Silicon Valley is known for its relentless pace, yet even here career leaps are typically measured in years. The story of Ukrainian engineer Serhii Klymenko is a rare career case: the combination of years of technical expertise and business thinking opens unexpected doors. A year ago he joined the American company Sift Science as a senior developer, and in less than a year he stepped into a leadership position — delivering results that significantly outpaced previous benchmarks. He shared his journey through five steps on the road to leadership.
Step 1. Value from Day One
Sift Science is an online fraud prevention company whose specialists ensure the seamless operation of payment systems for clients such as Twitter, DoorDash, Airbnb, and other giants in marketing, entertainment, and e-commerce. In August 2024, Serhii Klymenko joined its team and from day one demonstrated that he knew the company’s core products better than most of his colleagues.
“For two years prior, I had been a kind of ‘shadow architect’ of one of the company’s most critical products. I maintained the stability of Sift Console — a tool used by our clients’ analysts to monitor transactions and flag suspicious ones,” Serhii explains. “After two years of optimizing large-data rendering, fixing system bugs, and maintaining the codebase, I knew it as if I had written it myself.”
Serhii began contributing fully from his very first day: no adjustment period, no inevitable newcomer mistakes but clear ideas for improving both the product and team efficiency.
Step 2. Thinking in Product Terms
The difference between a junior and a senior specialist lies in the ability to tackle higher-complexity problems and propose new architectural solutions. The difference between a senior developer and a Staff Engineer lies in the ability to identify deep code-level issues and select the right developers to resolve them in the best possible way.
In March 2025, Serhii Klymenko proved to leadership that his expertise exceeded expectations — through a full overhaul of one of the most complex and convoluted products in the company’s portfolio. “The Dispute Management tool is what clients use when an end user has fallen victim to fraud and needs to recover stolen funds,” Serhii explains. “Its architecture was severely outdated and it ran slowly. I initiated a complete rebuild — without waiting for the tool to collapse under data pressure.”
Mr. Klymenko convinced leadership that maintaining the legacy Dispute Management codebase was slowing growth and putting partner trust at risk. Once he received the green light, he took full ownership of building an entirely new version of the product — one that was successfully tested and deployed in just a matter of months.
For the company, Serhii’s initiative became a testament to his exceptional abilities both as a developer and as a professional with leadership qualities. “When a developer simply closes tickets, the company sees them as an executor. Thinking in product terms opens new doors: opportunities for career growth and real impact on the company’s performance.”
Step 3. Clear Evidence of Effectiveness
Even the highest-quality work can go unnoticed without the right presentation. Technical results alone are not enough and brief reports in the format of “No bugs detected this month” don’t cut it either. Serhii regularly ran demo presentations for leadership, proving the value of his innovations through concrete numbers.
“I showed a direct connection between the new version of the application, the new useful features, and the time clients were spending resolving their own tasks. Refactoring — changing parts of the code without altering functionality — turned out to be a powerful business decision, and ultimately played a key role in my appointment as Staff Engineer,” he adds.
Step 4. Leadership as Part of Daily Work
The Staff Engineer role comes with accountability for the results of those you lead. Six other developers came under Serhii’s guidance, and in his role as mentor he also introduced innovative management solutions — chief among them a self-developed framework called Resonance Leadership. Under this approach, the manager steps away from the role of “supervisor” or controller and becomes a collaborative partner in solving problems alongside the developer.
“The methodology brings together a set of psychological tools that help developers grow professionally, independently find and address issues, and communicate effectively and without toxicity. After implementing this framework designed specifically for distributed teams with diverse cultural backgrounds Sift Science noticed that my team was closing tasks faster than colleagues in other departments. Delays disappeared and communication improved,” Serhii explains.
Step 5. Psychological Safety in Communication
When an Engineering Manager vacancy opened in June 2025, the company didn’t consider other candidates. Serhii — a person who combines deep technical expertise with outstanding leadership skills — was appointed immediately. Leadership had long observed a pattern: wherever Serhii’s innovations were introduced, uncertainty disappeared and employee engagement and motivation grew. His framework became embedded in Sift Science as a management standard.
“After implementing Mr. Klymenko’s leadership architecture, we noticed a growing interest from clients in our products, and engineer productivity increased by 30%. Without his contribution, the company would not have been able to achieve that level of cohesion and reach our improved performance benchmarks,” says Jintae Kim, Vice President of Engineering at the company.
Serhii himself notes that the nature of working and communicating in an American company requires fundamentally different approaches to team interaction. Western communication norms leave no room for directives, every idea must be justified. To build effective communication, he taught his team to give feedback and proposals through the principle of radical candor. Direct yet respectful feedback — not fixated on past mistakes but oriented toward the future — blends American respect with Ukrainian straightforwardness, enabling genuinely open communication.
Looking Ahead
Serhii Klymenko is actively working on expanding the methodology: presenting it to other departments at Sift Science and developing a methodological map of the framework. “I want to make an ‘adapted Ukrainian approach’ synonymous with efficiency and humanity in the Valley. Engineering management needs to evolve, and my framework has already demonstrated that it can give other managers the tools for more reliable leadership,” Serhii comments.
His rapid success at the company came down to his mindset: working like a business owner, not an employee. It’s what it means to make the most of your opportunity at a company — to exceed expectations, develop leadership qualities, and prove effectiveness through innovative solutions.
