Top 8 Technical Assessment Methods for Hiring Developers

March 21, 2025

Top 8 Technical Assessment Methods for Hiring Developers

Code Tests: Evaluate coding and problem-solving skills with tasks that reflect real job duties.
Technical Interviews: Dive deeper into technical knowledge and communication skills.
Project Assignments: Assess practical abilities through real-world projects.
Live Coding: Observe problem-solving and collaboration in real-time.
Past Work Analysis: Review portfolios or previous projects for insights into skills and growth.
Platform-Based Tests: Use tools like Codility or HackerRank for automated, scalable evaluations.
System Design Exercises: Test architecture planning, scalability, and trade-off analysis.
Code Reviews & Architecture Talks: Assess technical decisions and communication skills.

Why it matters:

75% of hiring decisions lead to mis-hires.
Bad hires can cost 5x the annual salary.
39% of recruiters rank technical assessments as crucial.

Quick Comparison of Methods

Method	Focus Area	Ideal For	Key Benefit
Code Tests	Coding skills	Entry-level roles	Predict job performance
Technical Interviews	Knowledge & communication	All experience levels	Test applied knowledge
Project Assignments	Practical skills	Mid-to-senior roles	Mimics job tasks
Live Coding	Problem-solving	All experience levels	Real-time collaboration
Past Work Analysis	Portfolio review	Experienced candidates	Validates real-world skills
Platform-Based Tests	Automated evaluations	High-volume hiring	Saves time with automation
System Design Exercises	Architecture planning	Senior roles	Tests scalability concepts
Code Reviews & Talks	Decision-making	Senior roles	Gauges strategic thinking

These methods, when combined, create a balanced hiring process that minimizes risks and ensures you find the right talent.

Tech Talks: Setting standards for your technical assessments

1. Code Tests and Problem-Solving Tasks

Code tests and problem-solving tasks are essential for assessing a developer's technical skills. Studies suggest these evaluations can predict job performance and ensure candidates meet the required technical standards.

A great example of an effective coding test comes from London-based Software Developer Zeno Foltin, who shared his experience with JUST EAT's recruitment process:

"I really liked the JUST EAT recruitment test because it is simple - list the takeaways for a given postcode using the API. It requires writing a simple UI to present the information, but it doesn't tell you much more on how to go about it. It is directly to do with their business, it covers UI and logic, and it requires more than a few minutes researching an algorithm. A well designed challenge, can give an opportunity for the candidate to showcase the best quality work that they can do without hard time constraints."

How to Make Code Tests Effective

To create meaningful coding challenges, focus on these aspects:

Relevance: Design tasks that reflect the actual work the role involves. For example, a debugging role could include identifying and fixing code errors.
Fairness: Use blind coding evaluations to minimize bias and apply tools like the Adverse Impact Ratio to maintain fairness.

Framework for Designing Code Tests

Component	Best Practice	Purpose
Time Limit	Flexible duration	Reduces stress while maintaining test value
Scope	Job-specific skills	Ensures relevance to the role
Instructions	Clear and concise	Helps candidates understand expectations
Evaluation	Multiple criteria (e.g., efficiency, readability)	Provides a well-rounded assessment

When reviewing submissions, go beyond basic functionality. Pay attention to code efficiency, problem-solving methods, critical thinking, and how maintainable the code is.

Tips for Entry-Level Positions

For junior roles, coding challenges are especially useful since candidates often lack extensive work experience. However, avoid overly complex algorithm-based tasks unless you're hiring for roles that require deep algorithmic expertise.

As noted by WeAreDevelopers, coding challenges are a great way to filter out candidates who lack the necessary technical and problem-solving skills, but they should be just one part of a broader evaluation process.

2. Technical Skills Interviews

After hands-on coding tests, technical interviews take it a step further by assessing a candidate's technical knowledge, problem-solving skills, and ability to communicate complex ideas. These interviews help gauge both expertise and how well candidates can apply their knowledge in practical situations.

Interview Structure Framework

Phase	Focus Areas	Time Allocation
Warm-up	Basic programming concepts	15–20 minutes
Technical Deep-dive	System design & architecture	30–40 minutes
Problem-solving	Real-world scenarios	20–25 minutes
Q&A	Candidate questions	10–15 minutes

This framework helps create a structured and balanced interview, combining technical challenges with a comfortable environment for the candidate.

How to Conduct an Effective Technical Interview

Balancing complexity with a relaxed setting is key to uncovering genuine expertise. Darío Blanco, Chief Technology Officer at KIRINUS Digital GmbH, highlights this:

"I strongly think that selection processes should be as flexible as possible to allow the candidate to perform without artificial pressure that is never really replicated in the work environment (who codes without an IDE of their choice after all?)"

Best Practices for Interviewers

Start Simple, Then Build Up
Begin with basic programming questions and gradually move into more complex topics like system design.
Focus on Problem-Solving, Not Just Answers
Daniel Seif emphasizes the importance of communication:

"The communication aspect of presenting a problem and discussing it with the interviewer is much more important than a particular programming style for us"
Use a Consistent Evaluation System
Develop a standardized scoring rubric to measure:
- Depth of technical knowledge
- Problem-solving strategies
- Clarity in communication
- Understanding of system design
- Awareness of code quality

Reducing Candidate Stress

Managing stress is crucial to ensure candidates perform at their best. For example, InterviewZen starts with simple tasks, like implementing a Fibonacci sequence, and gradually moves to more complex challenges, such as designing a real-time analytics dashboard.

Tips for Practical Assessments

Let candidates use their preferred IDE for live coding.
Ask scenario-based questions that align with your tech stack.
Clearly explain the interview structure ahead of time.
Document responses systematically for fair comparisons.

Remember, technical interviews should look beyond current skills to evaluate potential for growth. As Elmar wisely notes:

"Reassure the candidate that the entire 'interview' is about the journey the discussion takes - not necessarily the final answer. In fact, there is no right or wrong answer."

3. Project-Based Assignments

Project-based assignments mimic actual work tasks, allowing you to assess a candidate's practical abilities. Unlike coding tests or technical interviews, these assignments provide a closer look at how someone might handle real-world challenges on the job.

Framework for Designing Projects

Component	Requirements	Best Practices
Time Allocation	2–4 hours	Set clear deadlines and stopping points
Project Scope	2–3 core features	Focus on core functionality
Technical Stack	Common frameworks	Avoid niche or overly complex tools
Documentation	Clear specifications	Include coding standards and guidelines
Evaluation Criteria	Defined metrics	Share expectations ahead of time

Defining Clear Expectations

Clarity is key when assigning project-based tasks. Provide detailed instructions and realistic goals to ensure candidates understand what’s expected. Caleb Kaiser from AngelList Talent highlights the importance of these assignments:

"The major advantage of a take-home project, from a hiring perspective, is that you get to see what it would be like if candidates worked on your production code. The closer their project is to the real work you do, the better signal you'll get for how they'll contribute to your team."

Examples of Real-World Applications

Here are some ways companies integrate project-based assignments into their hiring process:

TuneIn: Offers a two-hour challenge with boilerplate code and a simple API to create a single-page application. This approach assesses key skills efficiently.
Workyard: Assigns front-end candidates the task of building a "Post a Project" modal in React, complete with Sketch files and detailed coding guidelines.
Frame.io: Tests candidates by having them improve an existing autocomplete search component, evaluating both maintenance and feature development skills.

What to Evaluate

Focus on key areas like technical execution, project management, and communication. Specifically, review:

Code quality and adherence to standards
How well the candidate managed their time within the given deadline
Clarity and thoroughness of their documentation

Compensating Candidates for Their Time

If the assignment takes more than four hours, consider offering fair compensation. This shows respect for the candidate's effort and time.

Best Practices for Reviewing Projects

When reviewing the completed assignment, pay attention to:

Architectural decisions and reasoning
Alternative solutions they might have considered
How they handled trade-offs due to time constraints
Suggestions for potential improvements

4. Live Coding Sessions

Live coding sessions are an engaging way to assess a developer's problem-solving approach and communication skills in real time. These sessions mimic everyday development tasks, offering a closer look at how candidates handle challenges in a practical setting. They also set the stage for further discussions about their problem-solving techniques and communication during follow-up exercises.

To make the experience smoother, ensure candidates are familiar with the session's format, tools, and the skills being evaluated. Let them use their preferred setup and programming language - this helps create a comfortable, collaborative environment similar to pair programming.

Today's live coding platforms come with features like collaborative code editors, built-in video and audio communication, code playback, and detailed evaluation reports. These tools help create a realistic coding environment that benefits both the interviewer and the candidate.

During the session, pay attention to:

How the candidate breaks down and tackles complex problems
The organization and quality of the code they write
Their ability to explain their thought process and decisions
How they react to feedback and adjust their approach

Create a supportive atmosphere by starting with simpler tasks and gradually moving to more challenging ones. The aim isn’t perfection - it’s about understanding their workflow and ability to produce functional code. This approach offers a more practical view of their development skills.

sbb-itb-fe42743

5. Past Work Analysis

Analyzing a developer's past work offers insights into their practical skills and growth over time. This approach goes beyond coding tests and interviews by validating their real-world experience. Reviewing a candidate's portfolio adds depth to your evaluation, highlighting their ability to apply skills in real projects.

When reviewing past work, focus on these three areas:

Portfolio Quality and Range

Look at completed projects that align with the role's requirements. Pay attention to the complexity, scope, and technology stack used. As Ihor Shcherbinin, VP of Recruiting at DistantJob, explains:

"A well-curated portfolio offers a window into a candidate's career path, showcasing their professional experiences and coding prowess through various projects".

Code Quality Indicators

Assess the following aspects to gauge the quality of their code:

Consistent naming conventions and organized structure
Clear and thorough documentation
Effective error handling and logging
Testing practices
Security and data privacy considerations
Performance optimization techniques
Commit history and frequency
Interactions during code reviews
Approaches to resolving issues

Community Engagement

Open-source contributions and participation in developer communities can reveal:

Collaboration skills with distributed teams
Ability to navigate and improve existing codebases
Willingness to share knowledge
Strong technical communication abilities

For a well-rounded evaluation, review both recent and older projects to track their professional growth. Look for signs of improvement in code quality, increasing project complexity, and adoption of updated development practices.

This assessment becomes even more effective when paired with technical discussions about specific implementation choices and architectural decisions. These conversations allow candidates to explain their reasoning and provide concrete examples of their expertise.

6. Platform-Based Code Tests

Platform-based code tests provide a standardized, automated way to evaluate developers' skills. These tools simplify the hiring process by offering automated grading and detailed reporting.

Modern platforms bring features that make these assessments even more effective:

Automated Grading: Instant feedback on performance
Realistic Coding Environments: Simulated workspaces that mimic real-world conditions
Multi-Language Support: Test candidates across various programming languages and frameworks
Plagiarism Detection: Ensure submissions are original
Proctoring Tools: Maintain secure and fair testing sessions

For instance, Chris Weber, Global Head of Recruitment, AI & Operate Solutions at Unity, shared that using Codility saved 2,200 hours of interview time in just 90 days.

Tailored Assessments

Many platforms allow tests to be customized for specific roles. Jon Senior, CTO at OpenGamma, highlighted the importance of realistic testing environments:

"So many testing platforms rely on the candidate writing code in a web-based interface, but this isn't realistic. CodeScreen lets candidates work on the test in the same way as they would develop software at OpenGamma."

Best Practices for Implementation

Clearly define metrics using consistent criteria
Use scenarios that mirror actual job tasks
Include a mix of multiple-choice questions and coding challenges
Set time limits that align with the complexity of the task

Impact on Hiring

These tools complement other assessment methods, making the hiring process faster and more efficient. Varun Berry, Managing Partner at Chordify, emphasized this benefit:

"When you have an assessment platform such as Mercer | Mettl, you have done your homework. You know the candidate is good enough. So you are saving time."

This method is particularly useful for high-volume hiring, where manual evaluations would be too time-consuming. By combining platform-based tests with traditional coding challenges and interviews, companies can create a scalable and thorough assessment strategy.

7. System Design Exercises

System design exercises, often done on a whiteboard, test a candidate's ability to design complex systems while explaining and defending their decisions. These exercises mimic situations where developers tackle unclear challenges to create workable solutions.

Core Areas of Focus

These exercises examine:

Architecture Planning: Breaking down systems into smaller, manageable parts
Scalability: Concepts like load balancing, sharding, and horizontal scaling
Problem-Solving Approach: Handling uncertainty and evolving requirements methodically

A Step-by-Step Evaluation

A well-structured system design exercise allows candidates to gradually demonstrate their skills. Daisy Modi, an Exponent coach and senior engineer with experience at Google, Uber, Adobe, and Twitter, advises:

"Concentrate on the basic principles of system design instead of memorizing particular product setups. Knowing the underlying principles will help you apply your knowledge to different situations and technologies, no matter the question."

Tailoring Complexity to Experience

The depth of the exercise should match the candidate's experience level:

Level	Focus Areas
Junior Engineers	Basic understanding and logical problem-solving
Senior Engineers	Advanced technical insights and trade-off analysis

Tips for Effective Evaluation

Suman B, an Exponent interview coach and Amazon engineering manager, highlights:

"I appreciate it when candidates show that they have considered multiple options to solve a problem. This broad understanding of different technologies shows me that they are not simply memorizing answers or the use cases of a single tech stack."

This structured process builds on earlier technical assessments, transitioning naturally into discussions about code review and system architecture.

What to Look For

Key criteria to evaluate include:

Understanding Requirements: How well candidates clarify and gather needs
Component Integration: Defining interfaces and communication protocols
Data Management: Decisions on storage and retrieval
Performance: Strategies to minimize latency
Fault Tolerance: Plans for reliability and handling failures

A strong system design interview highlights a candidate's ability to collaborate, stay calm under pressure, and handle ambiguity effectively. The goal is to assess how they think and approach problems, not just the final design. By focusing on reasoning and trade-offs, these exercises pave the way for deeper technical discussions.

8. Code Review and Architecture Talks

Code reviews and architecture talks are excellent ways to gauge both technical know-how and communication abilities. They complement earlier assessments by highlighting how candidates explain and justify their technical decisions.

Assessing Technical Skills

When reviewing a candidate's code, look at key factors like code quality, problem-solving, security awareness, performance, and documentation. Here's a breakdown:

Assessment Area	What to Look For
Code Quality	Is it readable, maintainable, and standards-compliant?
Problem-Solving	Are the solutions thoughtful and optimized?
Security Awareness	Can they spot vulnerabilities and follow best practices?
Performance	Is resource usage efficient? Can it scale?
Documentation	Are explanations clear? Are comments thorough?

The Role of Communication

"By developing your presentation skills, you are ensuring that you can effectively share your expertise and ideas with others - which is essential for your success."

Good communication is just as important as technical skills. In fact, studies suggest that non-technical abilities make up about 75% of an employee's success, compared to 25% for technical expertise.

Diving Deeper with Architecture Talks

Architecture talks go beyond code reviews by exploring a candidate’s strategic thinking. Key areas to focus on include:

System Understanding: Can they clearly explain complex systems?
Trade-off Analysis: How well do they justify their choices?
Future Planning: Do they have a vision for scalability and system evolution?
Collaboration: How effectively can they work with different teams or stakeholders?

Tips for Effective Assessments

Define Clear Goals: Make sure everyone knows what’s being evaluated.
Ask Open-Ended Questions: Encourage candidates to share their thought process.
Stay on Track: Keep discussions focused on the topic.
Observe Flexibility: Notice how candidates adapt to feedback or new ideas.

Remote Evaluation Tools

For remote assessments, tools like video conferencing, screen sharing, collaborative editors, and documentation platforms are invaluable. They not only test technical skills but also show how well candidates engage in team discussions online.

Conclusion

A strong technical assessment process combines technical tests with evaluations of soft skills. Together, these elements simplify hiring and help secure top-tier talent.

Building a Balanced Assessment Process

Stage	Assessment Method	Key Benefits
Initial Screening	Portfolio Review	Quick verification of skills
Technical Evaluation	Take-home Assignment	Solving practical problems
Final Assessment	Architecture Discussion	Analysis of strategic thinking

Impact on Hiring Success

Well-structured technical assessments lead to better hiring decisions. Research shows:

Top developers can be up to 400% more productive.
Labor costs often exceed 60% of corporate expenses.
A poor hiring reputation can raise cost-per-hire by at least 10%.

"These skills assessments save you a lot of difficulties on the line by demonstrating, beyond any doubt, that your stellar candidate has the skills and talent necessary to succeed."
– Peter Schoeman, Founder/CEO of The Dog Adventure

Creating Candidate-Friendly Assessments

To respect candidates' time and effort, focus on:

Clear and concise objectives
Familiar tools and practical scenarios
Providing prompt feedback
Maintaining open communication throughout

Future-Proofing Your Process

Collaborative teams can see productivity gains of 20-25%, highlighting the need to assess both technical skills and team compatibility. A thorough assessment strategy reduces hiring risks and helps build stronger, more cohesive development teams.

"To me, a good recruitment assessment tool should help us understand the person as a dynamic and complex human. It also should recognize that a person's ability to succeed in a role should look beyond just skills or experience. The X factor that somebody brings to work is in their human skills (what others might call soft skills), and you want a tool that measures for the X factor."
– Michelle Duval, CEO, Fingerprint for Success

From Blog

Let's have a coffee ☕️

Thank you! Your submission has been received!

Oops! Something went wrong while submitting the form.