Philippe Guerin
CTO North America - Head of Solutions Architecture at CAST
United States
About Philippe Guerin
Philippe Guerin is CTO North America - Head of Solutions Architecture at CAST. Location: United States.
CTO North America and Head of Solutions Architecture at CAST, based in New York. I have been with CAST since 2004, first in Paris, and in the United States since 2008. I lead the North American solution architecture team and work with cloud and system integrator partners on agentic software modernization. Most attempts to make AI reliable on large codebases work the same lever: give the model more context. I work the other side of the problem, making the context deterministic. Static analysis of a real application produces facts rather than probabilities about dependencies, data flow, transaction paths, and dead code. Delivered to an agent through the Model Context Protocol (MCP), those facts replace inference with lookup, which raises accuracy and reduces token consumption at the same time. Deterministic context is cheaper than large context and it is auditable. 25+ years architecting large-scale solutions, closing multi-million dollar deals, and serving as a trusted technical advisor to C-level and below at Fortune 25 to Fortune 2000 companies. A big picture thinker who translates complex business needs into technology strategy and tangible results. Core Areas of Expertise: Agentic AI and Deterministic Context: MCP servers that expose verified application structure to LLMs and autonomous agents. Grounding strategies that reduce hallucination and token cost on enterprise codebases. Assessing where an agent is reliable, where it is not, and what evidence closes the gap. Mainframe and Legacy Modernization: Leading and advising on large-scale modernization and transformation programs across COBOL, JCL, DB2, PL/SQL, and Java EE estates toward cloud-native targets, mitigating risk while maximizing business value. Joint modernization architectures with cloud and system integrator partners. Software Productivity and Measurement: Domain expert in risk-adjusted productivity measurement. Contributed to the CISQ/OMG standards for Automated Function Points (AFP) and Automated Enhancement Points (AEP) and led their productization. Executive Advisory and Solution Architecture: Guiding C-suite stakeholders on technology strategy, product management, and program management toward measurable business goals.
Skills
Additional experience
Head of Solution Engineering, Global solution Architect
CAST
June 2012 – January 2014
Education
- Strategic Communication, Columbia University
- Staffordshire University Certificate, University of Staffordshire