Before establishing SMM Advocates, Wincen was associated with the renowned international law firms O’Melveny & Myers and DLA Piper, where he handled a diverse array of legal matters. His expertise covered areas such as bankruptcy and restructuring, competition, commercial disputes, cross-border acquisitions, employment, general corporate issues, international arbitration, and investigations. Notably, he was seconded to Pfizer Indonesia, where he managed all the company’s legal affairs.

As a Partner at SMM Advocates, Wincen has advised major multinational companies on conducting business in Indonesia and leading significant acquisition transactions. He has also led the firm’s dispute resolution practice. At SMM Advocates, he has worked with a distinguished clientele, including leading FTSE 100 and S&P 500 companies.

Currently, Wincen serves as a Vice-Chairman of the Continuing Education Division of the Indonesian Advocates Association and a delegate to the International Chamber of Commerce Commission on Arbitration.

He has been invited as a speaker and expert by numerous key stakeholders, including the Indonesian Competition Commission, the Indonesian Ministry of Defence, and various Indonesian state-owned enterprises. Additionally, he has facilitated and spoken at prominent forums such as the International Chamber of Commerce, the Singapore International Arbitration Centre, the Indonesian Advocates Association, and the Law Society of Singapore. His writings have also been featured in leading publications, including the International Financial Law Review and Lexis Nexis Advanced for Bankruptcy Law, Competition Law, and Arbitration.  In his spare time, he practices Aikido and Muay Thai.

The Chambers Asia-Pacific 2025 noted, “Wincen Santoso has a very strong commercial vision. He is a seasoned, versatile, and insightful lawyer.”

The Legal 500 Asia Pacific 2025 described “Wincen Santoso is compared to by clients as a chess grandmaster.”