The Tech Interview Behind the Scenes: Georgi Nastev

The Tech Interview Behind the Scenes is an HRLabs series.
Let’s take a look behind the scenes of the technical interview process from the interviewers' perspective.
Our goal is to provide candidates with valuable tips and recommendations directly from professionals who conduct interviews for various technical roles.

“Candidates with strong communication skills have a clear advantage over others.” shares Georgi Nastev, co-founder & CTO at EnergyGlare.

Tell us more about your career path.

The choice of education naturally led to a career in the IT sector. It all started about 20 years ago when I was a student at the Technical University of Sofia. In my third year, I began working as a junior developer at an outsourcing company, which was my first exposure to professional programming and the industry as a whole.

Shortly after, I joined a great Bulgarian company, Nemetschek Bulgaria, where I spent nearly seven years as a software engineer. It was an excellent place to build strong technical knowledge and gain solid experience. Thanks to the entrepreneurial and investor spirit of the company’s owner, Georgi Brashnarov, internal competitions for new ideas were organized. Participating in these initiatives helped me see the bigger picture of software product development—what it takes to create a product rather than simply executing a task.

Later, I moved to Scalefocus, where we first met (*met Radoslava Dimitrova). Initially, I started as a team lead for one of the company’s U.S.-based clients. At that time, the company was focused on aggressive growth, with an almost constant hiring stream. A year later, Scalefocus went through a restructuring, organizing teams based on technology expertise.

I was appointed as the head of the Frontend, UX/UI, and PHP divisions (with PHP later becoming a separate unit). We started with a small team of about 10 people, but as the company grew and web development gained popularity, our unit expanded organically from 30+ to over 90 people within two years. Eventually, we acquired a smaller company, and our team grew to about 120-130 people.

This growth also involved geographical expansion, opening new offices in different cities across Bulgaria. As a result, I had to shift my focus toward People Management, building internal structures for team organization, training programs, career path development, and defining job roles. During this period, alongside other senior colleagues, I participated in hundreds of interviews with candidates and subcontractors from different countries. The company's fast-paced nature also required me to be involved in pre-sales initiatives, client discussions, and proposal development.

As Scalefocus continued expanding, we restructured the management framework to better distribute responsibilities and optimize leadership efficiency. This was the moment I realized that I was more interested in solving business challenges through technology. That’s when I transitioned into Delivery Management, where the focus shifted to business relationships, organizational and/or technical leadership of client projects. I spent nearly eight incredible years at Scalefocus, growing alongside an amazing team of professionals.

In the first half of 2024, I decided to push forward a startup idea that my friend and I had been shaping for a while. We founded a startup company in Hong Kong called EnergyGlare. We developed a platform for investing in decarbonization and energy efficiency projects, integrating all key roles involved in such projects and structuring their interactions based on a digital version of ESCO contracts. The platform tracks project development from inception through investor onboarding, deployment, and investment repayment, offering unique advantages to all stakeholders. We are now on the verge of onboarding our first users.

As a candidate, have you had any strange interviews? What about interviews that impressed you?

I can’t recall any particularly strange interviews, but the most unusual approach I’ve ever experienced for an interview invitation happened more than 10 years ago.

One day, a gift basket filled with various delicious treats arrived at the reception desk of the company where I was working at the time. It was addressed to me, but there was no sender—just a short note that I don’t remember now. A week later, a second basket arrived, this time containing a flash drive with a company logo on it. The flash drive had a task on it and an email address where I was supposed to submit my solution. I hadn’t applied for any job, nor was I actively looking for a new position, so I never responded.

I can think of two interview processes that impressed me in different ways. Both were early in my career, after I had gained a few years of experience, and I later incorporated elements from them when structuring my own interviews.

The first was with VMware. I applied for a junior position, but the process involved 10 diverse interviews spread over three days. The first two days lasted about three hours each, while the final one took around four hours. It was an intense and exhausting experience, but also highly engaging.

The second was for a Microsoft position in Denmark. It started with a phone screening, followed by three on-site interviews in Denmark. Microsoft wasn’t strictly focused on specific technologies; instead, they were interested in seeing how candidates think and approach practical problem-solving.

What skills and qualities do you look for in a candidate? How can a candidate stand out during the interview?

When it comes to software engineering candidates, the required skills and qualities vary significantly depending on the specific position and level. The key attributes that make a junior candidate stand out differ from those expected at a senior level.

The less experience a candidate has, the more important their technical knowledge, willingness to learn, and commitment to the new role become. A solid understanding of technological concepts, algorithms, data structures, protocols, and design patterns is crucial. While these may not be applied directly in everyday work, studying and understanding them shapes a candidate’s problem-solving mindset, approach to structuring and implementing applications, and overall professional development. At this stage, a key question should be: “How do applications and software services work?”

Beginners often focus on a specific programming language, learning its unique features and foundational concepts. While modern development relies on bootstrap tools and frameworks, understanding the underlying processes they automate is still beneficial in the long run.

As experience grows, expectations shift towards a deeper understanding of design patterns, active participation in development tasks, independence, and initiative in proposing solutions to daily challenges. At this stage, it’s not just about knowing a programming language, but also about using libraries, frameworks, cloud infrastructure services, testing practices, and deployment processes.

At even more senior levels, candidates are expected to demonstrate a higher degree of professionalism, both in technical implementation and responsibility. This includes architectural design, well-established solutions tailored to business needs, performance optimization, and ensuring the security and stability of applications to meet non-functional requirements and handle increased workloads.

More experienced candidates typically have a clear understanding of the role they’re applying for, their own expertise, and the company they are interviewing with.

For me, how a candidate has acquired their knowledge—whether through university education or career transition from another field—is not what matters most. There are excellent academies that enable people to retrain as software engineers, and I’ve worked with outstanding professionals from both academic and non-traditional backgrounds. However, academy training often provides broad but shallow knowledge, aimed at quickly getting candidates into the job market. To be successful in the long run, they need to deepen their understanding of core concepts.

Finally, I want to highlight the importance of non-technical skills. Communication skills are crucial and, in some cases, can even outweigh technical expertise when making hiring decisions. In software companies providing services to external clients, the ability to communicate effectively and integrate into different teams is essential.

The COVID-19 pandemic accelerated the shift towards distributed teams, where members are not physically in the same room. This placed a stronger emphasis on team communication, proactiveness, engagement, and clarity in interactions. In my experience, these skills are just as valuable as technical proficiency—especially in senior roles, where leadership responsibilities come into play. Candidates with strong communication skills have a clear advantage over others.

What questions do you typically ask in technical interviews? Do you have specific tasks or problems that you often use to assess candidates?

When conducting interviews, I always prepare in advance, tailoring the process based on my role and the position the candidate is applying for.

I usually start with an introduction, explaining the purpose of the interview, what the company does, and what we’re looking for. Then, I let the candidate take the lead, asking them to share their experience. It’s important for me to hear, in their own words, about the projects they’ve worked on, their responsibilities, and their role within the team.

Different candidates approach this differently depending on their seniority. I often ask clarifying questions to understand their level of involvement—did they just write code mechanically, or did they understand the bigger picture? Were they part of decision-making and discussions, or just following instructions? The way a candidate reflects on their work and engages in the process sets them apart. Writing code is no longer the differentiator—it’s the added value a developer brings. A simple coding question can be answered with a quick AI query, but critical thinking and meaningful contribution cannot be replaced.

I then move on to core technical topics, tailored to the specific technology stack. Again, I’m not looking for textbook definitions—those can be found on Google—but for practical understanding and application.

I also include real-life challenges from past projects as interview questions. There’s often no single correct answer, but I want to see how the candidate thinks and approaches problem-solving based on their experience.

One large international tech company I partnered with had a great way of assessing depth of knowledge. They would ask a seemingly simple question:

“What happens when you type a URL into a browser and press Enter?”

The depth of the response would reveal how well the candidate understood the underlying technologies.

From my experience, live coding exercises during interviews don’t add much value, so I don’t use them as an evaluation method.

How important are good communication skills for a candidate? How do they impact the overall interview?

For me, communication skills are extremely important. Especially in a service company, where colleagues are often remote members of external teams. In such cases, communication is just as crucial as technical knowledge—which can be easier to catch up on.

Working on projects across different countries or even continents also requires interacting with diverse people, further emphasizing the need for strong communication skills.

Moreover, if you're a job candidate, a lack of communication skills could distance you from great opportunities.

How important is cultural fit when making a hiring decision? How do you assess whether a candidate will fit well into the team?

This is an interesting and very important question. As a Delivery Manager, the teams I have formed for various projects often consist of diverse individuals, and it's crucial for team members to work well together to achieve their goals.

In addition to that, I have also worked with people from other companies as well as different countries. Being part of Scalefocus, which has expanded with additional development centers in North Macedonia and Turkey, the geographical principle of team formation became irrelevant—unless it was a strict requirement for a specific project. Very often, our teams have been blended with others from North America, Europe, and the Middle East.

With such a rich mix of cultures, it became important for me to include screening questions related to a candidate's ability to integrate into an international team. For example, how they would feel working in an environment where communication happens in a non-native language, how they handle intercultural differences, and how they would react to misunderstandings within the team.

I try to understand their personal boundaries in advance and align them with the project’s environment. By prioritizing the professional context, discussing potential challenges with candidates clearly and directly, it becomes easier to assess whether cultural differences would have an impact and how.

Of course, this hasn’t always worked seamlessly. There have been cases where team adjustments were needed to ensure better alignment between people.

What are the most common mistakes candidates make during an interview? What advice would you give candidates on how to prepare for an interview?

It’s not uncommon for candidates to be unprepared for where they are going for an interview. The dynamics of product and service companies are different, which also defines differences in the hiring process. Companies often have different interview approaches based on their specific needs. What works in one company might not work in another.

When applying for a job, it’s useful to ask about the interview process—what types of meetings will take place, what aspects will be emphasized. Based on that, candidates can better prepare for the specific company. Often, information can be found from friends or publicly available sources about the company. While this can be helpful, keep in mind that opinions are often subjective and may not align with your own perceptions.

Interviews are a form of presentation. Reviewing your resume in advance, deciding what you want to highlight about yourself, which aspects to emphasize, and recalling past projects and achievements can help structure your thoughts during the interview. This will reduce nervousness and project confidence.

What advice would you give to candidates who want to improve their technical skills? Are there any resources you would recommend?

Lately, I've been a huge fan of learning new things and keeping up with trends on YouTube. Many leading figures and companies share their latest updates through their channels, and there are also well-structured, popular channelsdedicated to tracking trends in specific fields. Many companies stream their tech conferences live on YouTube, or the videos quickly become available afterward.

I often don't have the time to read an entire article or book. In such cases, I use AI-powered tools to summarize content or help me find the information I need by asking questions. In my opinion, this completely changes the approach to learning. AI chat tools allow you to start somewhere and expand your understanding in any direction you want, without needing to open a new book or have deep prior knowledge of a subject. There are even specialized models fine-tuned for specific topics.

Nowadays, there’s nothing people can't learn—as long as they want to.

Share more about the best (or worst) interviews you've conducted.

I don’t have a personal ranking. The interviews that have left the most negative impression were definitely those where candidates clearly had no interest in being there—the conversation was extremely difficult, answers were one-word responses, and in some cases, I even encountered passive-aggressive behavior. After 15-20 minutes of unsuccessful attempts to have a meaningful conversation, it becomes obvious that there’s no point in continuing. These interviews end up being a waste of time for both sides. I’ve often wondered why people even schedule interviews with such an attitude, but I still don’t have an answer.

Looking back, I’ve had the chance to interview many great candidates, and I’ve worked with many of them later on. It’s hard to pick the absolute best. In many cases, people grow significantly over time, even if their interviews weren’t particularly impressive.

One of the most memorable positive experiences I’ve had was a series of interviews with candidates from three South American countries—Peru, Colombia, and Venezuela. It served as a great reminder not to form premature opinions. I initially had low expectations, but I was pleasantly surprised to find that the candidates had excellent knowledge and solid experience. On top of that, they were able to communicate fluently in multiple languages.

How do you evaluate a candidate during an interview—based solely on their theoretical knowledge, or is their approach to solving a problem/task more important to you? What other factors do you consider when making a decision?

In addition to theoretical preparation, I assess how candidates approach problem-solving and reasoning. I also evaluate how they communicate, work in a team, and fit into the specific context for which they are being interviewed.

What would you like candidates to know about the interview process in your company? What could be useful for them in their preparation?

As of today, working on my own early-stage startup, my focus is spread across different areas, not just technology. There are also different budget considerations compared to larger companies.

I can share a few examples. Some of the tasks we've worked on have been handled by freelancers with short-term engagements and clearly defined tasks and goals. The interview process in such cases is direct, with clear expectations and success criteria. The technical or thematic questions are tailored specifically to the task at hand.

For example, when we worked on UX/UI design, we collaborated with a designer from Pakistan. The expectations were for her to explain her previous experience related to our type of application, her design process, and workflow, and to discuss our specific goals while presenting her approach to achieving them.

Some smaller pieces of code were developed with developers from India. For these tasks, the requirements were focused on specific web technologies, such as building React components, handling data processing, and formatting it according to predefined structures.

We worked on monetization strategy, tokenomics, and pricing for our blockchain token together with brilliant senior-year students from an Australian university. The expectations for them included strong theoretical knowledge of the topics, research and comparative analysis skills, and an understanding of certain legal and business concepts. As a result, they created a foundational document that could compete with work done by established consulting firms.

Share a funny story from your experience as an interviewer :)

I remember one interview that turned out to be quite comical because of the candidate’s setup. He was from Pakistan and had laid down in bed, wrapped in a blanket, resting his head on one hand. His device was placed on some kind of stand next to the bed, giving a clear view of a large part of the background.

I wasn’t expecting this setup, so I couldn’t help but smile. We clarified that this was simply how he felt most comfortable, and we moved forward with the interview. However, he didn’t have the necessary knowledge, so the conversation didn’t last long.