Siller is a business and management consulting firm based in Austria, serving Europe, the Middle East, and Asia. We are recognized for providing independent, objective valuations of companies and projects that give leaders the clarity and conviction to act decisively.
As a boutique advisory firm, we work selectively with senior executives who face their most complex decisions. Our approach combines Decision Science with decades of executive insight, ensuring clarity, precision, and lasting impact. Each engagement is fully tailored, since at this level no two decisions are ever the same.
Our strength lies in our ability to operate effectively in both contexts: as an independent, highly focused advisor to CEOs and boards, and as a trusted partner within large-scale, multi-advisory initiatives. We bring the discretion, agility, and personalization of a boutique firm, while also possessing the experience to integrate seamlessly into global, structured environments.
This unique capability allows us to deliver value wherever top leaders need us most, from individual executive counsel to complex projects involving multiple stakeholders.
Years in Business
Founded in Austria, building trusted partnerships since 2015.
Years of Combined Experience
Our advisors unite decades of know-how across industries and geographies.
Organizations in 11+ Countries
Serving clients across Europe, the Middle East, and Asia.












Over the past ten years, Siller Decision Science has grown from a local advisory firm in Austria into an independent partner supporting clients in strategic, financial, and operational decisions.
At Siller Decision Science, we welcome conversations with leaders who are shaping tomorrow’s decisions. Please share your details, and our team will reach out to you within 3–5 businesses days. We look forward to connecting.
🌐 Language: English | Deutsch | Magyar
Siller — Established 2015 Austria
Company Name: Siller Handels GmbH
Address: Gemeindeweg 47, 3422 Altenberg, Austria
Company Register Number: FN 442495 d
VAT Number: ATU69992868
Siller is the consulting brand of Siller GmbH.
Siller GmbH is a limited liability company under Austrian law. The information provided on this website is for general informational purposes only and does not constitute professional advice. Siller GmbH accepts no liability for any actions taken based on this information.
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Clarity. Direction. Results.
Independent perspectives on markets, transformation, and the systems shaping economies