Machteld is a partner in our Litigation practice and heads its Mass Claims & Class Actions group. She acts for national and international companies in complex domestic and cross-border litigation and has extensive experience at all levels of the Dutch judiciary, including the Supreme Court. She frequently publishes and lectures on collective redress and civil procedure, and is a co-author and co-editor of Unlocking the WAMCA. She is also the chair of the editorial board of the Mass Claims law journal and a founding board member of the Dutch Association for Mass Damages and Collective Action (VEMCA).

Machteld has been ranked as a leading partner in Legal500's Dutch Class Actions rankings for several years and was inducted into the Hall of Fame in 2026. Clients have praised her highly, with one describing her as an "excellent strategist" offering "creative solutions" and "always ready to challenge the status quo", and another writing, "Machteld de Monchy is tremendous: intellectually first class, pragmatic and commercial, and great fun to work with" (Legal500, 2026). She is also recognised in Chambers in the general litigation category.

Machteld leads De Brauw's Pro Bono practice and has received several awards in recognition of her efforts and the firm's pro bono work, including the Pro Bono Publico Award from The Legal Aid Society (New York) following her one-year secondment to Paul, Weiss.

Machteld's recent work includes representing

• DAF Trucks as global lead counsel in many follow-on damages proceedings following the European Commission's decision to impose EUR 3 billion fines on European truck manufacturers
• Booking.com in a damages class action and group proceedings alleging infringements of competition and consumer law
• Amazon in a GDPR damages class action, including a referral to the European Court of Justice
• Philips in a matter relating to allegedly defective medical devices
• Women's rights organisation Bureau Clara Wichmann in a matter relating to the treatment female prisoners