Finding the right junior developer is akin to embarking on a treasure hunt. While you are obviously looking for someone who has a knack for coding, you’re also searching for a candidate capable of thinking critically, adapting to challenges, and displaying the potential for growth. But why is understanding their thought process so crucial? Let’s break it down.

The Anatomy of Good Programming: A Step-By-Step Journey

You might think programming is primarily about typing lines of code, but it’s much more nuanced than that. In reality, good programming follows a multi-step mental journey:

1. Understanding Requirements: Whether it’s through reading a project brief or listening to an oral explanation, the journey starts by absorbing the problem statement. It engages auditory and visual senses and requires focused attention to grasp the scope and particulars.

2. Initial Drafting: After absorbing the requirements, the next step is conceptualising a programmatic solution and drafting the initial code. This is where you can distinguish between programmers who dive in headfirst and those who take a moment to outline their approach.

3. Dry Running: Before proclaiming the code as final, it’s essential to test it against various scenarios. This dry run helps identify logical errors and pitfalls that might not be evident at first glance.

4. Peer Review and Edge Cases: No programmer is an island, and collaboration is key. Peer reviews often unearth overlooked edge cases and potential improvements. It’s where analytical thinking meets teamwork.

5. Collaboration and Communication: Sometimes, you need to go back to the drawing board. Whether you’re unclear about certain requirements or your solution needs refinement, effective communication with peers is pivotal. You’ll need to articulate your thought process clearly and also understand the perspectives of others.

The Multifaceted Skill Set

From this journey, you can see that programming isn’t just about writing code; it’s a symphony of skills harmoniously coming together. You’re using visual and auditory senses to grasp the problem, employing cognitive functions to map out solutions, utilising motor skills to code it, and leveraging communication abilities to explain, understand, or optimise your approach.

Why The Thought Process Matters

Understanding a junior developer’s thought process allows you to assess this diverse skill set. It helps you judge not only their coding abilities but also their potential to engage in analytical thinking, problem-solving, teamwork, and effective communication — skills that are indispensable in the real world of software development.

This comprehensive perspective forms the cornerstone of my interviewing approach. It ensures that I’m not just hiring someone who can code today but someone who has the potential to be a valuable team member for years to come.

Example 1: Summing Digits in a String

We’ve already discussed the first example, summing numbers in a given string, separated by commas like “12,141,4,5235,2,3,5”. I use this to assess basic problem-solving skills and attention to detail.

Common Mistakes

• Ignoring non-numeric characters

• Inefficient algorithms

• Failure to check for errors or exceptions

What It Reveals: The Value of Mistakes

For many interviewers, a mistake in coding might be a red flag. For me, it’s an opportunity. You see, mistakes, especially in a pressure-cooker situation like an interview, are inevitable. What’s more important is how candidates handle those mistakes when they’re brought to light.

After reviewing the code, I make it a point to discuss any errors or oversights with the candidate. Rather than pointing out the mistakes explicitly, I offer hints or ask questions aimed at guiding them toward identifying the issues themselves. This approach serves multiple purposes:

1. Understanding Thought Process: Their mistakes, and more importantly how they address them, give me a window into their thought process. Do they backtrack efficiently to spot the error, or do they get stuck in a loop of confusion?

2. Problem-Solving Skills: Can they figure out and fix their mistakes when prompted? This ability to self-correct is a crucial skill for any developer and an indicator of how they might handle real-world debugging tasks.

3. Receptivity to Feedback: How do candidates react when their errors are exposed? Do they become defensive, try to pass the buck, or make excuses? Or, do they acknowledge the oversight and take constructive criticism well? Their reaction gives me valuable insights into their maturity and professionalism, which are critical for team dynamics.

In short, it’s not the mistakes themselves but how they are addressed that reveals the true caliber of a junior developer. This method allows me to assess not just their technical skills but also their problem-solving abilities and emotional intelligence. Both are key factors in determining whether a candidate will be a long-term asset to the team.

Example 2: Identifying Overlapping Appointments in a Doctor’s Schedule

Scenario

Imagine you’re tasked with building an appointment scheduling system for a busy doctor’s clinic. You have an array of startTime and endTime objects representing booked appointments. Your objective is to identify any overlapping time slots in order to avoid double-booking the doctor.

Plain textANTLR4BashCC#CSSCoffeeScriptCMakeDartDjangoDockerEJSErlangGitGoGraphQLGroovyHTMLJavaJavaScriptJSONJSXKotlinLaTeXLessLuaMakefileMarkdownMATLABMarkupObjective-CPerlPHPPowerShell.propertiesProtocol BuffersPythonRRubySass (Sass)Sass (Scss)SchemeSQLShellSwiftSVGTSXTypeScriptWebAssemblyYAMLXML const appointments = [ { startTime: "09:00", endTime: "10:00" }, { startTime: "09:30", endTime: "10:30" }, { startTime: "11:00", endTime: "12:00" }, { startTime: "11:30", endTime: "12:30" },];

Common Mistakes

1. Not accounting for edge cases, such as appointments that start and end at the exact same time.

2. Using inefficient algorithms that don’t scale well when the number of appointments grows.

3. Failing to validate the input times, assuming they are always correctly formatted.

What a Smart Approach Looks Like

It is interesting how candidates try to solve the problem. A candidate might start by sorting the array by startTime and then iterate through the sorted array to find overlapping times or could use a sliding window approach or a simple loop that checks if the endTime of the current appointment is greater than the startTime of the next appointment.

This exercise can also serve as a platform for the candidate to discuss their understanding of time complexity, efficient algorithms, and their rationale for selecting a specific approach.

This real-world example will challenge candidates to think critically, allowing you to better assess their problem-solving and coding skills.

Example 3: The Optional, Tough Challenge — Travelling Salesman Problem (TSP)

This is an optional bonus question and is not intended to be a mandatory part of the assessment. The candidate is welcome to skip this question if they find it too challenging. Attempting this problem will give us additional insights into their problem-solving skills, but it’s not a requirement.

This way, candidates have the freedom to decide whether they’d like to attempt the problem, without feeling pressured to solve it. Making it optional removes the stress, while still providing an opportunity for those who want to showcase more advanced skills.

The Scenario

Picture this: You’re developing a delivery management system for a logistics company. The company wants to minimise fuel costs by finding the shortest possible route that visits a set of cities exactly once and returns to the original city. Welcome to the classic Travelling Salesman Problem (TSP) — a problem that is computationally intensive and has a long history in computer science.

The Task

The candidate is asked to find the shortest path that visits all given cities exactly once and returns to the starting city. The candidate has to write a function that takes an array of cities and the distances between each pair as input, and returns the shortest possible total distance.

Plain textANTLR4BashCC#CSSCoffeeScriptCMakeDartDjangoDockerEJSErlangGitGoGraphQLGroovyHTMLJavaJavaScriptJSONJSXKotlinLaTeXLessLuaMakefileMarkdownMATLABMarkupObjective-CPerlPHPPowerShell.propertiesProtocol BuffersPythonRRubySass (Sass)Sass (Scss)SchemeSQLShellSwiftSVGTSXTypeScriptWebAssemblyYAMLXML // Sample input: Distances between citiesconst distances = [ [0, 29, 20, 21], [29, 0, 15, 17], [20, 15, 0, 28], [21, 17, 28, 0]];

What This Bonus Question Reveals

1. Courage and Confidence: Attempting this question reveals a candidate’s willingness to tackle complex problems, even when they’re marked as optional or bonus.

2. Stress Management: Under the pressure of an interview, even contemplating a question like this can be nerve-wracking. How they handle this can be insightful.

3. Analytical Depth: While I don’t expect a perfect solution or even a solution, the approach taken to even attempt this problem shows how deeply a candidate can think through a complex issue.

Why It’s Okay Not To Solve It

To be clear, my expectation is not that junior-level candidates will solve this problem within a limited timeframe. In fact, even experienced developers might struggle with it. The very act of attempting it, however, speaks volumes about the candidate’s character and problem-solving ethos.

Sometimes, the most telling actions are the ones taken when the odds are stacked against you. If a candidate attempts this problem, it’s an encouraging sign that they have the audacity to confront challenges head-on, that they’re not afraid to make mistakes, and that they’re willing to step out of their comfort zone. These are invaluable traits that can’t always be assessed through simpler tasks.

Adding this “bonus” challenge into the mix provides a comprehensive evaluation mechanism, rounding out my understanding of a candidate’s technical skills, courage, and problem-solving abilities.

The Bigger Picture: Beyond Just Coding Skills

While coding abilities are undeniably crucial for any software development role, they’re not the only yardstick for measuring a candidate’s suitability, especially when hiring junior developers. In fact, a comprehensive understanding of computer science and a curiosity about the ever-evolving tech landscape can be equally telling indicators of a candidate’s potential. So, how do I evaluate this broader know-how?

The Non-Coding Questions

Apart from the coding tests and challenges, I also ask a series of general computer science and tech industry questions to gauge the candidate’s overall engagement with the field. These questions could range from:

1. Artificial Intelligence: “Have you ever used any AI-based tools for code generation or evaluation?”

2. Emerging Tech Trends: “What do you know about the metaverse, and how do you think it could impact software development?”

3. Hardware Knowledge: “What is the difference between a micro-controller and a micro-processor?”

4. Web Architecture: “Can you explain what a Content Delivery Network (CDN) is?”

The Objective

The purpose behind these questions isn’t to conduct a quiz but to gauge the candidate’s overall engagement and enthusiasm for computer science and technology. These questions help me discern:

1. Awareness Level: Even if the candidate doesn’t know the answer, their willingness to guess or piece together an answer from what they do know can be revealing.

2. Readiness to Learn: Junior developers are, by nature, works in progress. Their approach to these questions can indicate how teachable they are. Are they defensive when they don’t know something, or are they eager to learn?

3. Passion for the Field: Someone who keeps tabs on the broader landscape of software development often brings more to the table than just coding skills. They bring a contextual understanding that can be invaluable as they grow into more responsible roles.

Why This Matters

Remember, the goal isn’t just to hire someone who can contribute today but to bring on board someone who can grow and evolve with the team and the industry at large. An awareness of broader computer science concepts and industry trends indicates that the candidate isn’t just looking for any job — they’re looking for a career in software development.

A Note to Prospective Candidates and Curious Minds

You might be wondering, “If she is disclosing all her interview secrets, what’s left for the actual interview?” To that, I have a straightforward answer: If you’ve read this far and absorbed the insights, you’re already the type of candidate I’m interested in. Understanding and performing well based on the guidelines outlined in this article shows not just your technical acumen but also your dedication to preparation and continuous learning. So, if you’ve reached this point, congratulations! You’re exactly the kind of candidate who thrives in a challenging, growth-oriented environment like ours. Don’t hesitate — send me your CV today. The journey towards excellence is often hidden in plain sight, and you’ve just taken the first step. Beware: the above coding challenges are not the exact ones that I ask, instead, I pick from a pool of such questions.

By now, you should have a vivid picture of what it takes to not just hire a junior developer, but to bring onboard a true asset to your team. Remember, it’s not solely about coding chops or technical expertise, but an amalgamation of diverse skills and character traits that foster growth, both for the individual and the organisation. Hiring is not a transaction; it’s an investment in your company’s future. Therefore, scrutinizing the multifaceted nature of a candidate’s abilities can provide you with invaluable insights into their long-term potential. So the next time you find yourself looking through a stack of résumés or conducting interviews, keep in mind that you’re not just evaluating candidates for today but discovering the leaders and innovators of tomorrow.

Happy hiring!