Whitehorn Ltd. Co. is a legacy system modernization firm serving government and enterprise organizations. We don't do general IT consulting. We do one thing: analyze, document, and modernize the aging systems that your operations depend on - the codebases that keep running but haven't been touched in decades, built by people who have long since moved on.
Whitehorn Ltd. Co. also owns and maintains DR DOS®, a DOS-compatible operating system dating back to 1988 - giving us source-level access to the kind of legacy platform most firms can only consult around.
Jason Whitehorn
Jason has spent decades leading engineering teams inside the kinds of organizations that Whitehorn Ltd. Co. serves - and inheriting the kinds of systems that Whitehorn Ltd. Co. modernizes. He's been the CTO brought in to untangle legacy architectures, the director scaling engineering organizations through rapid growth, and the hands-on architect working inside SCADA systems, billion-row timeseries databases, and the codebases that everyone else avoids.
His career spans energy, financial services, retail, and technology - from building real-time oil and gas monitoring systems and AI-driven equipment health platforms to leading full application rewrites delivered incrementally without a single day of downtime. He's been on both sides of the table: the executive making the modernization case to the board, and the engineer doing the work.
How We Work
Principal-led, scaled to fit
Whitehorn Ltd. Co. is a principal-led firm. Jason leads every engagement directly - you get the founder, not a junior associate learning on your project. When an engagement requires additional capacity, we assemble specialized teams with domain expertise matched to the work, drawing on trusted engineers and subject matter experts we've vetted and worked with across our careers.
This model exists for a reason. Decades of building and scaling engineering organizations means we know how to staff, manage, and deliver. The difference is that every engagement has senior leadership at the table from day one through delivery, with the flexibility to scale up or down as the work demands.
Why We're Different
Not just what we know - what we own and what we've done
We Own a Legacy OS
Owning and maintaining DR DOS gives us source-level access to legacy platforms - capabilities no consulting engagement can replicate.
We've Been in Your Chair
Our founder has been the CTO inheriting legacy systems, making the case for modernization, and delivering it - multiple times, across multiple industries.
We Build, Not Just Advise
We write code, migrate data, and ship working systems. We don't hand you a strategy deck and wish you luck.
We're Honest About Fit
If lift-and-shift is enough, we'll say so. If the system needs a full rebuild, we'll say that too. Our assessment is designed to find the right answer, not the most expensive one.
Partner Programs
Credentialed by the platforms we work with most
The technology companies your organization already trusts have recognized us as partners. As a Microsoft AI Cloud Partner and an IBM Partner Plus member, we deeply understand what keeps your business running.
Microsoft AI Cloud Partner · IBM Partner Plus
Principal-led modernization for systems you can't afford to get wrong.
Work With Us