About Greymine
Experience that makes a difference. Our team has worked with 200+ sites worldwide and brings over 100 years of combined IT experience to every engagement.
Who We Are
Greymine is an IT consulting firm that specializes in legacy system modernization, EDI development, performance optimization, and AI-assisted development. We work with enterprise and mid-market organizations that depend on mission-critical systems built over decades.
We understand that these systems contain embedded business rules and undocumented institutional knowledge that can't be replaced by a simple code conversion. Our approach starts with understanding what your systems actually do — then reimagining how they should work.
AI augments our team's expertise. It doesn't replace the deep domain understanding that comes from decades of working inside complex enterprise environments. We use AI as a tool to accelerate the mechanical parts of modernization, so our engineers can focus on the decisions that require judgment and experience.
The Team
Gary Patterson
Gary brings over thirty years of hands-on IT experience across technical architecture, application development, project management, system operations, IT security, disaster recovery, and performance management.
His focus is on large, complex cross-platform applications — typically with an IBM midrange component (IBM i / iSeries / AS/400) connecting to other systems on Windows, AIX, Linux, and IBM mainframe.
Technical depth: CL, Java, ILE RPG, freeform RPG, REXX, Node.js, PHP, SQL, .NET, Cisco IOS/ASA/VPN/VOIP, WCAG accessibility, PCI/HIPAA compliance.
Michael Brock
Michael specializes in the modernization of applications — database, code, and UI — on IBM i on Power Systems. He also brings significant expertise in software optimization, database architecture, performance testing, and process improvement.
Michael has specialized in IBM midrange systems since the AS/400 launch in 1989. He participated in the launch of Hotels.com's iSeries and DB2-based website, later served as Director of Application Engineering at Expedia, and returned to consulting to focus on IBM midrange code modernization and optimization.
Technical depth: IBM i performance tools (iDoctor, Job Watcher, PEX, Collection Services, DB2 SQL Performance Monitor), all RPG versions, COBOL, DB2 SQL.
Doug Mewmaw
A 30+ year veteran in the IT industry, Doug has worked with hundreds of sites worldwide. He leads Greymine's performance management software practice and is the driving force behind PerfScan.
Doug recognized early that the industry needed a dedicated performance management tool that was modern, practical, and reasonably priced. PerfScan addresses capacity planning, historical analysis, and problem determination for IBM i environments.
Work with our team
Whether you need a full modernization engagement or targeted performance expertise, we're ready to help.
Get in Touch