Software Engineer Senior

Garfield Lewis

Senior Software Engineer

********.*****@*****.*** 416-***-**** https://www.linkedin.com/in/garfieldlewis

Professional Summary

Results-driven Senior Software Engineer with over 35 years of experience in designing, building, and optimizing software systems across industries. Expertise in C/C++, assembler, system-level programming, debugging, and performance tuning. Proven track record in relational database internals, SaaS system architecture, multi-threaded development, and cross-platform solutions. Strong collaborator with a history of successful product launches and technical leadership.

Technical Skills

Languages: C, C++, Python, Assembler (x86, x64, IA64), Bash, SQL, PHP, Perl, HTML, CSS, Java, JSON, XML

Frameworks & Tools: AngularJS, Visual Studio, VSCode, Git, CMake, GNU Make, Jenkins, Jira, Confluence, GDB, WinDBG, VTune, perf, Docker, Valgrind

Databases: DB2, PostgreSQL, MySQL

Platforms & OS: Linux, Windows, AIX, OS/2

Methodologies: Agile Development (sprint based approach), Clean Code, Code Review, Mentoring, Collaboration, Software Profiling

Specialties: Performance Tuning, Debugging, Multi-threading, Security, Compilers, SDLC

Professional Experience

Senior Software Engineer

LzLabs GmbH 09/2016 – 07/2025

Led development of relational database (RDB) subsystem using PostgreSQL.

Engineered key DB2z compatibility features including encryption and data type support.

Designed and implemented APIs and security/authorization layers.

Built GDB disassembler extension for z/OS in Python reducing debugging time by 50%.

Developed primarily in C and C++.

Technologies: C, C++, PostgreSQL, Python, Linux, Git, Jira, CMake, Jenkins, JSON, XML, Docker, Valgrind,

Chief Software Architect & Engineer

Flow Healthcare 05/2014 – 09/2016

Co-founded company and designed a SaaS solution for medical procedure reporting.

Full-stack development using PHP, MySQL, HTML, CSS, AngularJS, and LAMP.

Implemented version control, issue tracking, and CI/CD pipelines.

Technologies: PHP, AngularJS, MySQL, Linux, Bitbucket, Jira, Bamboo, Git

Software Engineering Manager

Vital Insights 04/2014 – 08/2014

Managed development of Foresight SaaS platform used in automotive customer surveys.

Directed road map for next-generation application in Windows .NET stack.

Performed team evaluations and mentored junior engineers.

Technologies: Windows, .NET, Agile, Leadership

Senior Software Developer

IBM Canada Software Lab 01/2012 – 07/2013

Developed DB2 V10.5 SIMD abstraction layer for BLU Acceleration increasing performance by greater than 20% on the IBM Power platform and 15% on Intel.

Increased data compression by more than 90% if stored in columnar tables.

Enabled cross-platform performance optimization (Intel, AMD, IBM Power).

Technologies: C, C++, Assembler, SIMD, AIX, Linux, Windows, GDB, Visual Studio

Senior Developer – DB2 pureScale

IBM Canada Software Lab 10/2008 – 01/2012

Owned problem determination for DB2 pureScale’s shared-everything architecture.

Built automatic diagnostic data collection across multi-node setups.

Technologies: C, C++, Linux, AIX, Windows

Senior Developer – DB2 Windows Development

IBM Canada Software Lab 07/2000 – 10/2008

Ported DB2 to Windows 64-bit and IA64 platforms; wrote custom assembly routines.

Led implementation of Extended Security features in DB2.

Collaborated with Intel, AMD, Microsoft.

Technologies: C, C++, Assembler, Windows Security, IA64

Senior Developer – DB2 Performance

IBM Canada Software Lab 02/1997 – 07/2000

Focused on performance optimization and compiler enhancements for DB2 on Windows.

Technologies: C, Performance Tools, Benchmarking, Windows

Associate Development Analyst – DB2 Integration

IBM Canada Software Lab 08/1995 – 02/1997

Led DB2 integration with third-party solutions and WORM device prototyping.

Associate Development Analyst – VisualAge C++

IBM Canada Software Lab 06/1992 – 08/1995

Maintained VisualAge compiler and debugged code generation issues.

Technologies: C, C++, OS/2, Windows, Assembler

Associate Development Analyst – MVS/VM Support

IBM Canada Software Lab 07/1989 – 06/1992

Supported MVS/VM systems; developed IDSS/CMVC bridge in C and REXX.

Education

Bachelor of Computer Science

York University – Toronto, ON 09/1985 – 05/1989

Awards & Recognition

Outstanding Technical Achievement Award, IBM Canada (2005) – For implementation of Extended Security for DB2 for Windows

100GB TPC-H Benchmark, Intel Corporation (2003) – For Itanium2 benchmark contribution

World Record TPC-C Benchmark, IBM Canada (2000) – For DB2 on IBM Firestorm system

Compiler Optimization Award, Intel Corporation (2000) – For enabling Intel C++ Compiler migration and performance gains

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