Codility Test for Developers: How to Excel in Your Online Assessment

Codility serves as an online coding platform used by various tech companies, including Microsoft, Check Point, Amdocs, and others, for conducting Online Assessments. This automated coding test is subsequently reviewed by a professional. Typically, candidates are presented with three questions to be solved within 60-90 minutes.

The Online Assessment, also known as the Online Technical Screen (OTS), constitutes one of the initial stages in the hiring process, often involving a Codility interview, a phone interview, or a combination of both.

Your code undergoes automatic grading based on its efficiency with all possible inputs:

• 100%: Automatic Pass
• 60% ior below: Automatic Reject
• 60%-100%: Code needs to be reviewed.

During the review process, your code is evaluated for its optimality and your comprehension of the solution.

Technical interview questions generally assess fundamental algorithm and data structure knowledge. The Codility test may include:

• Debugging Questions
• Coding questions requiring the implementation of data structures and algorithms (e.g., Strings, Binary Trees)
• Multiple Choice Questions (MCQ), for example: "How many comparisons do you need to find the minimum value in a 5-element array?" Answer: (n-1)(4)

You may also be queried on computer subjects like:

• Operating systems
• Database Management Systems (DBMS)
• Computer Networks

Common question topics on the Codility Test include Arrays/Strings (most frequent), Linked lists, Binary trees, Search/Sort, Dynamic programming, and Bit manipulation. While covering all these topics may seem extensive, practicing the most common questions will significantly save you time and effort.

You have the option to choose your preferred programming language before commencing the test. Similarly, using the Prep Course, you can start practicing the language you are most comfortable coding in (C++, Java, Python, or JavaScript).

The difficulty level of the Codility test varies based on the company you are interviewing for, your level of experience, and the specific role you are applying for.

The main challenges in the Codility Test include working under time pressure and the inability to directly communicate your thought process to the interviewer.

Due to these challenges, many individuals end up with blank answers, leading to failure in the code review.

Navigating through all coding questions within stringent time constraints can be challenging and, at times, impractical to devise optimal solutions for every query. Learning strategies can ensure there aren’t any questions left unanswered due to time limitations.

Recognize and work on improving your coding speed. Understanding your own pace allows you to efficiently manage your time during the actual Codility test. Engage in timed Online Assessment (OA) simulations to familiarize yourself with coding under time pressure and reduce stress in the real test environment.

Gain a comprehensive understanding of data structures and algorithms. Practice extensively on commonly asked question topics such as Arrays, Linked Lists, Binary Trees, Search/Sort, and more. This preparation ensures you are ready to tackle any type of question that may arise in the test.

Enhance your problem-solving skills by practicing numerous questions with complete solutions. This will help you:

• Pose essential clarification questions when faced with a new problem.
• Explore different and alternative solutions for the same problem.
• Approach new problems with greater ease and confidence.

 It is crucial to convey your reasoning and provide comments during the Online Assessment (OA). Here are some tips to improve your communication:

• Verbally express your thought process while solving each coding problem.
• Use clear and formal coding concept names in your comments.
• Create explanations using logical sequences. 

When tackling a problem, consider initiating the process by asking relevant (but not excessive) clarification questions. If questioning isn't possible, no worries. Document your queries in comments, accompanied by the necessary adjustments for each case’s scenario.

Demonstrate your comprehensive understanding of the solution by commenting on your code's time and space complexity, as well as its advantages and limitations.

Take the Codility demo test to become familiar with the coding platform and alleviate stress during the actual Codility test. Keep in mind that Codility questions may vary from one company to another.

The Codility test is a component of the hiring process for roles like SDE1 in companies such as Microsoft, Check Point, Matrix, Amdocs, HP Indigo, and Facebook.

1-2 days before the scheduled interview, a link to the Codility test will be provided. You can open the link to read the instructions; it’s important to mention that it’s not mandatory to initiate the test at this stage.

Typically, Codility requires you to activate your camera. Ensure that you are dressed appropriately, and if you’re contemplating any form of cheating, it's advisable to reconsider it.

Codility usually records the entire history and encompasses runs and corrections. Imperfections are not a drawback; they provide insights into your problem-solving approach for the reviewer.