Sean Madrid, technical product manager.

APIs, developer experience, and the infrastructure agents run on.

Most recently costQL, which prices an API call before an agent fires it.

See how it worksSee past work
now // shipping
costQL — PRICES ANY QUERY BEFORE IT RUNS NETWORK CALLS — 0 (FULLY OFFLINE) DISTRIBUTION — PIP INSTALL COSTQL · NPM I COSTQL VALIDATED ON — 3 DIFFERENT APIS
live · 2026
Selected Work01

Systems, experiences, and strategy shaped for real projects under real constraints.

Pricing InfrastructureLive
costQL banner — price GraphQL queries before they run

costQL

An offline pricing engine for GraphQL. Point it at your API once, then price any query before it runs. No server, no signup — free and open source.

PyPI + npmShipped
3 APIsValidated
Open SourceFree to run
0 serversOffline
Platform StrategyLive
OneSource Web3 API

OneSource Web3 API

Pivoting to a service-first approach, this project focused on creating scalable APIs providing blockchain data, aligning with market demands and future growth.

5→1Services
2 yrsTimeline
StripeSelf-serve
GraphQLFederated
Product Design
Hero for the On-Chain Brokerage System

On-Chain Brokerage

A new approach to NFT brokerage built from the ground up for transparency and fun.

1 unitTrade model
EscrowBuilt-in
2-personTeam
Hands-onDesign + build
View all work
How I Work02

Where this kind of collaboration fits.

01

Things move fast

Context transfers efficiently. Decisions happen in real time. Work keeps moving.

02

Genuine constraints

Limited resources mean focused scope. Legacy systems dictate integration. Tight timelines force prioritization.

03

Interdependent parts

Systems need to connect. Experiences span platforms. Technical choices affect what users see.

04

Direct collaboration

Questions get answered directly. Reasoning gets shared openly. Problems get addressed as they show up.

Competencies03

The surfaces I design and the systems I build them into.

01

API & Platform Design

Designing developer surfaces, schemas, and contracts that hold up under real integration load.

02

Agent & Machine Interfaces

Designing the surfaces agents consume: tool definitions, MCP servers, and cost controls on machine-driven calls.

03

Product Strategy & Roadmapping

Translating uncertainty into testable assumptions, then organizing work to reduce risk.

04

UI/UX Design & Engineering

Building interfaces that reveal function through form.

05

Data & Measurement

Instrumenting systems so behavior is observable and claims are checkable.

06

Cross-Functional Leadership

Orchestrating alignment through shared language and clear decision structures.

Side Projects04

Small builds made for curiosity, convenience, or someone who asked nicely.

CoQuery: AI-Powered Blockchain Query Composer

A natural language interface that translates developer intent into executable GraphQL queries, paired with curated insights from on-chain and off-chain signals.

Popup Piano Bar Songbook

A Google Sheets-powered songbook that syncs live with a custom web interface, letting a piano bar operator manage hundreds of songs without touching code.

Rankling: Task Prioritization Tool

A comparison-based prioritization tool that turns an overwhelming task list into a clear, ranked sequence of action.

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