CMS has advised Callstack.io, a global leader in React Native and cross-platform application development, on its acquisition of Margelo GmbH, a Vienna-based software engineering consultancy renowned for its high-performance mobile technologies and contributions to the React Native open-source ecosystem.
The transaction, which values Margelo at more than EUR 20 million, represents Callstack’s first acquisition since receiving a growth investment from Viking Global Investors in 2025. The acquisition is a key milestone in Callstack’s strategy to expand its technology offering, strengthen its open-source capabilities and support its continued international growth.
The combination brings together Callstack’s extensive enterprise delivery experience with Margelo’s deep technical expertise and globally recognised open-source technologies. Margelo is best known for developing widely adopted solutions including Nitro Modules, VisionCamera and react-native-mmkv, which are used by developers and companies worldwide.
Alexander Rakosi, Partner in Corporate/M&A at CMS Austria and lead partner of the international CMS team comments: “We are pleased to have advised Callstack on this transaction and an important strategic step in the company’s growth journey. By bringing together two highly respected innovators in the React Native ecosystem, the transaction creates a compelling platform for further technological development and international expansion. We would like to thank the Callstack team for their trust and excellent collaboration throughout the process.”
The cross-border CMS team advising Callstack was led by Alexander Rakosi and Daniel Grimmer (CMS Austria), together with Sławomir Czerwiński and Grzegorz Pączek (CMS Poland).
Core Team CMS Austria:
Alexander Rakosi, Lead Partner | Corporate/M&A
Daniel Grimmer, Attorney-at-Law | Corporate/M&A
Rebecca Herlitz, Associate | Corporate/M&A
Team CMS Austria:
Yara Al-Harbi, Associate | Corporate/M&A
Wolfgang Hellsberg, Partner | Banking & Finance
Mariella Kapoun-Reiter, Partner | Real Estate & Construction
Daniela Krömer, Partner | Employment
Andreas Lichtenberger, Laywer | Commercial
Hans Lederer, Partner | Intellectual Property
Clara Puczynski, Associate | Real Estate & Construction
Isabella Redl, Attorney-at-Law | Intellectual Property
Kai Ruckelshausen, Partner | Banking & Finance
Alexander Sommergruber, Associate | Antitrust, Competition & Trade
Dieter Zandler, Partner | Antitrust, Competition & Trade
Team CMS Poland:
Sławomir Czerwiński, Partner | Corporate/M&A
Grzegorz Pączek, Counsel | Corporate/M&A
Dominika Cichorek, Associate | Corporate/M&A
Tomasz Gwiazdowski, Corporate/M&A
Piotr Podsiadły, Associate | Emplyoment
Michał Tutaj, Associate | Emplyoment
