Jakob Külzer
Professional Summary
Experienced software engineer with 15+ years of experience operating and developing distributed systems, performance optimization, infrastructure, and fullstack web development. Operations-focused mindset with focus on minimizing system failure modes, reducing operational overhead, and improving code quality.
I like to make things go fast, safely.
Work Experience
Wealthsimple
Toronto, Canada
Senior Software Developer, Datastores
Mar 2026 - Present
Shopify
Toronto, Canada
Senior Software Engineer, Database Platform
Apr 2022 - Present
- Implemented automation for Zookeeper ensemble maintenance and cluster migrations
- Operating and maintaining Shopify's ZooKeeper fleet; created playbooks, procedures, support for teams writing ZooKeeper clients
- Performance improvements on inhouse binlog streaming and filtering engine
- Optimized ZooKeeper cache frontend and drastically reduced memory and CPU requirements
Senior Software Engineer, Data
Sep 2020 - Apr 2022
- Implemented schema diff for data extractor to reduce full imports and save resources
- Designed and implemented API data ingestion framework and jobs for all of Shopify
- Ingestion pipeline configuration project
Data Engineer, Data Platform
Feb 2018 - Sep 2020
- Architected and implemented Shopify's new data ingestion tool
- Improved stability, code quality, maintainability, and reduced operational toil of existing statement based data extractor
Software Developer
Feb 2015 - Aug 2018
- Extended and maintained Shopify's RESTful APIs
- Frontend development for Shopify's Embedded App SDK
- Improvements to webhook platform, authentication layer
Critical Mass
Toronto, Canada
Senior Software Developer
Aug 2012 - Aug 2014
- Planned and implemented complex multi-language automotive web property
- Tech talks on various topics, including continous integration, maven, etc.
- Won Critical Mass’ CMVP award for outstanding work
Software Developer
Feb 2011 - Aug 2012
- Development of complex multi-language, multi-national CMS in the automotive space
- Implemented core framework for high performance fully interactive automotive web properties
- Custom tooling to streamline developer workflows
- Established development best practices including tagged released and automated testing
Mindblossom
Toronto, Canada
Software Developer
Feb 2009 - Aug 2009
- Microsite Development with Groovy on Grails
- Frontend Development with Adobe Flex
- Database change management
Software Developer Intern
Aug 2008 - Jan 2009
- Microsite Development with Groovy on Grails
OptimaBIT GmbH
Munich, Germany
Freelance Consultant, Security
Feb 2018 - Present
- Security Pentest (blackbox/whitebox)
- Code reviews (focus Security)
- Instructor for Java and XML
- Software development
- System administration (Linux)
Education
Bachelor of Science in Computer Science
2007 – 2009
Fachhochschule München