About · eFellows

Stacked expertise.
Compounding experience.

We started with infrastructure in 2004, and we never stopped operating it. Cybersecurity joined in 2006, protecting what we build and run. Platform engineering arrived in 2018 and grew into our flagship as its practices spread through everything we do: infrastructure as code, GitOps, automation by design. In 2025 we saw where the industry was going and moved fast: we embraced AI, shifted our main focus to applying it across everything we do, and opened two new areas of expertise at once, agentic engineering and the AI/ML platforms it runs on.

Every discipline we ever adopted still runs today. Each new one was learned while the previous ones kept running at full SLA, and none of the four has ever been retired.

Built for this era, twenty years early.

The AI era made execution cheap and judgment expensive. What is suddenly scarce is critical thinking, calibrated skepticism, ownership under ambiguity, and the discipline to verify rather than trust. That is, almost line for line, the character we have hired and built around since 2004. We did not scramble to adapt to a world that changed under us. The world just started paying a premium for who we already are.

Part product company. Part systems integrator.
Part lab. Run by engineers.

We are an engineering company that runs today as part product company, part systems integrator, part lab. The products are the platforms we build and sell. The integration work is everything we design, build, and operate for clients. The lab is where both are tested on our own operation first. Fifty engineers in a company of sixty.

Founders-led. Engineers-run.

eFellows has been led by its founders since inception. When the CEO chair changed hands in early 2026, it passed from one co-founder to the other. No outside management, no private-equity playbook, no pivot by committee: the people who started the company are the people running it. The structure is lean and flat: nothing sits between a decision and its delivery.

Rostislav Rusev

CEO

Borislav Lazarov

CTO

Ivan Pavlov

Wise wanderer

The engineering core. Most of the engineering leadership has been with the company for ten to fifteen years or more. That core is what drives eFellows forward: curious minds and hardcore experts who surround themselves with other high achievers, and the reason the company grows organically in expertise rather than by acquisition.

The engineering approach

Broad expertise, built on fundamentals

We invest in knowing how things actually work, across the whole stack. Well-architected solutions come from breadth plus depth, and there is not a shortcut.

First principles, every time.

We do not follow trends, we understand the foundations underneath them. Every decision and every design rests on reasoning we can show you. That is why the design still holds five years later.

Vendor, product, and medium agnostic

Client needs first. We are not a vendor's external sales team.

Parity between on-premises and cloud.

Genuine equal strength in both, which is what complex hybrid projects, migrations, and deep troubleshooting actually require. Most firms have one and claim the other.

Enforced formalism in infrastructure.

Infrastructure configuration becomes company IP. Processes document themselves. Teamwork scales. We get there through multi-layer abstraction frameworks like CAF, infrastructure as code, and automation by design, always in the context of the SDLC.

Expertise

Well-architected is what is left when the thinking underneath was hard enough. Below is that thinking: what we optimize for, how we get there, and what you own at the end.

Self-service and self-reliance

People take control of their own tasks. External dependencies get designed out, not managed.

Fewer dependencies between people and teams.

Silos get broken down; communication and process get shortened. A team that has to wait on three others is not a team, it is a queue.

No idle blocked time.

Work keeps flowing. Roadblocks get addressed the moment they appear, and planning is done to prevent them in the first place.

No waiting.

Builds and tests are optimized to be fast and automated to be reliable. Engineer time spent watching a progress bar is engineer time wasted.

How we deliver

Projects

Built to last. Delivered complete. Architecture, deployment, configuration, hardening, migration, knowledge transfer. Combined teams from day one.

Operations & Support

Operated as if it's ours. We help organizations run their critical systems. Under SLA, whatever the complexity and whatever the hour.

You own what we build

Knowledge transfer is in every engagement, both shapes, and it is not a workshop bolted on at the end. It is documented processes, joint operations, shared troubleshooting, and progressive handover throughout. We have no interest in artificial lock-in. When the engagement ends, your team runs the platform independently, with full ownership of the codebase and the know-how. A client who cannot operate what we built is a project we did badly.

Certified since 2006

The formalism is not only cultural. Our quality, security, service management, environmental, and privacy systems are independently certified, and audited every year since 2006.

Trust Center