John Jung

I’m John. I build AI systems and small, useful products.

My work has moved through cosmic-ray data, clinical bioinformatics, email infrastructure, and now AI engineering. The thread is pretty consistent: understand the system, make the interface clearer, and ship something people can use.

Currently working on AI engineering at MGX and keeping a small lab of projects across developer tools, productivity, finance, and agents.

Now

Current work, kept simple.

AI engineering at MGX

Building applied AI systems with a bias toward reliable interfaces and useful loops.

Side-project lab

Developer tools, productivity, finance, and agents.

Interested in

Useful agents, reliable AI systems, product craft, and small tools.

Timeline

A restrained archive of the path here.

The through-line has been data, interfaces, systems, and shipping useful things.

  1. Early work

    NASA Goddard / University of Maryland

    Built and analyzed cosmic-ray data systems, where the work was mostly about signal, noise, instruments, and patience.

  2. Clinical data

    NYU Langone / University of Rochester

    Graduated at 19, then spent several years on clinical and research bioinformatics datasets, contributing to 30+ publications.

  3. Product studio

    Pith Studio

    Built product work for startups and larger companies, including Fortune 500 client work, with a focus on making rough ideas usable.

  4. Email systems

    june.ai, then Nylas

    Started june.ai, an AI-first email app acquired by Nylas, then worked on email and productivity infrastructure at Nylas.

  5. Now

    MGX

    Working on AI engineering and keeping a small shelf of practical experiments moving.

Selected Projects

A project shelf, not a trophy case.

A few useful tools and experiments from the lab, written as notes on what they are and why they exist.

Webhook Rodeo

webhook.rodeo

ActiveDeveloper tools

Webhook infrastructure, but with a better debugging loop: receive, transform, route, and replay events.

Why: Webhooks are everywhere, but debugging them still feels worse than it should.

Receptive

withreceptive.com

ActiveAgents

An AI answering service for catching missed calls and turning them into useful follow-up.

Why: Phone calls are still where a lot of important work slips through.

Stride Systems

stride.systems

ActiveAgents

AI agents for operational follow-through across tickets, docs, and team pings.

Why: The value is in closing the loop after the model produces a suggestion.

skeet.build

skeet.build

ExperimentDeveloper tools

A small bridge for connecting Cursor to MCP tools.

Why: Good agent tools should make context feel local and easy to wire.

check.supply

check.supply

ActiveFinance

A mobile-first way to send paper checks without envelopes, stamps, or post-office errands.

Why: Old financial rails still need clear interfaces.

june.ai

june.ai

AcquiredEmail

An AI-first email app, later acquired by Nylas.

Why: Email is a messy coordination system; the question was how much of it could feel calm.

Open

Lab Archive

Smaller experiments, still part of the shelf.

  • Collective

    Shared budgeting, expense management, and spending controls for groups.

    ExperimentOpen
  • MyWalletPass

    Turns membership, library, park, gym, and club cards into Apple Wallet passes.

    Weekend buildOpen
  • Buoy Club

    Social listening for creators, founders, and teams in the Farcaster ecosystem.

    ExperimentOpen

Notes

A few working notes.

Short entries about building reliable AI products, small tools, and the path from research data to product systems.

What makes an AI product feel reliable?

Reliability in an AI product is less about sounding certain and more about showing the user where the system is, what it knows, and what happens next.

Principles

A small operating list.

  • Useful beats impressive.
  • Ship, then refine.
  • Systems over demos.
  • Taste is care.
  • Stay close to the material.

Elsewhere

Other places to find the work.