In today's remote world, the best way for engineering leaders to screen potential hires is with an online coding test interview.
Coding test interviews are coding challenges that one can solve without relying on an internet connection or an IDE. A candidate simply submits their code and receives instant feedback on their solution's correctness. This allows managers to quickly assess an engineer's problem-solving capacity and coding style.
Basically: you can choose between many potential hires without wasting time on those who are unqualified.
There's a lot that goes into building an online coding test for jobs. If you choose to create your own, you'll want to follow these 3 steps:
- Prepare problem specifications
- Post problems with an expected time limit and monitor how long it takes engineers to solve them
- Evaluate submitted solutions
This is no easy feat.
Step 1 can take anywhere from 1–3 weeks if your engineering team works together on creating a well-designed, detailed task. If one person tries to do this without help from others – it could take much longer. Usually, companies spend about a month preparing a task for an online coding test.
A good task should include algorithmic questions and reflect common problems solved by experienced programmers working on large teams/projects in real-life situations. It's important not only to provide sufficient constraints in the question but also to indicate what parts of problem specification are important for scoring.
Fortunately, you don't have to go it alone. There are several coding assessment platforms on the market that have already done the hard work for you.
Let's look at some examples.
Online coding test platform options
Finding the right testing platform can feel a bit like Goldie Locks: Engineering Edition.
Some are built for larger organizations and allow you to create and maintain test suites in one place. Others are better for start-ups because they're affordable and easy to scale. There are even tools that offer collaboration features where engineers work together on the same question at the same time.
You want to look for a platform that works with you and is designed around modern software development practices. Ultimately, you'll find the best fit when you understand your team's needs and the platforms' capabilities.
To help you make this decision, we've compiled a list of the top coding interview platforms available today.
Woven: If you need to hire senior engineers, you need Woven. Woven is the only technical assessment platform that goes beyond code to measure the full range of skills that engineers develop over their careers. Plus, get a detailed breakdown of your candidate's code and a hiring recommendation so you can make the right hiring decision.
CodeSignal: CodeSignal speeds up the technical interview process through automation. Choose from role-specific assessments like front-end, backend, DevOps, data science, and more, or develop custom assessments with their team.
Codility: There are hundreds of automated Codility challenges ranging from the basics to highly complex algorithms. Codility test questions are available in more than 20 languages, and the platform offers auto-scoring, visual reports, and video interviewing. Candidates can also utilize Codility lessons and online coding test practice.
HireVue: HireVue's assessments give you insight into a candidate's ability to problem solve and communicate. They're also auto-scored and proofed for cheating. You can explore HireVue coding challenge examples online for details.
Using an online coding test can help you hire software engineers with proven coding skills. Once you've chosen the right platform, work with the engineering team to develop a list of problems like the ones listed below.
Coding test examples
Let's say you're building a new social network for engineers. You want the project to be successful, so you need experienced developers.
To find them, use an online coding test that reflects the challenges of developing large-scale codebases with many contributors. Some problems might include:
- Create a function that accepts a list of integers and returns the largest odd number.
- Implement a function that removes all duplicates from an array of integers.
- Given a list of appointments, return all appointments that overlap in time.
- Given a string, convert it to CamelCase notation (if not already in CamelCase).
Perhaps you're creating a website that will play videos. You want to ensure your video player can handle almost any file, so you need engineers who are skilled at handling media of all types.
Here, you might use coding questions that test candidates' knowledge of audio and video encoding. For example:
- How do you determine the duration of a media file?
- In a media file, how do you find the total duration of all audio tracks?
- Extract a single MP3 track from a video file.
The goal is to come up with a set of coding problems that reflect your business needs and challenges. Your technical interview should test for more than just whether an engineer can code — it should gauge how well they can navigate the modern software development process.
Online programming test with certificate
Some candidates might worry about being judged on their coding ability. One way to put them at ease is to use a platform that offers an online programming test with a certificate upon completion.
This breaks the interview down into multiple steps, which may be easier for candidates to handle. It also gives you extra insight into how they work and problem solve under time constraints. An example of a free online quiz with certificate might be:
- A Python certification exam that takes around 45 minutes and includes 20 questions. Engineers must score a minimum of 80% to pass.
- A C++ certification exam that takes around 20 minutes and includes 10 questions. Candidates must score 80% to pass.
- A Java certification exam that takes around 25 minutes and includes 20 questions. Candidates must score 80% to pass.
You can still ask candidates follow-up questions after they complete their certification exam, too — just like you would with a traditional interview. That way, you'll have all the information you need to make a decision that benefits both parties.
Programming test for interviews
Online coding tests can't grant 100% accuracy in screening candidates. However, using them correctly can substantially increase your company's hiring efficiency and save you money that would otherwise be spent on interviewing more candidates.
Consider implementing coding tests as part of your software engineering interview process for candidates that have high potential or a specific skill set that's hard to assess with traditional interview questions. Exposing candidates to real-world constraints and letting them show their abilities will naturally lead to better hiring outcomes.
Want to look at programming test questions and answers that are specific to your open roles? Start a free trial with Woven today. Our coding interview platform allows you to build high-performing engineer teams with ease. We'll show you how!