Open to new roles
Kevin Yang
Full-stack software engineer with 6+ years in TypeScript, React, React Native, Node.js, and GraphQL.
I spent five years at OTTO Sport AI owning the league scheduling engine, and I'm now building iOS apps in React Native.
Selected work
OTTO Sport AI · 2021 to 2026
League scheduling engine
Technical owner of the engine that builds season schedules for youth sports leagues, running on a platform of 50+ independently deployed microservices.
I led its architecture and coordinated 2 to 3 engineers on matchup generation.
- Manual scheduling time
- Up to 75% less
- Generation, 1,000+ games
- 30s to about 5s
- Test coverage
- Under 20% to about 80%
- Built the conflict engine that fits games into open slots using per-grouping rules for games per team, dates, time windows, locations, game length, and coach conflicts.
- Rebuilt conflict checks on 5 minute slots, which is where the speedup came from.
- Designed matchup generation around the Strategy pattern so new league formats needed no scheduler changes.
- Rebuilt legacy V1 scheduling features in V3, helping move the last 3 large clients off V1.
iOS app · 2026
Recipe Book
Turns cooking videos into recipes with Gemini, then keeps them in a library with meal plans and shopping lists. Includes Sign in with Apple and subscriptions. In final QA ahead of App Store release.
React Native · Expo · NestJS · MongoDB · Gemini API
Full-stack · 2026
A Trello style board with drag and drop within and across columns, built as a TypeScript monorepo with a NestJS API and Playwright end-to-end tests.
React 19 · Vite · Tailwind · dnd-kit · TanStack Query · NestJS · Prisma · PostgreSQL
Test automation · 2026
85 UI, API, and accessibility tests for an open source e-commerce app. Every push starts a clean copy of the app in Docker, seeds it, and runs the suites in GitHub Actions.
Playwright · TypeScript · Pytest · Zod · axe-core · Docker
Experience
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2021 to 2026
Software Engineer, OTTO Sport AI
Formerly Demosphere
- Owned the league scheduling engine and embeddable schedule and standings widgets, keeping API contracts and migrations backward compatible across services.
- Built live game tracking in React Native with PubNub and MongoDB, syncing scores and timers across devices.
- Extended the Ruby CMS so organizations could embed widgets on their own sites.
- Led production deployments and rollbacks, and handled on-call triage of 5 to 10 issues a week.
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2020 to 2021
Software Engineer, DCS Business
- Built full-stack IoT monitoring with live and historical sensor views across every location a business had, using MQTT, Socket.io, and MySQL.
- Added email alerts through AWS SNS and Nodemailer with configurable thresholds, event counts, and time windows.
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2019 to 2020
QA Engineer, Hive Media Group
- Smoke tested every UI change across about 25 publishing sites and automated parts of it with Selenium.
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2017 to 2019
Accounts Receivable, FirstService Residential
- Handled delinquency actions on homeowner accounts across 40+ HOA communities before moving into software.
Stack
TypeScript, JavaScript, SQL, Ruby, React, React Native, Next.js, Node.js, NestJS, GraphQL, REST
Data and cloud
MongoDB, PostgreSQL, MySQL, Redis, Prisma, AWS (S3, SNS, CloudWatch), Grafana, Firebase
Tooling
Git, GitHub Actions, Docker, Jest, Mocha, Playwright, Selenium, Claude Code, GitHub Copilot, ChatGPT
Education
LearningFuze, Software Engineering Immersive, 2019
UC Riverside, BS Business Administration, 2016