Timeless engineering for an ephemeral world
Freelance Web Engineer in Baltimore, MD
I’m Teejay VanSlyke, a freelance web engineer in Baltimore, Maryland. I help established organizations build websites that last. I take a user- and design-centric approach to my engineering practice, interested in why more than what or how. Read more about my philosophy of engineering.
If you’re building something for the web but can’t make sense of our new agentic world, are nervous when someone says “just vibe code it”, or just want a seasoned professional in your corner who can help you tell the signal from the noise, I can help.
I have twenty years’ experience designing, building and shipping high-quality, production-ready software for the web. Using agents to build your new project but concerned there may be hidden bugs or security vulnerabilities? I can help you to spot them and squash them for good. Spent months vibe-coding a prototype but unsure how to give it the finishing touches it needs to succeed? Let my trained eye have a look and give you honest insights your LLM might have missed.
For the majority of my career, I’ve parachuted into existing engineering teams to help them build new features, implement best practices, refactor existing code, improve deployment processes, and more. I’m able to hit the ground running on any project and love learning about new project domains.
Are you an entrepreneur who wants to build a new web application, but are worried your vibe-coded app is riddled with bugs, or worse, security holes? While it makes sense to hire a full-fledged agency if you have the startup capital to do so, it can be expensive if you’re bootstrapping a new idea. I can help you build an attractive minimum viable product (MVP). I started my career helping entrepreneurs build web applications from start to finish, and I’m happy to walk you through the process.
I am currently accepting new engineering clients. Contact me for a free fifteen minute consultation.
Selected testimonials
You're probably not going to find anyone better than Teejay that's available for hire. Don't pass up the opportunity to work with him!
— Dan Lucas, Emerge Interactive
There is nothing that would stop me from working with Teejay again. In fact, working with him has ruined me for working with other less capable developers.
— E.J. Coughlin, Hype Social Read case study
Teejay did an amazing job of exceeding our expectations. I was able to engage with him immediately. And he made a big impact, fast.
— John Eberly, Chatlio Read case study
Selected experience
DevelopmentNow — Portland, OR — 2018-2026
- Built a supplemental women's health and fertility insurance platform for web and mobile using React, React Native, Node.js, and Flutter, enabling users to manage coverage and claims across devices.
- Built and maintained Django/React-based platform powering COVID-19 testing sites for the state of Massachusetts, processing over 1,700,000 patient tests.
- Authored custom Jupyter notebooks to provide monthly insights into patient data for state reporting.
- Oversaw successful sunset of the service, with careful consideration of sensitive HIPAA-compliant patient data.
- Implemented SAML-based SSO solution to integrate authentication post-acquisition, consolidating identity management.
Docnote — Canada — 2024-2025
- Provided senior technical consulting and architectural guidance for a healthcare platform serving Canadian physicians.
- Advised on technology strategy and system design for a platform that streamlines uninsured service requests, patient communication, and payment processing for medical practices.
- Consulted on technical direction for a product operating in a regulated healthcare environment, balancing compliance requirements with rapid feature delivery.
Emerge Interactive — Portland, OR — 2017-2019
- Engineered frontend of internal sales pipeline platform for multinational IT services company in React and Redux.
- Built frontend for political donor search platform with React and Redux featuring a generative user interface for building complex filter queries.
PS Dept. — New York, NY — 2012-2017
- Developed marketplace ecommerce Rails API for an on-demand personal shopping and luxury concierge service processing millions of dollars in customer sales.
- Built React-based client request and order fulfillment pipeline and internal backoffice tool for servicing styling customers and automating style team tasks.
- Conducted peer reviews and provided constructive technical guidance.
- Read case study