Software Engineering Institute | Carnegie Mellon University
Software Engineering Institute | Carnegie Mellon University

Staff Profile

John Klein

John Klein

Senior Member of Technical Staff

Key Responsibilities

John Klein consults with commercial and government organizations to develop and evolve architectures that satisfy business and mission goals. Through these consulting engagements, John identifies common challenges, and then conducts research to develop practical and repeatable solutions across the entire architecture lifecycle.

Areas of expertise: software architecture, enterprise architecture, systems of systems, ultra-large-scale systems, big data, distributed systems, cloud computing, analytics, system modernization, architecture documentation, technology selection. 

Professional Background

At the SEI, John is currently

  • Principal Investigator for research to bring stakeholder preferences into the analysis of alternatives in system modernization projects.
  • Leading a team that is helping a US government agency improve their technical and governance approaches for enterprise data management.  

His past contributions include:

  • Principal Investigator for research on architecture approaches for big data systems. We created a lightweight, evidence-based technology selection method and a knowledge base that links big data architecture principles to specific NoSQL and NewSQL implementations, and characterized big data architecture patterns with a focus is on runtime observability. Applied these methods to help a US government agency assess NoSQL technologies for a new healthcare IT system.
  • Helped a research centre in Australia create a reference architecture for big data systems in the national security domain. The reference architecture is being used by MOD and Australian Federal Police.
  • Led the SEI team analyzing big data technology for a US government customer. The team used focused prototyping to collect and analyze performance and dependability data of NoSQL technologies for a new set of IT systems for healthcare.
  • Led the SEI team that assessed analytics enterprise architecture at a large healthcare provider/payer/research organization. Taking an ultra-large-scale system perspective, the team developed recommendations that resulted in a $100M investment by that organization to develop a new analytics infrastructure and applications.
  • Principal Investigator for a DOD-funded research project that developed quantitative economic-based approaches to prioritizing features for platform-based system architectures, when feature adoption by all users is uncertain. This project also developed a catalog of system integration architecture patterns, based on the concerns that arise when developing and evolving systems of systems.
  • Member of the SEI team that assisted Bursatec (the technology arm of the Mexican Stock Exchange) in the development of a new trading engine. The project applied the TSP to execute an iterative architecture design process and provide visibility into the team's progress. The system was delivered into production on schedule and within budget.
  • Led architecture evaluations for several systems, in domains ranging from health information exchange (HIE) gateway to real time command and control (C2). Each evaluation assessed how the system architectures supported business and mission goals, identified risks, and recommended remediation options.
  • Principal Investigator for DoD-funded research project that developed a model and approach to assess architecture capability at the organizational, team, and individual level, and piloted the approach for a system development team at a large aerospace organization.

Prior to joining the SEI in 2008, John was a chief architect at Avaya, Inc. There, his responsibilities included development of multimodal unified communications applications, enterprise communications analytics architectures, and the creation and enhancement of the Customer Interaction Product Line architecture. Prior to that, John was a software architect at Quintus, where he designed the first commercially successful multi-channel integrated contact center product and led the product technology integration as Quintus acquired several companies. Before joining Quintus, John worked for several companies in the video conferencing and video networking industry. He began his professional career at Raytheon, where he developed hardware and software solutions for radar signal processing, multi-spectral image processing, and parallel processing architectures and algorithms.

Publications (recent or significant)

J. Klein, R. Buglak, D. Blockow, et al., “A Reference Architecture for Big Data Systems in the National Security Domain,” in Proc. 2nd Int. Workshop on BIG Data Software Eng. (BIGDSE'16), Austin, TX, USA, 2016, pp. 51-57. doi: 10.1145/2896825.2896834

J. Klein, I. Gorton, L. Alhmoud, et al., “Model-Driven Observability for Big Data Storage,” in Proc. 13th Working IEEE/IFIP Conf. on Software Architecture (WICSA 2016), Venice, Italy, 2016. doi: 10.1109/WICSA.2016.27

J. Klein, I. Gorton, N. Ernst, et al., “Application-Specific Evaluation of NoSQL Databases,” in Proc. IEEE Big Data Congress, New York, NY, USA, 2015, pp. 526-534. doi: 10.1109/BigDataCongress.2015.83

I. Gorton and J. Klein, “Distribution, Data, Deployment: Software Architecture Convergence in Big Data Systems,” IEEE Software, vol. PP, no. 99, 18 March 2014. doi: 10.1109/MS.2014.51

"What is Architecture" (with David Weiss). Chapter in Beautiful Architecture, Spinellis and Gousios, editors. OReilly Media, Jan 2009. (

US Patent 6,934,381, "Contact routing system and method"

US Patent 6,934,381 "Method and apparatus for synchronizing transcripts and recordings of a bridge conference and using the same to navigate throgh the recording"

US Patent 9,165,260 "Method and apparatus for using estimated travel time to schedule an event and event reminders"


  • Master of Engineering (ME), Electrical Engineering, Northeastern University
  • Bachelor of Engineering (BE), Electrical Engineering, Stevens Institute of Technology

Professional Memberships

  • IFIP WG 2.10 Software Architecture, Secretary
  • ACM, Senior Member
  • IEEE Computer Society

Courses I Teach

  • Leading the development and delivery of the "Big Data Architectures and Technologies" course
  • Leading the evolution and delivery of the SEI's "Documenting Software Architectures" course, (Part of the Software Architecture Professional curriculum)
  • Deliver Software Architecture: Principles and Practices

Contact John Klein