Preston Guillot

Staff Software Engineer
Languages Scala, TypeScript, PHP, C#, F#, SQL
Infrastructure Kubernetes, Apache Kafka, Google Cloud Platform, Docker
Databases MySQL, MongoDB, SQL Server, Oracle, Spanner, BigQuery
Frameworks & Tools Splunk, New Relic, Claude Code, WCF, Web API, Git
Practices Distributed Systems, Microservices, SOA, TDD, Agile / Scrum, SOLID

Staff Software Engineer with 18+ years of experience designing and building distributed, highly scalable systems — from healthcare data platforms to large-scale fintech infrastructure. Currently serving as lead architect of Credit Karma Money, a neobanking product serving millions of members, with deep expertise in Scala and TypeScript microservices, event-driven architecture on Kafka, and cloud infrastructure on GCP. A consistent engineering leader: technical mentor, team lead, and driver of cross-team architectural decisions.

Credit Karma Mar 2016 – Present · Charlotte, NC & San Francisco, CA
Staff Software Engineer Jun 2023 – Present
Charlotte, NC
  • Lead architect of Credit Karma Money, a neobanking product offering checking, savings, and financial services to millions of members.
  • Define and drive technical architecture across a suite of Scala and TypeScript microservices deployed on Kubernetes, working closely with engineering leadership on roadmap and system design strategy.
  • Partner with product, data, and platform teams to ensure architectural decisions are coherent, scalable, and aligned with long-term business goals.
Senior Software Engineer II Mar 2019 – Jun 2023
Charlotte, NC
  • Acting engineering lead for CK International; successfully launched Credit Karma UK in 2020, expanding the platform into a new market with a containerized PHP 7 backend and hapi.js middleware.
  • Transitioned to CK Money and built out a significant portion of its fraud prevention infrastructure, including a Drools-powered rules engine, internal administrative tooling, and a real-time debit authorization system capable of making accept/decline decisions on in-flight transactions.
  • Reduced backend load by 80% by identifying and eliminating redundant frontend API calls and introducing a caching layer to cut unnecessary round trips.
Senior Software Engineer Mar 2016 – Mar 2019
San Francisco, CA
  • Joined the Credit Ecosystem team, owning backend processing and delivery of credit report data across Credit Karma's 100 million+ member base — including architecting a batch pipeline to proactively refresh the entire user base's credit data rather than only on-demand.
  • Led architectural efforts to decompose monolithic functionality into independent microservices, establishing patterns adopted across the broader engineering organization.
  • Took on engineering lead responsibilities for CK Canada (later CK International), overseeing feature development, architecture, and monetization strategy for the Canadian market.
  • Led the internationalization effort to translate the CK Canada platform into French for launch in Quebec — to this day the only multi-language surface across Credit Karma.
  • Mentored junior and mid-level engineers, contributing to team growth, code quality culture, and engineering best practices.
Practice Fusion Feb 2015 – Mar 2016 · San Francisco, CA
Senior Software Engineer
  • Built API and backend services for a high-volume EHR platform recording 250,000+ patient visits daily, using C# with WCF/Web API, ActiveMQ, and a mix of relational and document databases.
  • Led migration from ICD-9 to ICD-10 clinical diagnosis coding and spearheaded the production deployment of MongoDB for patient flowsheets.
  • Delivered new services enabling delivery of patient medical records to third parties for clinical trial matching.
Clear Lines Consulting Jun 2013 – Feb 2015
Consultant – Primary Developer
  • Led implementation of an iDesign-based SOA platform for the investment arm of a large insurance organization, enabling portfolio optimization against configurable targets via a third-party solver engine.
  • Guided a team inexperienced in service-oriented architecture to a successful delivery, introducing modern source control (Git) and CI (TeamCity) practices.
Slalom Consulting Jan 2010 – Jun 2013
Developer
  • Built financial planning tools for a global retail client — VSTO/Excel-based platform backed by WCF services and SSAS, including automation of cross-system business processes using Quartz.NET scheduling.
  • Developed a SharePoint 2010 member portal for a major news organization, providing partners visibility into content performance via OLAP data and Silverlight applications.
EMC2 Aug 2007 – Jan 2010
Software Engineering Consultant
  • Delivered custom SharePoint and web-based applications across financial services, high-tech, and communications clients — including sole development of a trading restriction logic engine and lead architect on an eleven-workflow HR and patent processing solution.
Globalstar Oct 2006 – Aug 2007
Associate Developer
  • Automated billing department processes in Perl and designed SOX 404-compliant reporting and logging tooling following Globalstar's IPO.
B.S. Computer Science
University of Southern Mississippi