles", a 3-minute person versus person competition to determine who can more quickly and accurately debug existing code. Before each game, players can either choose to race against the clock, or let CodeSignal automatically match them with other online players to complete the challenge head-to-head. Successful challengers level up and earn badges towards language fluency. Even though players are first presented with short challenges that take only a few minutes to solve, each challenge increases in difficulty and the amount of time given to solve the problem.

Soon, CodeSignal expanded to support Java, C++ and Python challenges. Today, CodeSignal supports 38 programming languages and has also expanded to include more types of challenges, interview practice, and access to companies with open software engineering positions.

Even though CodeSignal launched as a platform to help users learn and improve their coding skills, CodeSignal has also taken on changing recruiting all together. CodeFight’s main goal is to help programmers get hired based on their skills, not their resume.


2. CodeSignal for Developers

CodeSignal originally launched as an online community where developers can practice their skills through a series of Head-to-Head coding challenges, which appealed to competitive programmers. The main goal was to help developers build their coding skills by solving and discussing programming challenges with other developers on the platform.

In the first 2 years, the CodeSignal platform had 6 distinct game modes: Interview Practice, Company Bots, Arcade, Tournaments, Head-to-Head, and Challenges; all geared towards helping developers build skills and getting prepared for technical real-world jobs. In all of these modes, the CodeSignal system runs a user’s solution to a coding challenge against tests, and the solution is only accepted when all test cases are satisfied. All CodeFight modes for developers are free of charge.

As of August 2017, CodeSignal has reported that it had nearly 1 million developers using CodeSignal for Developers.


2.1. CodeSignal for Developers Interview Practice

Interview Practice is the newest and most popular mode on CodeSignal for Developers. This mode first launched in beta in February 2017, and then launched the expanded the version in June 2017. The Interview Practice game mode is specifically targeted towards job seekers who are preparing for engineering technical interviews. Developers can use Interview Practice to solve real interview questions, master key computer science topics, and learn by reviewing solutions provided within the community.


2.2. CodeSignal for Developers Company Bots

Launched in November 2015, Company Bots are curated challenges that simulate real-world problems that companies are facing. This type of assessment is based on the premise that solving on-the-job coding challenges can allow companies to better assess the skills of a potential candidate.

During a Company Bot challenge, participants are faced with multiple rounds of challenges of varying difficulty. Both the bot and the challenger are attempting to solve the coding challenge side by side. Each participant gains points based on speed and accuracy. After the participant submits their solution, it is evaluated and only accepted if it passes all the tests. Only after winning the Bot challenge, can the participant be provided with the opportunity to submit their information to the recruiter of the company running the Company Bot challenge.

CodeSignal launched Company Bots with a partnership with Uber to create Uberbot, a Uber-branded gaming challenge on CodeSignal that would help Uber find and evaluate the programming skills of candidates. Candidates who attempted the Uberbot coding game are challenged to solve real-world problems facing Uber’s engineering team, such as finding the most optimal route for a Uber ride, or the most efficient method of matching riders for an uberPOOL.

CodeSignal now has 15 company bots including bots from Asana, Dropbox, Quora, Instacart, SpaceX, Thumbtack, and others.


3. CodeSignal for Recruiters

In addition to being a learning tool for developers, CodeSignal Recruiter previously known as CodeSignalR is also a skills-based recruiting platform that uses a data-driven approach to help companies improve their hiring process, find better qualified candidates, and make more objective hiring decisions.

Launched in October 2017, CodeSignal Recruiter is the sourcing, testing, and interview platform for technical recruiters. Companies with a CodeSignal Recruiter account can contact developers within the CodeSignal community who have done well on challenges and have signalled that they are open to new jobs. Once contacted, recruiters can use CodeSignal to send out custom programming tests to candidates that include plagiarism checks, live recordings, timed assessments, all within a developer-focused IDE integrated development environment.

CodeSignal Recruiter is also integrated with Applicant Tracking System ATS software including Greenhouse, Lever and SmartRecruiters, which allows recruiters to manage and sync candidate data between CodeSignal and their recruiting platform including send coding tests, evaluating results and managing candidate lifecycles.

Some of CodeFight’s Recruiter customers include Evernote, Uber, Thumbtack, Dropbox, Asana, Ascend, Wizeline and Quora.


3.1. CodeSignal for Recruiters CodeSignal Coding Score

CodeSignal launched their rating system, called Coding Score, on July 10, 2018. The Coding Score is a measure of a developers overall implementation and problem-solving ability. It is a predictor of how well a developer will perform in technical interviews. To get a initial Coding Score on CodeSignal, each developer has to solve at least 3 tasks on CodeSignal. To get a more accurate score, developers are asked to vary the difficulty of the tasks that they solve.


3.2. CodeSignal for Recruiters Testing

CodeSignal Recruiter also has a testing feature that allows recruiters to send out technical assessments to their potential candidates. These tests can be customized to simulate real-world challenges that the candidate may face on the job, which has been reported to be a better measurement for competency than regular interview questions or theoretical programming tests. The testing suite also has a built in plagiarism checker that predicts the probability of plagiarism by comparing to other completed tests on the CodeSignal platform and solutions from known sites. During the on-boarding process CodeSignal works with customers to create custom tests so the online tests are calibrated with the interview process and job responsibilities.


3.3. CodeSignal for Recruiters Interviewing

The CodeSignal Recruiter Interview feature allows recruiters to conduct online and in-person interviews in a shared coding environment that supports 38 programming languages. The interview environment allows for timed assessments, live recordings, and an extensive library of skills-based coding tasks. During each live interview, the hiring manager can watch and conduct a coding skills assessment using pre-defined coding tasks while also talking to the candidate over a live video stream. Each live interview is also recorded so that other hiring managers in the recruitment process can review and share the candidates live assessment.


4. Funding

As of July 2017, CodeSignal has raised a total of $12.5 million in 2 rounds from 23 investors. The company raised an initial $2.5 million in seed funding in April 2015, which included investments by Felicis Ventures Aydin Senkut, Sutter Hill Ventures Mike Speiser, LiveRamp CEO Auren Hoffman, Google Shopping Express founder Tom Fallows, Twitter VP of Engineering Raffi Krikorian, Quora CEO Adam DAngelo and GoDaddy VP of Engineering Marek Olszewski. CodeSignal raised $10 million in November 2016. The Series A funding round was led by Other investors in that round included SV Angel, A Capital, Granatus Ventures, and Felicis Ventures.


5. Reception

Within the first 6 months of its launch, CodeSignal featured over 1.500 challenges, which attracted over 70.000 users who solved over 1.5 million challenges. From there, CodeSignal was reported to grow by 30-40% month-over-month.

As of August 2017, CodeSignal has reported that it had nearly 1 million developers using CodeSignal for Developers.


6. Languages Supported

CodeSignal supports 38 different coding languages on its platform. However, not all tasks on the site can be solved using every language, based on the challenge type.