TwentyOne Solutions

Senior technical operators, not order takers.

We are a small team of developers, product thinkers, and entrepreneurs who have built and scaled mission-critical systems.

Sergei Golimbievsky
Founder

Sergei Golimbievsky

A 30-year software veteran, Sergei is a technical powerhouse who excels at turning complex business challenges into cutting-edge AI and software solutions.‐

Seth Lewandowski
Partner

Seth Lewandowski

A business-minded software expert, Seth has launched 20+ full-stack products and specializes in building high-impact, scalable software that drives real-world success.

Seth Black
Senior Product Engineer

Seth Black

Seth is an experienced software developer specializing in modern web applications. With a strong background in client-facing roles and customer success, he brings both technical depth and a user-first mindset to every project.

Alisa Chavez
Software Developer I

Alisa Chavez

With an extensive medical background and growing technical expertise, Alisa bridges healthcare and technology to create intelligent, user-centered solutions for care-centered clients.

Our Philosophy

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Judgment over volume

We focus on solving the right problems, not just writing more code. Our value lies in knowing what to build and, more importantly, what not to build.

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Business-first leadership

Technology is a tool for business outcomes. We approach every technical decision with a deep understanding of your commercial objectives and market position.

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Long-term trust

We operate as your long-term partners. Our engagements are built on transparency, accountability, and the shared goal of building sustainable technical equity.