David Steinbroner

Product manager who prototypes, codes, and ships. I've taken features from an abstract idea to production at a fintech startup, and I spend my free time building apps and learning new tools. I build things for people, not users.

Case Studies

Fold

Shipping Tax Season at a Startup

Fold launched bitcoin selling in 2024, which meant ~5,000 users needed tax documents by mid-February 2025. By December, they were already getting tax emails from Coinbase and wondering where Fold's was. I picked it up in November with no crypto tax experience, figured it out, coordinated across legal, compliance, finance, engineering, two custodians, and TaxBit, and shipped in 10 weeks with 2 engineers and a junior designer. A month ahead of deadline.

Fold

Completing the Bitcoin Flywheel, and Paving the Way for IPO

Fold users could already earn and buy bitcoin. Once we added Buy, we were competing with Strike and Coinbase — and we were missing table stakes. I built the Figma prototypes, worked across two custodians with completely different APIs, and leaned on the 40k-member Discord I'd helped build to understand what users actually needed. Shipped Sell, Receive, and Direct to Bitcoin over six months. Trade volume jumped 50%.

Fold

The Most Public Feature at the Company, and I Had to Make It Worse

Fold's Spin Wheel was the company's most beloved feature and its biggest financial liability. I inherited it, tried eight different approaches over 18 months — some too complex, some that made finance happy but confused users — and eventually learned the hard way that simplicity wins. The final model: one wheel, flat prizes, works at any Bitcoin price up to $1M, and still drives 50k daily spins.

Fold

No Bandwidth? Ship It Anyway

The community had been asking for notification preferences for three years. At a startup, bandwidth is always the blocker. So I found a way to ship it without engineering.

Personal Projects

An AI-Powered TTRPG That Removes the Human Barriers

Tabletop RPGs have two accessibility problems: trying new things with strangers is intimidating, and traditional fantasy isn't for everyone. AI happens to solve both — you can play alone, and it can build any world you want. I built Story Mode to see if that actually works.

Personal Projects

When the Integration Doesn't Exist, Build It

Pokemon GO doesn't let you export your collection data. No API, no export button. I built an automated pipeline: Python drives screen mirroring, AI vision reads the screenshots, local math crunches the numbers, and a web UI makes it all usable. The kind of integration you build when the integration doesn't exist.

Building

Story Mode— AI-powered TTRPG that removes the two things keeping people out of tabletop gaming: playing with strangers and being stuck with fantasy. AI runs the game.
POGO PAL— Pokemon GO helper for casual players. Most Pokemon GO sites are built for hardcore players; this one isn't. Also a fun UI experiment. The scanner and collection tools live in a separate case study.
Discovering Magic— A gateway to Magic: The Gathering through things you already love: Fallout, dinosaurs, anime art, Furby cards. Discovery over terminology. Currently under construction.
Local Gov Watch— Follow what your local government is actually doing. Meeting summaries, decisions, votes, without digging through PDFs. Currently under construction.
This Site— Building my portfolio in public with Next.js and Linear. View on GitHub →

Built