About Us

30 Years of Experience

CSG was founded as Cornerstone Solutions Group in St. Louis, Missouri in 1989. For nearly 30 years, we have created custom software applications to help companies manage complex business processes that cannot be solved with off-the-shelf software. The state of the art solutions developed by CSG helps reduce cost, improve quality and assure growth.

State of the Art Technology

CSG helps your business improve its unique processes and realize market advantages from your data by creating software and data analytics solutions. Our software engineers design and develop new systems as well as updates or replacements for legacy systems. Our business intelligence consultants design and develop data warehouse solutions, create dashboards, and implement presentation and analysis tools that support decision-making.


Focused on YOU


Whenever CSG engages in a project, we evaluate many questions; questions about business processes, about data configurations, about testing environments and many, many more.

But there is one question we ask ourselves that is the single-most important question we can ever ask:

What’s the right thing to do for the client?

It’s not just about the technical application. It’s not about being correct. It‘s about a core principle that guides our interaction with you to hold your interests above our own. It’s about honor and integrity. And it is at the very core of everything we do at CSG.

When we opened for business in 1989, we set this simple precept as the guiding principle of CSG. It is a non-negotiable fact of life here.

We also believe it is why our customer retention rates are so high. We do what we say we are going to do—and our goal is to always do what’s right. We hire to that profile to ensure this aspect of our culture lives on.


Mark Peterman

President & CEO

Steve Lemmon

Vice President of Business Development

Will Bain

Vice President of Operations


Cornerstone is more than a company. We are a community that thrives on creating technology solutions. We develop lasting relationships with each other and our clients. We constantly refine our craft. We think it’s important to grow as people, consultants, teammates, and engineers. We achieve great things while keeping life in balance. And, we do all this by living out our core values every day.