Who is Jefferson Rafael Kozerski?

I'm Jeff: a software architect, CTO, and entrepreneur with over 19 years building products, operations, and technology teams.

My journey started early, back in the dial-up internet era, with tech courses, computer maintenance, curiosity, and long nights of self-directed learning. Soon after came the first projects, the security world, and the founding of my first company.

Later I founded Extraball, which was acquired by Infracommerce. From there, I moved into increasingly complex operations until reaching Principal Engineer and C-level roles, accountable for architecture, performance, scale, and business outcomes.

Today I bring a perspective that combines technical depth with executive context. I believe technology decisions only make sense when they fit the company's moment, the available team, and the real business impact.

In recent years, that background in web architecture and high-scale operations has expanded into artificial intelligence. I use AI to increase capacity, accelerate delivery, and design smarter workflows for companies and professionals.

This page is not meant to summarize an entire career. It exists to show the person behind the work and the principles that guide how I build, lead, and decide.

Me, beyond tech

Technology takes up a big part of my day, but it does not define all of who I am. A few things that shape me off-screen:

Music — Drummer since my teenage years. Music taught me discipline, timing, and the importance of listening before playing. That carries into technical leadership and into how I create.

Sport Shooting — Sport shooting practitioner. It is a sport that demands focus, control, and precision under pressure, which maps closely to decision-making.

Family — Present father. Parenthood changed how I think about priorities, time, and responsibility, both inside and outside work.

Homelab — I have a home lab where I test, break, and rebuild infrastructure out of pure curiosity. What I learn tinkering ends up becoming real-world solutions in my day-to-day work.

Health — Advocate for ergonomics and mental health in and out of the workplace. I work out, take care of my body, and believe that real high performance starts with the person behind the screen.

Principles

Performance is a business feature

Every millisecond impacts revenue. I treat performance as a financial metric, not a technical one.

The best architecture survives the next Black Friday

I design for the worst-case scenario, not for the PowerPoint. Systems that scale when it matters most.

I learn by building

Everything I recommend, I've already built and shipped to production. My foundation is real-world experience.

Trade-offs, not buzzwords

Every technical decision has a cost. My job is to make those costs visible to the people who decide.

Ownership

I treat every project as if it were my own. To me, ownership shows up in how people decide, respond, and carry the work through.

Context before solution

The best technical decision depends on the business moment, the team's maturity, and real constraints. Good architecture is the one that fits the current context and stays healthy as that context changes.

"When it comes to commitment, effort, and dedication, there is no half measure. You either do something well or you don't do it at all."

— Ayrton Senna