Simmon Li

Resume

Email: hello@crespire.dev
Located in Toronto, Ontario, Canada

Self-taught and tenacious, I’m a mid-level fullstack developer looking for an opportunity to grow with a team and continue to build on my skills. I’m fluent in Ruby/Rails, Hotwire, and Javascript. I’ve tinkered with Typescript, React and Go in my spare time and always open to learning new things.

I’d love to chat about what I can bring to the table, so contact me!.

Work Experience

Switch Growth, Senior Software Engineer

Febuary 2026 - present

Architected batch data processing pipeline optimizations reducing cloud infrastructure costs by 48%, delivering significant annual infrastructure savings across a multi-tenant SaaS platform build on Ruby on Rails, PostgreSQL, ClickHouse and Hotwire.
Eliminated tail latency in core job execution engine through data model decoupling, reducing worst-case runtime from 21 hours to 5 minutes.
Implemented resumable job processing pattern across multiple data integrations, reducing median job duration by 59-66% and p99 latency by up to 79%.
Achieved 40% more job throughput with 36-50% fewer compute hours through combined architectural improvements to the ETL pipeline and data processing architecture.

Software Engineer, November 2023 - January 2026

Developed and maintained API integrations, working across the stack to expand platform capabilities and streamline external data flows.
Guided clients through onboarding and technical challenges, consulting on roadblocks and executing technical milestones to drive client success.
Increased test coverage from ~75% to ~80% using RSpec and Capybara, strengthening stability and preventing regressions. Also migrated supporting infrastructure to improve reliability and speed.
Replaced legacy React and Javascript with Turbo and Stimulus, simplifying frontend stack and improving maintainability.
Implemented onboarding features to improve data integrity, and improving the system architecture with data schemas.

Sierra Rails, Software Developer

March 2023 - November 2023

Executed architectural changes with the tech lead, significantly reducing error rates (approximately 60%)
Built a comprehensive RSpec suite, achieving ~92% code coverage
Led development of a new checkout flow improving the app across the stack to support business goals, open the architecture for additional payment processors, and enable more checkout and payment data capture for analytics
Re-engineered search to leverage a microservice and set up deployment environments to support search service
Improved application reliability by switching asset bundling to support more browsers, improving user experience and reducing error rates due to data inconsistency
Built new features using Ruby on Rails, PostgreSQL, ViewComponents, Hotwire, Devise, Bootstrap, Rspec and Capybara
Delivered numerous new features from user stories and Figma design mocks while working across the stack as needed
Implemented new organization/brand workflow to manage sets of press releases, benefiting agency users with multiple clients and/or brands
Created an image upload feature and workflow using Turbo/Stimulus, enabling users to upload and (re)order accompanying images with their press release without full page loads, improving customer conversions
Spearheaded development of a new user onboarding experience, improving data reliability
Worked in concert with the tech lead to re-implement our AI generation approach to support future growth and flexibility
Vendored an open source Javascript package to support image uploading with new required functionality
Crafted data migrations to ensure data integrity and consistency
Maintained and updated documentation for the application

Volunteer Experience

Ruby for Good - CASA, Individual Contributor

Ruby on Rails, PostgreSQL, ViewComponents, jQuery, Devise, Pundit

Implemented UI updates to leverage JQuery Datatables for management pages to make it easier to use
Reviewed and improved multi-tenant permissions using Pundit to ensure security between tenants
Encapsulated application jobs into unit-testable plain old Ruby objects and wrote tests, adding confidence in notifications

The Odin Project, Individual Contributor

Ruby on Rails, ViewComponents, Discord.js

Contributed many curriculum updates, including: git best practices, setting up PostgreSQL for development, and using AI while learning foundations
Fixed form validation bugs on the web application and update the data to include new lessons
Fixed a points grant bug on the community discord bot

Personal Projects

Railsbook

Ruby on Rails, devise, Turbo/Stimulus, Sass CSS, RSpec, dokku, docker, AWS S3
Live: https://railsbook.crespire.dev
Repository: https://github.com/crespire/rails_railsbook

Implements core Facebook friend and content experience
Automated RSpec/Capybara test suite with ~83% coverage
Styled via custom BEM system utilizing Sass
Leverages dokku/docker on DigitalOcean for deployment. Hooks up to Sendgrid and AWS S3 for supporting services

Buysell by crespire

Ruby on Rails, React, Typescript, Tailwind, PostgreSQL, Rspec, cypress, git, docker, AWS S3, vercel
Live: https://buysell.crespire.dev/
Repository: https://github.com/crespire/buysell

Implements a full stack buy & sell application with React Typescript/Rails API
Custom hooks and providers on the React application centralize important application functions, including API access and data caching and user authentication
Styled using daisyUI built on Tailwind, with some custom components created for re-usability.

2 Player CLI Chess

Ruby, RSpec
Live: https://replit.com/@crespire/rubychess
Repository: https://github.com/crespire/ruby_chess

Implements Chess for 2 players via command line interface in Ruby
Planned and implemented from broadly scoped requirements
Automated RSpec test suite with ~96% coverage
Program does not utilize any third party Chess libraries
Wide compatibility with other Chess software via FEN (de)serialization

Education

Honours Bachelor of Arts with High Distinction (3.73/4.0 GPA)

University of Toronto
2011 - 2014

Specialization in Peace, Conflict & Justice with a minor in Ethics, Society & Law

Bachelor of Music in Performance (2.89/4.0 GPA)

University of Toronto
2006 - 2011

Specialization in Vocal Jazz

Skills

Languages: Ruby, Javascript, Typescript, HTML5, CSS3
Frameworks: Ruby on Rails, Hotwire, React, Bootstrap, Tailwind
Automated Testing: RSpec, Cypress, Jest
Deployment: Github Actions, Google Cloud Platform, AWS, Heroku, DigitalOcean
Tools: git, neovim, docker