Full-Stack Engineer · Toronto, ON
I build scalable web products end to end, from cloud data pipelines to the last pixel.
A little about me
I’m a full-stack engineer in Toronto with 4+ years building web applications. I work across the stack: TypeScript with React and Next.js up front, Python/FastAPI and AWS behind it. What I care about most is shipping features that actually move the business.
Lately I’ve been deep in AI-assisted development: building MCP servers and LLM-powered tools, and using Cursor and Claude Code day to day. I also like mentoring, running technical interviews, and taking the occasional side project further than it probably deserves.
Where I’ve worked
- May 2025 - Jun 2026Toronto, ON
Senior Full-Stack Engineer · Hotspex Media
Built an internal SaaS analytics platform and AI tooling for a media agency.
- Built an internal SaaS workflow platform (Next.js, FastAPI, PostgreSQL) that pulls together data from Meta, Amazon, and DV360.
- Built an MVP MCP server for agentic workflows over Google Ads data, and a consumer-facing GPT wrapper to generate leads for the core AI platform.
- Optimized a high-volume pipeline that processes millions of URLs a day with a new domain-scoring system, and designed a secure setup for offline-conversion data ingestion.
- Used Cursor and Claude Code to ship integration services with clear, reusable patterns.
- Nov 2024 - May 2025Toronto, ON
Senior Full-Stack Engineer · Leni
Owned AWS infrastructure and helped grow the engineering team.
- Maintained an AWS-hosted microservice architecture serving thousands of users (Lambda, EC2, Fargate), and provisioned access for all employees.
- Ran technical interviews and onboarded new engineers.
- Aug 2021 - Nov 2024Toronto, ON
Full-Stack Engineer · Leni
Built core features of a SaaS platform for property managers.
- Built an email templating system that sent 30k+ messages to leads and tenants, which cut down on lost leads and improved conversion.
- Led a state-management overhaul that cut page-load times by about 10x and made later feature work simpler.
- Led SOC2 compliance work: resolved 60+ controls across GitHub, AWS security, and IAM, and added CloudWatch metrics and alarms.
Selected projects
- TypeScript
- Discord
- LLM
- Next.js
- Avalanche
- Web3
- React
- WAX Blockchain
- NFTs
Cadence
A Discord bot for journaling, semantic search, and LLM-assisted reflection.
Helvetica NFT Drop
A contracted Web3 app for an NFT art collection built around the Helvetica typeface, with in-app credit-card purchases on Avalanche.
Chain Champs
Co-founded the first NFT marketplace on the WAX blockchain: live sales feed, price-prediction tools, and minting for collections, packs, and drops. Handled thousands of daily transactions with sub-second updates.
Let’s talk
Have something you’re working on, or just want to say hello? The fastest way to reach me is email.
hello@zackkelly.dev- GitHub@zackorykelly
- LinkedInin/zack-kelly
- Emailhello@zackkelly.dev