Marko has been a partner of Clayton Utz since 1999 and heads the firm's Commonwealth infrastructure practice. Marko specialises in all aspects of infrastructure, including design, construction, financing, operation, maintenance, remediation and disposal. One of Marko's long-term clients (for over 20 years) has been the Department of Defence. In this role Marko has developed delivery models for both the design and construction as well as the operation and maintenance of defence infrastructure. Most recently, this has involved a focus on integrated project delivery, which is designed to maximise the sustainability of infrastructure and other whole of life outcomes. Marko is well-known throughout industry, as he speaks and publishes widely on infrastructure related issues.