The Simple Trick to Filter Out Average Developers Before the Interview

You've posted a job opening. Within 48 hours, you're drowning in 200+ applications. Most resumes look identical: "proficient in JavaScript, Python, and React," "strong problem-solving skills," "team player with excellent communication."

How do you separate the exceptional developers from the average ones without spending 40 hours on phone screens?

The answer isn't a complex algorithm or expensive screening tool. It's a simple, strategic filter that reveals who's genuinely invested in solving problems versus who's just mass-applying to jobs. Here's the one trick that will transform your hiring pipeline.

The Pre-Interview Assignment (Done Right)

Before you roll your eyes, this isn't about asking candidates to build you a free app or spend 20 hours on a coding challenge. This is about creating a smart, respectful filter that takes candidates 30-45 minutes but tells you everything you need to know.

The simple trick: Give candidates a small, relevant problem that mirrors real work they'd do on your team, and make the instructions deliberately open-ended.

Why it works: Average developers will do the bare minimum. Exceptional developers can't help themselves—they'll go beyond, ask clarifying questions, consider edge cases, and show you how they think. You're not testing their coding speed; you're testing their approach to problems.

How to Design Your Filter Assignment

The key is making it relevant, respectful, and revealing. Here's how to structure it:

1. Keep It Short But Meaningful

Time commitment: 30-45 minutes maximum

Complexity level: Something a mid-level developer could complete, but leaves room for excellence

Good examples:

• "Write a function that processes a list of customer transactions and identifies potential fraud patterns"
• "Create a component that displays real-time data with error handling"
• "Design a simple API endpoint that handles user authentication with rate limiting"
• "Debug this code snippet and explain what was wrong and why your solution is better"

Bad examples:

• "Build a full e-commerce checkout system" (too time-consuming)
• "Solve this LeetCode hard problem" (not relevant to real work)
• "Create our entire product feature" (disrespectful, asking for free work)

2. Make Instructions Deliberately Incomplete

Here's where the magic happens. Don't give them every single detail. Leave strategic ambiguities that require critical thinking.

Instead of:"Write a function that takes an array of integers and returns the sum. Use Python 3.9. Handle empty arrays by returning 0. Include type hints."

Try this:"Write a function that processes a collection of numbers and returns a meaningful result. Consider what might go wrong and how you'd handle it."

What you're observing:

• Do they ask clarifying questions before starting?
• What assumptions do they make, and do they document them?
• Do they consider edge cases you didn't explicitly mention?
• How do they handle ambiguity—common in real work?

Why average developers struggle: They wait for complete instructions. They do exactly what's asked, nothing more. They don't anticipate problems or ask "what if" questions.

Why exceptional developers shine: They ask thoughtful questions. They consider scenarios you didn't mention. They document their assumptions. They handle edge cases proactively.

If screening through hundreds of applications and evaluating assignments sounds overwhelming, RemoteEngine already has a network of vetted problem solvers who've been through this exact filtering process. You can skip straight to interviewing engineers who've proven they think beyond the bare minimum.

3. Evaluate the Thought Process, Not Just the Code

When reviewing submissions, don't just check if the code works. Look deeper.

What to evaluate:

Communication and documentation:

• Did they include a README or comments explaining their approach?
• Did they ask any clarifying questions via email?
• Can someone else understand their code without explanation?

Problem-solving approach:

• What edge cases did they consider?
• Did they make reasonable assumptions and document them?
• How did they structure their solution?

Code quality:

• Is it readable and maintainable?
• Did they follow best practices for the language?
• Are variable and function names meaningful?

Beyond the requirements:

• Did they add any thoughtful extras (tests, error handling, performance considerations)?
• Did they suggest improvements or alternative approaches?
• Do they show awareness of real-world implications?

Red flags that reveal average developers:

• Submitting code with no explanation or context
• Ignoring obvious edge cases (empty inputs, null values, invalid data)
• Copy-pasted code with irrelevant comments still included
• No error handling whatsoever
• Code that barely works for the happy path

Green flags that reveal exceptional developers:

• Clear documentation explaining their approach and assumptions
• Thoughtful questions asked before or during the assignment
• Error handling and input validation included unprompted
• Code that's readable and follows conventions
• Comments explaining "why" not just "what"
• Consideration of performance, security, or scalability even for simple tasks

For more insights on evaluating developer quality beyond just code, check out our guide on spotting great engineers without technical expertise.

The Implementation Strategy

Here's how to deploy this filter effectively in your hiring process:

Step 1: Send It Early

Include the assignment in your first response to applicants. Don't wait until after a phone screen.

Email template:"Thanks for applying! Before we schedule interviews, we'd like to see how you approach problems similar to what our team works on daily. Please complete this brief assignment (estimated time: 30-45 minutes) and return it within [3-5 days]."

Why this timing matters: Candidates who are genuinely interested will complete it. Those mass-applying to 50 jobs won't bother. You've just filtered out 60-70% of applications without spending any of your time.

Step 2: Make It Realistic

Base the assignment on actual work your team does. This serves two purposes:

1. Candidates get a realistic preview of the job
2. You see exactly how they'd handle real tasks they'll face

Example: If your team builds data dashboards, ask them to create a simple component that displays chart data with loading states and error handling. If your team works on APIs, give them a small endpoint design challenge.

Step 3: Respect Their Time

Be explicit about time expectations and compensation.

What to communicate:

• Estimated time commitment (be honest: 30-45 minutes)
• Clear deadline (3-5 days is reasonable)
• What you'll evaluate (thought process, not perfection)
• Confirmation this won't be used in production

Consider offering compensation: For assignments longer than 1 hour or more complex problems, offer payment ($50-100 is standard). This shows respect and attracts higher-quality candidates who value their time.

Never do this: Don't disguise real work as an assignment. Don't ask for solutions to your actual business problems. Don't use their code in production. This is unethical and will damage your reputation.

Step 4: Review Efficiently

Create a simple rubric so you can evaluate submissions quickly and consistently.

Sample rubric (score 1-5 for each):

• Code functionality (does it work?)
• Code quality (is it readable and maintainable?)
• Problem-solving approach (did they think beyond the basics?)
• Communication (did they explain their thinking?)
• Completeness (did they handle edge cases?)

Time investment: You should be able to review each submission in 10-15 minutes. If it takes longer, your assignment is too complex.

Threshold: Only interview candidates who score 4+ in at least three categories. This typically filters out 70-80% of submissions, leaving you with genuinely strong candidates.

For more strategies on efficient candidate evaluation, see our article on reviewing developer resumes without losing your mind.

Common Objections (And Why They're Wrong)

"Great developers won't do assignments. We'll lose top talent."

Actually, research shows that exceptional developers appreciate relevant assignments because it demonstrates you're serious about hiring well. What they hate are 10-hour projects or ridiculous algorithm tests disconnected from real work.

The key is making it short, relevant, and respectful. Top developers will do a 30-minute assignment that shows them what the job actually involves. They won't do busy work.

"This adds friction to our hiring funnel."

Yes, and that's exactly the point. You want friction that filters out the wrong candidates while letting the right ones through. Would you rather spend 30 seconds sending an assignment and 10 minutes reviewing it, or waste an hour on a phone screen with someone who can't code?

The friction eliminates tire-kickers and reveals who's genuinely motivated. Companies using this approach report 50-70% reduction in wasted interview time.

"We don't have time to review assignments."

You're already spending time on phone screens with unqualified candidates. This approach reduces those wasted calls by 70%. Ten minutes reviewing an assignment tells you more than a 30-minute phone screen where candidates can rehearse their answers.

Plus, you review assignments on your schedule. No calendar coordination required.

"Candidates will cheat or use AI."

Good. In real work, developers use Google, Stack Overflow, ChatGPT, and documentation. You're not testing their ability to code in isolation—you're testing their judgment about when to use resources and how to integrate them thoughtfully.

The follow-up interview is where you verify understanding. Ask them to explain their solution, modify it, or discuss alternatives. Cheaters will reveal themselves immediately.

Real-World Results

Companies implementing this simple filter report dramatic improvements:

Before the filter:

• 200 applications → 50 phone screens → 10 technical interviews → 2 offers → 1 hire
• Total time investment: 60+ hours
• Quality of final hire: hit or miss

After the filter:

• 200 applications → 60 complete assignments → 15 worth reviewing → 8 phone screens → 4 technical interviews → 2 offers → 1 hire
• Total time investment: 25-30 hours
• Quality of final hire: consistently higher

The time savings alone justify this approach, but the quality improvement is even more valuable. You're interviewing candidates who've already demonstrated they can do the work.

Taking It Further

Once you've mastered the basic filter, consider these advanced variations:

For senior roles: Include a code review component. Give them poorly written code and ask them to review it as if reviewing a junior developer's pull request. This reveals mentorship ability, communication skills, and depth of knowledge.

For leadership roles: Ask them to design a solution architecture or review a technical decision. Skip the coding and focus on strategic thinking.

For specialized roles: Tailor the assignment to specific technologies. React developer? Ask for a component. DevOps engineer? Ask about infrastructure decisions. Data scientist? Give them a dataset and a question.

The principle remains the same: create a quick, relevant filter that reveals how candidates approach real problems.

The Bottom Line

The simple trick isn't a secret algorithm or expensive tool. It's strategic friction applied at exactly the right moment in your hiring process.

By asking candidates to spend 30-45 minutes on a relevant problem before you invest your time, you:

• Filter out mass-appliers and unmotivated candidates
• Identify problem-solvers who think beyond the bare minimum
• Save yourself 30+ hours of wasted phone screens
• See exactly how candidates approach real work
• Create a better candidate experience for those who are serious

Average developers do what's asked. Exceptional developers can't help but go further. Give them the opportunity to show you which they are before you waste time in interviews.

Want to skip this filtering process entirely? RemoteEngine provides access to problem solvers who've already been vetted through comprehensive technical evaluations. Sometimes the smartest move is working with engineers who've already proven they think beyond the minimum requirements.

The best part? You'll know who's worth interviewing before you've spent a single minute on the phone. That's the power of a well-designed pre-interview filter.

Now go create your assignment and watch your hiring quality transform overnight.