How to Build Scalable Systems and Stay Effective: Practices of a Senior Engineer
In the era of digital transformation, system resilience has become a strategic asset for companies. Behind the polished interface of any mobile application lies a complex architecture capable of handling millions of operations and meeting regulatory requirements.
Ilia Titovskii — an engineer with international experience and 15 years in the field — specializes in building scalable backend platforms. We spoke with him about architecture principles, professional growth, and how a senior developer can remain effective in a fast-changing industry.
Ilia, what does “scalable system” mean to you?
— Scalability is the ability of a system to grow without having to be rewritten from scratch every six months. It’s not just about handling multiplied load, but also structural flexibility. A proper architecture allows entering new markets, implementing new use cases, and integrating systems without an “architectural crisis.” The main indicator here is predictability: the system should evolve organically, not at the cost of heroic efforts from the development team.
Which principles do you consider fundamental when designing architecture?
— The first is modularity. Every component should perform a single function and have clear boundaries of responsibility. The second is observability. Logs, metrics, alerts — without these, you cannot manage the system. And the third is predictable behavior. If the architecture is clear, it’s easier to maintain and evolve, especially as the team grows and changes.
How does the role of a senior engineer differ from a mid-level engineer?
— While a mid-level engineer focuses on solving the immediate problem at hand, a senior thinks about what that solution will become in a year. At this level, you stop just writing code and start managing risks. Every architectural decision is always a trade-off between delivery speed and future maintenance costs. A senior engineer knows how to find this balance and, more importantly, serves as a “bridge” between business and technology. They translate abstract business goals into system requirements, clearly explaining where we can accelerate and where technical constraints dictate the rules.
How do you stay professionally relevant in a rapidly evolving industry?
— In our industry, learning is a natural process — like breathing. But for a senior engineer, it’s more important not just to accumulate knowledge endlessly, but to develop experience-based intuition. The key isn’t knowing everything — that’s impossible — but understanding why a particular technology is needed.
I am convinced that reading articles gives less than 10% of the experience you gain by developing your own product. The best way to truly “feel” a technology is to bring it into a pet project. When you build a system end-to-end yourself, you don’t just see marketing promises — you encounter the real pitfalls you’ll face in implementation. This is how engineering intuition is formed.
What is the main challenge for engineers today?
— The main challenge is the transformation of the developer role itself. We are entering an era where code writing is increasingly delegated to AI. Today, “just coding” is no longer enough. The ability to take full-cycle responsibility — from deep business requirements analysis to testing strategy and ongoing support — comes to the forefront. An engineer becomes an architect of meaning, understanding how technical decisions affect company profits and losses.
You have been recognized with professional awards, including the Nova Awards and the Global 1000 Award. Can these be seen as confirmation of your expert position in the industry?
— I see them as a sign of trust from the professional community. Such awards usually involve independent evaluation, which is important, especially in an international context. But more important to me is this: participating in such initiatives means being part of a professional dialogue. You’re not just working inside your company; you’re part of a broader technological ecosystem. This experience disciplines you. When you are invited to evaluate others or recognized for your achievements, it raises your internal standards, making you even more attentive to the quality of your own solutions.
If you had to summarize your professional principle in one sentence?
— Build systems not for “today,” but for growth. The right architecture is one that not only supports the current scale but allows the system to evolve alongside the business without losing resilience.
