The success of any startup depends on the strength of its team from the very beginning. Skilled engineers set the right pace, build the company’s internal culture, and create the first working prototype — the foundation that often determines the project’s future.
Mariia Kozak, Senior Engineer and Startup Fund Expert, knows this firsthand. When the New York-based startup Level All was just getting off the ground, she was among the first to join the team and helped build the company’s engineering core almost from scratch. Mariia personally took part in the hiring process and believes that a strong engineering team provides the solid ground every growing product needs. In this article, she shares her view on how to build such teams.
Start Small but Think Systemically
Modern startups are tending toward small teams. In 2022, for example, the average tech startup team at the seed funding stage consisted of up to 6 people, but within two years, this number had shrunk to 3. While companies are certainly trying to cut budgets, they've also come to the realization that quality is always more important than quantity. Mariia Kozak advises founders to approach hiring, especially for engineering positions, with particular care, as early hires become the foundation for the product's long-term development.
Mariia joined Level All at a stage when the company didn’t yet have a real product team — everything was still handled by external vendors. She was one of the first engineers on the team, and her strong technical background earned her the trust to participate in building the team. Mariia conducted QA interviews, spoke with candidates during hiring rounds, and later helped new engineers integrate smoothly into the team’s workflow.
“In early-stage startups, the first team always wears many hats — you’re building the product while also building the team itself,” says Mariia. “You develop trust, communicate across departments, and help each other find new people who fit the culture and can grow with the team.” She believes this is where the qualitative approach matters most. It’s better, she says, to spend more time carefully selecting engineers than to hire several people at once and then invest even more time and resources in their onboarding.
Hiring Beyond Skills: Looking for Ownership and Communication
During QA interviews and general hiring rounds, Mariia Kozak always paid close attention to a few key qualities in candidates — curiosity, accountability, and communication skills. “Technical skills are very important, but if there are small gaps, they can always be filled,” Mariia says. “But if a person can’t communicate or doesn’t want to be a team player, that can destroy a team very quickly.” Sometimes, even strong engineers had to be let go because of that.
In interviews, Mariia looked at how candidates reasoned, asked questions, and explained their decisions. Curiosity and an inquisitive mindset, she says, reveal how an engineer will approach problem-solving and teamwork. Such qualities are vital in a startup’s early stage, when the team needs people who are not just skilled but truly invested in the product’s mission.
Thanks to Mariia’s approach, which balanced technical proficiency with strong personal qualities, Level All built an effective, cohesive team. “By the time I left the company, we already had a Head of Engineering, Product Manager, Product Designer, and a full group of engineers,” Mariia recalls. “I’m proud that I was part of that journey, seeing how a strong team can grow almost from scratch.”
Building Processes Without Killing Agility
At the early stage, it’s also important to maintain a balance between flexibility in decision-making and a structured approach. Processes shouldn’t be chaotic, but excessive rigidity and constant layers of approval won’t bring efficiency or create a foundation for growth, says Mariia Kozak.
Based on her experience at Level All, Mariia recommends building structure collaboratively with the team. They regularly held code reviews, short syncs to share ideas, and followed CI/CD principles to keep updates moving quickly.
In interviews, she asked candidates how structured their past teams were, how they aligned with business goals, and whether they were proactive about improvements. For Mariia, mental flexibility and structure aren’t about bureaucracy — they’re what keep a startup steady when challenges arise.
Conclusion: Growing Engineers, Not Just Teams
Strong teams don’t build themselves, and assembling them takes more than experienced HR professionals. Founders and key members of engineering teams should take part in hiring people who not only value clean code but also keep the product’s long-term goals in focus. Curiosity, openness to dialogue, and flexibility in decision-making shape what a startup team will become. These are the qualities Mariia Kozak advises founders to look for if they want to enter the market with a truly strong team behind them.
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This article was published Nov. 28, 2025.
