Our Leadership and Experts

Managing Partner, Valuation & Strategy

László combines financial modeling with decision science, an applied discipline that unites analytics, statistics, and economics. With nearly two decades of experience advising energy, infrastructure, and resource-intensive companies, he brings a boardroom-caliber track record in navigating pricing, risk, and operational trade-offs. His approach is agile, data-driven, and rooted in real market signals, leveraging proprietary forecasting models and advanced stochastic methods.

As an independent advisor, László supports global consulting firms on complex analytical mandates, model validation, and audit-facing documentation. He is frequently appointed as a designated valuation expert, preparing regulator-ready materials and reviewing high-impact financial models.

His portfolio spans more than 20 global and regional clients, including leading utilities, infrastructure investors, and industrials across Europe and MENA. In addition to delivery, Laszlo leads executive briefings and capability-building programs that empower leadership teams and operational units to embed best-in-class practices in pricing, forecasting, and strategic reporting.

László also designs and delivers training programs, beginning with C-suite briefings and extending to hands-on coaching for operational teams. These programs are praised for clarity, relevance, and engagement. They are delivered across Europe and MENA and help embed consistent analytical standards within client organizations.

Managing Partner, Client Engagement

Ágnes brings over 20 years of professional experience, supported by a strong international academic background in international relations and cross‑border economic frameworks. Ágnes leads client engagements across the firm and is responsible for the structuring and execution of mandates, ensuring that advisory scope, delivery timelines, and resources are aligned with client objectives and executed to institutional standards. 

Ágnes oversees engagement delivery, coordinates project teams, leads proposal preparation, and serves as a primary point of contact for clients throughout the engagement lifecycle, ensuring disciplined execution, clear communication, and consistent, investment‑grade outcomes across all client assignments.

Partner, International Tax & Restructuring

Katharina is a highly accomplished tax advisor with deep expertise in international taxation, restructuring law, and financial accounting. She combines a strong academic background with extensive professional experience across multinational corporations, auditing, and advisory. Katharina provides strategic tax and financial guidance to companies and investors, helping them navigate complex regulatory environments, manage risk, and build resilient long-term business strategies.

With over two decades of experience across the Energy, Pharma, and IT sectors, Attila focuses on the strategic intersection of IT infrastructure, cybersecurity, and digital transformation. A PMP-certified leader, he brings deep expertise in managing complex cross-cultural projects, ranging from software platform development to Microsoft 365 integrations and the advancement of artificial intelligence and automation initiatives. Attila is adept at identifying innovative solutions to enhance system security and efficiency. He plays a vital role in streamlining operations and fostering a positive organizational culture, ensuring that technical strategies are both cost-effective and compliant with rigorous industry standards.

Partner, Energy Markets, Compliance & Risk

Kasper is a senior energy market advisor with over 30 years of board-level experience in global energy markets, energy trading, and the energy transition. He advises on energy transition projects, PPAs, regulatory compliance and market surveillance, and the trading and risk management of electricity, natural gas, and LNG. His expertise includes low-carbon hydrogen, BESS, CCUS, and global carbon trading and pricing across Europe, the Middle East, North America, and Asia.

Partner, Systems & Operational Strategy

With two decades of experience across engineering, finance, and corporate leadership, Balázs focuses on the intersection of business, systems, and technology. He advises clients on operational transformation, technical strategy, and complex system integration, combining deep analytical expertise with practical industry insight. He plays a key role in aligning Siller’s technical capabilities with client growth objectives, ensuring that business strategies are both operationally sound and technologically future-ready.

Senior Decision and Data Scientist

Martin holds a BSc in Physics and is pursuing an MSc in Applied Mathematics with a focus on Data Science at BUTE. He specializes in energy markets, with experience in short-term price forecasting and long-term power and commodity analysis. His research explores advanced analytical methods for energy market modeling, and he has supported several international consulting and energy projects. His research and project work reflect Siller’s commitment to applying advanced analytics to real-world energy and infrastructure challenges.

IT and AI Architect

Josef designs and builds scalable AI-enabled software systems across the full stack, from cloud-native architectures and secure APIs to data pipelines, business logic, and modern web frontends. He specializes in integrating AI services into enterprise environments, combining Microsoft Azure, .NET, modern Frontend frameworks, and MLOps-oriented patterns to deliver robust, maintainable, and production-grade solutions.

Contractor, Senior Data Engineering Lead, Energy & AI Platforms

With several years of experience in data engineering, focusing on designing and implementing industry standard data pipelines that support analytics and data science. Bence is recognized for his expertise in building scalable and reliable data engineering solutions that transform raw data into structured, analysis ready datasets. His work bridges engineering and business needs, enabling faster, data driven decision making and more efficient operations through robust, well designed data platforms.

AI Data Security Engineer

Security engineer with deep offensive security and penetration testing expertise, specializing in AI/LLM pentesting and generative testing to identify prompt-injection, data leakage, and agent/workflow vulnerabilities, then translating findings into practical hardening, guardrails, and secure-by-design controls for production AI.