# Westin Wrzesinski > Senior Staff Software Engineer at Shopify Location: Greater Chicago Area, United States Profile: https://flows.cv/westin I am a polyglot software engineer with a strong emphasis on the JavaScript ecosystem. I have a strong passion for mentoring and growing engineering teams. I enjoy collaborative and transparent environments as I believe we are all in this together. Notable Experience includes: - W3C Payment Group Participant - TC39 Delegate - API Design and Architecture with NodeJS, Python (FastAPI), Ruby on Rails, and Java - Built new web payments SDKs at PayPal - Built and maintained a Rich Text Editor engine for Sprout Social. Rendering engine leveraged React - Built various mapping and analytics tools with WebGL and React Interests include: - Browser based Payments - Web Components - Functional Programming usually in OCaml - Type Systems - React - gRPC ## Work Experience ### Senior Staff Software Engineer @ Shopify Jan 2024 – Present | Chicago, Illinois, United States ### Principal Software Engineer @ PayPal Jan 2024 – Jan 2024 | Chicago, Illinois, United States Responsible for all things SDKs at PayPal and Braintree. 2500M button renders per month moving $4500M in payments a month. ### Senior Staff Software Engineer @ PayPal Jan 2021 – Jan 2024 | Chicago, Illinois, United States Tech lead for PayPal and Braintree Web SDKs ### Lead Web Engineer @ SpiderRock Jan 2020 – Jan 2021 | Chicago, Illinois, United States Lead of the engineering team that built new services and progressive web apps for options trading - NodeJS Services with gRPC - Nomad and Consul - React Component Library for web and mobile - D3 and framer-motion for market visualizations ### Senior Software Engineer @ McKinsey & Company Jan 2020 – Jan 2020 | Greater Chicago Area Designed and Architected an internal solution for quickly taking CSV or Postgres datasets and generating React web apps to filter and visualize the underlying data Designed and built Domo data pipelines and visualization portals for the US Covid Initiatives Designed and built Python APIs and React/Elm Frontends for the Advanced Industries (Automotive) Practice ### Staff Software Engineer @ Sprout Social, Inc. Jan 2017 – Jan 2020 | Greater Chicago Area Worked as a leading engineer on the Publishing team which focused on managing content creation, scheduling, and permissions/approval flows for our users. Technologies used include: React with Redux, Flow, Python via Django, and Java via DropWizard - Mentored numerous engineers on both the Front End team as well as Backend teams - Started the new React Component Pattern library which later powered the application redesign just prior to our IPO event - Led JavaScript Guild, which focused on keeping the team up to date with JavaScript best practices and libraries. - Organized Accessibility events where Front End Engineers focused on ways to improve the a11y of our main application - Wrote rich text editor framework which included Social Media Mention completion for all major networks, asynchronous link metadata scraping, hashtag autocompletion and recommendations based on social network activity, and a robust and fancy emoji picker - Updated the app to handle users with multiple thousands of connected social profiles. This work included writing new Profile selection widgets. Accessibility and performance was a main focus - Patched security vulnerabilities in NodeJS Services ### Solution Architect @ Slalom Consulting Jan 2016 – Jan 2017 | Greater Chicago Area Architecting new React applications for clients and mentoring Slalom engineers in both NodeJS and React. Served as Technical Lead and Mentor on numerous client engagements Some Notable Client Experience: --------------------------------- 1. Apple Maps: * Managed team of both Apple and Slalom engineers to rewrite internal diagnostic and dashboard tooling which leveraged React and WebGL. Focused on high-performance rendering and showing hundreds of thousands of data points efficiently on single pages. * Taught Apple Employees how to leverage React and Redux, as well as, orchestrated a migration path from Backbone to React and WebGL (for data-intensive maps). * Wrote React API on top of WebGL mapping tools to improve the developer experience * Helped migrate towards a Component Library for commonly used React components * Wrote internal Elastic Search query builders to be used by non-technical team members 2. Sundae Collective by 72 and Sunny * Managed team of 5 Slalom Engineers * Leverage Koa, Postgres, React, and other tools to build a component library as well as a social network for creatives to interact with and enter contracts with various big brand retailers 3. Food Genius (US Foods acquisition): * Worked to reverse engineer Go and Python tools and APIs to stand back up infrastructure * Updated React Web Applications * Worked on Menu OCR tooling to more rapidly retrieve and store menu data from local restaurants * Updated and maintained existing AWS infrastructure ### Senior Software Engineer @ Slalom Consulting Jan 2014 – Jan 2016 | Greater Chicago Area Primarily focused on working with clients to architect and implement React apps with either a basic Flux pattern or leveraging Redux. Assisted on the implementation of NodeJS Apis using Express and Koa. As well as working to a smaller degree with Java Spring backends. Some Notable Client Experience: --------------------------------- 1. Slalom (Internal Project): * Led Modern Web Guild as a place for engineers across Slalom offices to share learnings and anecdotes from the JavaScript and web communities which included: React, Vue, NodeJS, Elm, GraphQL, and many other technologies * Created and ran a React Bootcamp in which I taught Slalom employees and later external clients how to move Frontend Applications to React and best practices from the ecosystem. This class was given at every Slalom Technology Hub by myself at first and later a team of other Slalom engineers. * Worked with new hires to the Chicago office to onboard them to Slalom and to the Modern Web practice 2. HCSC/Blue Cross: * Led efforts to create new web applications using React, which at the time was just released * Helped train both Slalom and Blue Cross Engineering teams on React best practices * Wrote form management library to maintain state and provide consistent and easy to use validation using React * Wrote statement solution based on the Flux architecture as at the time there were no solution in this space * Worked on Spring Boot API to provide authentication and authorization to new product suite * Advised and collaborated on microservice architecture leverage Java Spring and MongoDB 3. Hyatt: * Led efforts to refresh and harden a NodeJS + Express WiFi portal application used across the hotel chain ### Senior Software Engineer @ BLiNQ Media Jan 2014 – Jan 2014 Assisted in the ShopLocal acquisition of BLiNQ Media. Assisted in stabilizing and adding new features to the Ruby on Rails APIs for the Facebook Ad Manager Dashboard. ### Software Developer II @ Shoplocal Jan 2013 – Jan 2014 Architected AutoLiFT as a platform for car dealerships to launch customized and targeted Facebook Ads. Leveraged Ruby on Rails, Sidekiq, and Postgres to create the product. Worked with Blinq Media during the Gannett acquisition to add stability and features to the existing Ruby on Rails APIs. Developed newest iteration of SmartCircular Weekly Ad Framework using Angular 1.1.2 for client side development and C# .NET for server side api. This included writing many custom solutions for impression tracking, SEO, and library of custom Angular modules. All fully responsive and using AMD JavaScript patterns. Maintained JavaScript MVC platform. Recommended and upgraded the 'lite' version of SmartCircular sites for small retailers to spawn new sites with simply a JSON file and CSS stylesheet. Angular 1.2, NodeJS, and Grunt were used to develop the platform. Sold to many small scale retailers around the United States. Implements deep linking, user tracking via Webtrends, and fully responsive design. Developed a publisher widget app to display big box retailer's weekly ad circulars on a sidebar ad. This widget was written in javascript and loaded an iframe to a c# .net mvc app containing the weekly ad of the retailer chosen as well as location change options and retailer change options. Was implemented in AOL mail with an expected 30 million page views. ### Software Developer @ Shoplocal Jan 2012 – Jan 2013 | Chicago Using .Net MVC, JavaScript, CSS 3, and HTML 5 to create feature rich weekly ad sites for large to small scale retailers. Leveraging Agile methodologies to work with large teams of developers, designers, and quality assurance. ### Software Developer Intern @ Shoplocal Jan 2011 – Jan 2012 Worked with Adobe Flex, C# MVC HTML, CSS, JS, and JQuery to make retail websites. Gained experience with Agile methodologies. ## Education ### Engineering in Computer Science University of Illinois Chicago Jan 2008 – Jan 2012 ## Contact & Social - LinkedIn: https://linkedin.com/in/westinwrzesinski - Website: http://westinwrzesinski.com --- Source: https://flows.cv/westin JSON Resume: https://flows.cv/westin/resume.json Last updated: 2026-03-22