Our People
Our team is built to perform.
Our success stems from our people — expert engineers, project managers, and drafting professionals who share a passion for precision and process.
We don’t just build machinery — we collaborate, test, and innovate to deliver bespoke solutions that solve complex problems. Precision is our obsession.
We’re the people behind the machines.
Carey O’Keefe
Founder and Principal
In 2005, Carey founded Lime Systems, driven by a vision to create a truly customer-first business. Since then, he has led the company through some of Australia’s most complex engineering projects, including the delivery of one of the country’s largest flocculant plants at Iluka’s Jacinth Ambrosia site.
Renowned for his sector knowledge, relentless energy, and commitment to quality, Carey continues to inspire the team with a clear and enduring philosophy:
“Design and build every piece of equipment better than the last—because better never rests.”
Clint Turner
Head of Drafting
Clint Turner, the Head of Drafting, joined Lime Systems in 2009 as a Draftsman/Project Manager, utilising his management skills gained from previous roles outside the industry.
His proficiency in transforming designs from the screen to high-quality equipment led to his promotion to the Head of Drafting in 2011.
Clint’s leadership guides a team of five skilled draftsmen and is integral to Lime Systems’ leadership team.
Notably, he considers the design and construction of the complex Lime Slaker at the Lihir Gold plant in Papua New Guinea as an exceptional example of turning design concepts into reality.
Branko Matic
Estimator
Branko Matic, the Estimator, leads the Estimating function at Lime Systems.
Branko brings extensive expertise to his position with over 21 years of experience in various engineering roles at companies such as Schlumberger, Halliburton, Yokogawa, and SCEE.
In addition, he holds a Bachelor of Technology Degree in Instrumentation and Control Engineering, an Advanced Diploma of Engineering in Instrument and Control, and a Postgraduate Certificate in Project Management.
Branko thrives on creating value for Lime Systems’ clients by developing tenders that leverage the company’s engineering and problem-solving capabilities to meet their needs and overcome challenges.
James Slack
Chief Executive Officer
James Slack is an accomplished CEO with a global perspective and a strong track record of leading high-growth organisations through transformation and scale. With leadership experience spanning Asia, North America, Europe, and Australia, James brings a sharp strategic lens to every challenge—whether driving digital innovation, expanding into new markets, or enhancing operational performance.
Known for his entrepreneurial mindset, James is passionate about building inclusive, high-performing teams and fostering a culture of trust, collaboration, and excellence. His expertise covers corporate strategy, governance, and financial leadership, and he consistently focuses on working with clients to deliver long-term, sustainable growth.
A forward-thinking leader in the mining sector, James excels in navigating complexity and creating value in even the most challenging environments.
Jascha Marwitz
Chief Operations Officer
Jascha Marwitz is a key force behind Lime Systems’ continued growth and operational excellence. Since joining the company seven years ago, he has advanced through roles in Tendering, Engineering, and Projects before stepping into his current role as COO.
Jascha brings both technical depth and strategic insight with a Bachelor of Mechanical Engineering (Hons) and an MBA from UWA. He has played a central role in major projects, including the Gruyere Gold Project’s Flocculant Plant design, supply, and commissioning in 2018.
Known for his collaborative leadership style, Jascha is passionate about guiding teams to solve complex challenges and deliver results together.
Luke Fisher
Finance & Personnel Manager
Luke Fisher, the Finance & Personnel Manager, has been with Lime Systems for nearly a decade, fulfilling various roles, including drafting and selling spares and accessories.
As the current Finance Manager, Luke oversees the day-to-day financial management of the organisation.
However, he goes beyond numbers and is deeply committed to areas such as Human Resources, Occupational Health & Safety (OH&S), and Environmental, Social, and Governance (ESG) practices.
In addition, Luke focuses on providing the necessary people capability and skills development to foster a safe and motivated work environment where Lime Systems can deliver exceptional client results and build enduring relationships.