The Tech Interview Behind the Scenes: Stanimir Feradov
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.
“Qualities I value most in candidates are honesty and transparency.” shares Stanimir Feradov, Lead Solution Architect at Costa Coffee.
Tell us more about your career path.
I have been passionate about computers and their inner workings since high school, spending my free time exploring hardware, studying how it functions, and keeping up with the latest innovations in the industry. I also completed online courses in professional malware removal, which enabled me to assist over 100 people worldwide while I was still in high school.
After six years in sales, I decided to transition back to my passion—this time focusing on software development. A year and a half later, I began my career at a small company where I had the privilege of working alongside exceptional professionals who inspired me with their commitment to continuous learning and deep technical understanding.
Since then, I have contributed to a wide range of projects, from large CRM systems to IoT platforms and enterprise-scale solutions, primarily working with Microsoft technologies (.NET and Azure).Throughout my career, I have taken on various roles, including full-stack engineer, team lead, tech lead, and solution architect, allowing me to develop a well-rounded perspective on software development and system design.
I have participated in several side projects that have put the foundations for promising startups and I have built several solutions that continue to simplify the business processes of number of large organizations.
As a candidate, have you had any strange interviews? What about interviews that impressed you?
Fortunately, I haven’t encountered many strange interviews, though a few have left a lasting
impression. One that stands out was a live coding session where the interview began with a brief introduction—less than a minute—before jumping straight into coding. I was required to write code remotely on another person's PC, which had significant lag and stuttering issues, making the entire experience frustrating. Despite repeatedly mentioning that I couldn’t see half of what I was typing due to the delay, I did my best to complete the task. As expected, I didn’t pass the interview, but what stood out the most was the complete lack of engagement—it never felt like I was interacting with real people.
On the other hand, the most impressive interview I experienced was for a company where I later worked for nearly two years. The process consisted of three main steps with five distinct stages, combining both cultural fit and technical assessments. The final stage was particularly memorable, as it blended solution design with live coding. During this session, we discussed various architectural options, analyzed challenges in the initial solution, and explored how to adapt it to accommodate new scenarios. It was a fantastic learning experience, and at every moment, it felt like a genuine technical discussion with a colleague rather than a one-sided evaluation. This approach demonstrated the company’s commitment to hiring problem solvers rather than just developers who can write code.
What skills and qualities do you look for in a candidate? How can a candidate stand out during the interview?
I have always valued candidates who focus on solving problems through technology rather than simply writing code. In my view, software engineering shares many similarities with art -we are craftsmen who apply patterns and styles to address challenges. However, we are not confined to these approaches; we always have the flexibility to explore alternative solutions that better fit the situation. Individuals with a problem-solving mindset embrace challenges, seek efficiency, and strive to develop simple yet effective solutions.
What makes a candidate stand out is a combination of open-mindedness, a willingness to challenge ideas, and a strong desire for continuous learning. The ideal candidate is not afraid to make mistakes but instead views them as learning opportunities. They should articulate their thought process, engage in meaningful discussions, and actively seek to understand concepts that are unclear to them. Demonstrating curiosity, adaptability, and a proactive approach to problem-solving sets them apart from the rest.
What questions do you typically ask in technical interviews? Do you have specific tasks or problems that you often use to assess candidates?
The questions and tasks I use in technical interviews depend on the candidate and the role they are applying for. However, my general approach is to foster a discussion rather than simply evaluating answers. I start with fundamental topics and gradually introduce complexity through follow-up questions. This method helps guide the candidate’s thought process, empowers them to think critically, and provides additional context to support them during the interview.
As the discussion progresses and the candidate becomes more comfortable, I introduce more
advanced questions—primarily to assess the depth of their knowledge. However, I always ensure that the questions remain grounded in real-world scenarios.
The technical assessment is typically a balanced mix of framework- or language-specific topics and broader design patterns or architectural principles. The proportion of each depends on the candidate’s background and prior experience, allowing for a tailored and meaningful evaluation.
How important are good communication skills for a candidate? How do they impact the overall interview?
Communication skills are one of the most essential qualities in a candidate. As mentioned, modern software development is no longer just about designing and writing code in isolation—it almost always involves collaboration within teams of varying sizes and structures. Additionally, communication with business stakeholders is becoming increasingly important for developers at all levels of experience.
A candidate with strong communication skills can more effectively collaborate with colleagues across different projects and adapt to various circumstances. They can clearly articulate potential issues, contribute effectively in critical situations, and foster teamwork. Moreover, strong communicators are better equipped to mentor others, explain their ideas with clarity, and support discussions with concrete examples drawn from their own experiences.
With the rise of AI-driven development tools, the role of software engineers is evolving toward a more supervisory capacity. In this shift, the ability to clearly define objectives, express ideas concisely, and provide meaningful direction will be crucial in maximizing productivity and driving a greater impact within teams.
How important is cultural fit when making a hiring decision? How do you assess whether a candidate will fit well into the team?
For me, a candidate’s cultural fit is the an important factor, yet it is often overlooked. Even highly skilled individuals with exceptional technical expertise can have a minimal or even negative impact on a team's velocity and cohesion if they do not align with the team’s culture.
The key indicators of a strong cultural fit include a desire for continuous learning, the ability to accept and act on feedback, a willingness to challenge ideas constructively, openness to new perspectives, and a commitment to team success. Through discussions and questions based on past experiences, candidates can often demonstrate whether they have exhibited these qualities in previous roles.
What are the most common mistakes candidates make during an interview? What advice would you give candidates on how to prepare for an interview?
Interviews are a complex process, and there are several common mistakes that candidates make many of which leave a lasting negative impression on interviewers, myself included.
One of the most basic yet frequent mistakes is arriving late or failing to notify the interviewer if you cannot attend at the scheduled time. Candidates should always remember that interviews are a two-sided process, and any lack of professionalism from one party affects the other. Respecting the interviewer's time is a crucial aspect of leaving a positive impression.
Another common pitfall is inadequate preparation. Preparation extends beyond simply refreshing technical knowledge—it also involves researching the company and preparing thoughtful questions. Candidates should inquire about aspects such as team structure, collaboration processes, opportunities for self-learning and career growth, performance review cycles, and company goals. This is particularly important for product companies or those in an early stage of development, where understanding the bigger picture can be beneficial.
Additionally, many candidates fall into the trap of treating the interview as a rigid Q&A session rather than engaging in a meaningful discussion. While stress is a natural part of the process, it is important to mitigate its impact. If a candidate is unsure of an answer, it is far better to articulate their thought process, explore potential solutions, and reason through possibilities rather than remaining silent or giving a quick, dismissive response.
Closely related to this is the importance of challenging assumptions and seeking clarity. When faced with complex or ambiguous questions, candidates should confirm their understanding before responding—this can be as simple as rephrasing the question to ensure alignment. Not only does this help the candidate process the question correctly, but it also demonstrates strong analytical skills and attention to detail.
Furthermore, candidates should observe whether interviewers seek feedback at the end of the
session. Since interviews are a two-way process, good interviewers will often look for ways to
improve their approach. Providing constructive feedback can be a sign of engagement and
professionalism.
Lastly, candidates should not hesitate to end an interview early if the other side appears
unprofessional or disengaged. Your time is valuable, and interviews should be a meaningful exchange rather than a one-sided interrogation. If the interviewers seem solely focused on identifying weaknesses rather than assessing strengths, it may be a sign that the company’s culture is not the right fit.
What advice would you give to candidates who want to improve their technical skills? Are there any resources you would recommend?
Throughout my career, my primary focus has always been on building a strong foundation in computing and understanding how large-scale systems function. A solid grasp of computer
fundamentals provides the necessary context for tackling more advanced topics.
The next essential step is mastering data structures and algorithms, as they form the backbone of modern software development. Once these fundamentals are in place, moving on to higher-level concepts such as design patterns and integration patterns is crucial, as they are integral to building scalable and maintainable systems.
I strongly advocate for the T-shaped developer model—specializing in a particular tech stack while maintaining a broad understanding of other technologies. Being deeply proficient in a specific stack allows a developer to solve complex problems efficiently, while familiarity with one or two additional programming languages, especially those based on different paradigms, expands problem-solving capabilities and decision-making skills. A deeper understanding of a chosen tech stack fosters confidence and adaptability in real-world scenarios.
When it comes to learning resources, I have always preferred books that focus on core principles rather than framework-specific implementations. Technology evolves rapidly, so understanding fundamental concepts—such as how garbage collection works at a high level—is far more valuable than memorizing syntax or framework-specific features. The latter may change frequently, but the former remains relevant across multiple platforms.
More recently, I have found select YouTube channels useful for keeping up with industry trends and updates. However, I tend to avoid content creators who focus primarily on hyped topics, as these often revolve around long-established patterns or minor syntactic enhancements without providing meaningful depth. Instead, I prioritize resources that explain the underlying mechanisms of technologies, ensuring a more comprehensive and long-term understanding.
Share more about the best (or worst) interviews you've conducted.
The best interviews I have conducted have always taken the form of discussions rather than rigid Q&A sessions. A strong candidate is not necessarily the one with perfect recall of a language or framework but rather someone who demonstrates the ability to think critically and search for effective solutions. I have encountered candidates whose technical knowledge of a particular stack was somewhat rusty but who displayed an outstanding understanding of core concepts and problem- solving approaches.
One particularly memorable experience was a technical interview with a live coding session, where the candidate solved complex problems with such speed and precision that they outperformed more senior candidates. Their ability to break down problems, adapt quickly, and write efficient code left a lasting impression on me.
Fortunately, I have not encountered many negative interview experiences. In most cases where a candidate did not perform well, it was due to a gap in experience for the role, difficulty articulating their thoughts clearly in a required language, or an inability to fully showcase their potential under pressure. While these situations can be disappointing, I view them as opportunities for candidates to gain experience and improve for future interviews.
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?
Determining the quality of a candidate during an interview is a holistic process that takes multiple factors into account—communication skills, problem-solving ability, and theoretical knowledge. The importance of each factor depends on the level of the role and the candidate's background. However, if I were to prioritize them, problem-solving would come first, together with communication skills, while technical expertise would be secondary—except in cases where deep technical proficiency in a specific stack is a critical requirement for the role.
Qualities I value most in candidates are honesty and transparency. These traits lay the groundwork for strong team collaboration and help set the right expectations on both sides.
Lastly, I consider their previous work experience and the reasons behind any job transitions. I do not believe that job tenure alone is a key indicator of a candidate’s potential, as long as they can clearly articulate their reasons for moving between roles. I have encountered excellent professionals who have changed jobs frequently in a short period due to company culture, management challenges, or project-related issues—often where stakeholders were unwilling to address underlying problems or provide clarity. In such cases, understanding their perspective helps gauge how they approach workplace challenges and make career decisions.