When someone stays with a company for a full decade, it speaks volumes about their dedication, the culture they’ve helped shape, and the value they continue to bring. We’re proud to celebrate Kosta Terziski’s 10-year anniversary at Cosmic Development this year.
From his early days in manual testing to leading QA efforts on a long-term client project, Kosta’s journey has been shaped by consistency, curiosity, and quiet impact. A few years ago, we shared a glimpse of that path in an earlier interview, where he reflected on his transition from beginner to pro. Now, with a full decade behind him, we checked in again, this time with a wider lens, to hear what he’s learned and what it’s meant to grow with Cosmic.
10 Years in Tech: Lessons in Growth and Resilience
One of the biggest lessons I’ve learned is that growth doesn’t come from chasing every new tool or trend. The tech world moves fast, and it can be easy to feel like you’re constantly catching up. But over time, I’ve found that staying consistent, being curious, and building strong fundamentals make the biggest difference.
I’ve grown through challenges, working with tight deadlines, adapting to shifting team dynamics, and stepping into situations that pushed me out of my comfort zone. That’s where I learned the value of resilience and patience. I also stopped hesitating to ask questions, even if they felt too simple at first.
From a professional perspective, I’ve come to appreciate how important communication and collaboration are in QA. It’s not just about running tests; it’s about helping the entire team build better software. That mindset shift has been key for me, and I try to pass it on to the people I work with.
From Final Step to Strategic Role: The Evolution of QA
When I started, QA was usually treated as the final step in the development cycle. Testers were expected to come in at the end and check if everything worked. Manual testing was the standard, and automation was more of a bonus than a requirement.
Today, the role is a lot more integrated and technical. QA is now involved from the start — from reviewing designs and thinking like end users to contributing to CI/CD pipelines, building automation frameworks, and working with APIs and infrastructure. Testers are no longer on the sidelines. We’re part of the process, helping shape how the product is built.
To stay current, I focused on continuous learning and got comfortable using tools like Cypress, TypeScript, and various API testing frameworks. I took on challenging automation tasks and explored approaches like shift-left testing and test strategy design. Also, I made a point to stay close to development — pairing with engineers, keeping up with code changes, and improving how I write and maintain test suites.
But more than any single tool, what helped me grow was staying open to change. That included unlearning old habits and being okay with not having all the answers right away. That mindset has made it easier to evolve with the role and contribute to how QA is valued on the teams I’ve worked with.
Staying Connected to Company Culture While Working Solo
For the past five years, I’ve been the only Cosmic team member working full-time on a long-term client project. I’ve been completely embedded in their team — attending daily standups, working side-by-side with their developers, and contributing to their product like any other team member. But even with that deep integration, I’ve always carried Cosmic’s values with me.
The mindset that helped most is seeing myself not just as a contributor, but as an ambassador. I represent the company in every interaction, so I bring our standards of professionalism, collaboration, and quality into the work I do. That means showing up consistently, building good relationships, and delivering results that reflect well on Cosmic.
I also stay in regular contact with the team at Cosmic. I check in with leadership, stay updated on what’s going on internally, and share insights from my experience whenever it can help others. Even though I’m not in the office, I’ve always felt like part of the team.
At the end of the day, I think it comes down to a sense of ownership. I care about the project, but I also care about representing Cosmic the right way. That’s helped me stay aligned, even when working independently.
Building QA from the Ground Up: A Project to Be Proud Of
One project I’m especially proud of is building the QA automation process for a long-term client project — completely from scratch. When I joined, no structured QA process or automation was in place. I had to start by analyzing the product, understanding the workflows, and then gradually designing and implementing a scalable test automation framework using Cypress and TypeScript.
As the only QA engineer and the only Cosmic team member on the project, it was definitely a challenge. I had to balance the technical side of the work with building trust and setting clear expectations with the development team and stakeholders. I became essential to the release process by contributing test coverage, providing early feedback on new features, and helping with risk analysis and quality planning.
What made it especially rewarding was seeing the results. Release cycles became faster, production bugs dropped, and the team’s mindset toward quality shifted. Being able to drive that kind of change, while also representing Cosmic in a visible and impactful way, made it one of the highlights of my career.
Three Words That Define a Decade at Cosmic
Growth. Trust. Impact.
Growth, because over the years, I’ve gone from manual testing to building full automation frameworks and from being a team contributor to someone who can work independently and lead quality efforts.
Trust, because being given the responsibility to manage a long-term client project on my own showed that the company had real confidence in me. That trust has pushed me to take ownership and give my best every day.
Impact, because I’ve seen the results of my work — whether it’s smoother releases, better test coverage, or helping shift how teams approach quality. Knowing I’ve made a difference for both the client and Cosmic is something I’m proud of.
A Decade Behind, a Future Ahead
Kosta’s journey shows what’s possible when technical skill is paired with trust, discipline, and long-term vision. In a world that moves fast, he’s been a steady, reliable force — both for our clients and for our team.If stories like this resonate with you, or if you’re curious about the people and projects that shape our culture, feel free to visit our page to learn more about who we are and how we work.