🌐 petewatters.ie

Product engineer, 20+ years building for the web and the last decade in fintech and crypto. Frontend specialist, comfortable across the full stack.

Most recently I built LLM usage and cost tooling for a legal AI workspace: a production usage and cost dashboard across React, Next.js, Python and FastAPI, alongside the testing, review and agent tooling a team needs to ship with coding agents in production.

Products I design and ship end to end:

• Stackr: a self-custodial cross-chain portfolio terminal (BTC · ETH · SOL · Stacks). Client-side, no backend, custom SVG charts. → case study
• SimplyFPL: a real-time Fantasy Premier League product, built solo. Edge-served on Cloudflare Workers and Durable Objects. → case study
• petewatters.ie: this site. An Astro PWA with build-time on-chain data, including a live GitHub graph and a Solana-NFT avatar. → source

→ more at petewatters.ie/blog

Three years on Leather at Trust Machines, an open-source, self-custodial Bitcoin and Stacks wallet. I shipped Leather's first mobile app in React Native and Expo, reaching 1,850+ monthly active users within three months, and was a core team member on the Hiro to Leather rebrand.

• Monorepo and shared UI packages: set up packages/ui so the extension and mobile app share one component library. leather-io/mono#161
• Cross-platform feature packages: one feature package serving two surfaces, 152 files. leather-io/mono#1837
• Full-page view and container rebuild: drawer system to Radix Dialog, 358 files. leather-io/extension#4655
• Branded types for Bitcoin addresses: compile-time address safety, 47 files. leather-io/mono#885
• Secret-key redesign and BIP-39 validation: word-by-word mnemonic input. leather-io/extension#4243
• Spam and scam token filtering: phishing names out of the asset list. leather-io/extension#4113
• Modal routing refactor: overlay and nested route state. leather-io/extension#4325
• UTXO consolidation, the 6-line fix: +6/−10, the best code you delete. leather-io/extension#6085

Frontend: TypeScript · React · Next.js · React Native · Expo · Panda CSS · Tailwind · Radix · Storybook Across the stack: Python · FastAPI · Node.js · Cloudflare Workers · Supabase · CI/CD AI: LLM observability · Langfuse · agent-assisted development Web3: Bitcoin · Stacks · sBTC · Solana · Sui · EVM · viem/wagmi · MetaMask · WalletConnect Tooling: Playwright · Cypress · Maestro · Vitest · TDD

Newcode · Trust Machines · Qredo · Kraken · Cryptowatch · Xapo · Bank of America · Fidelity

GitHub · X · LinkedIn · hello@petewatters.ie · PGP