Live
Bullion API
Live and historical spot prices for gold, silver, platinum and palladium, with predictable pricing and a developer-first API.
- My work
- Product direction, API design, authentication, billing, provider integrations and operations.
Paul Underwood
I'm a software engineer in the UK. I build and operate small software products, APIs, developer tools and agent workflows.
Most of my recent work is on Bullion API, PostConductor, Satzo and SeedScore. I write about the decisions behind the work in project stories and the Notebook.
Selected projects
All projects
Live
PostConductor
An MCP-native workflow for agents to find ideas, draft posts, schedule them and publish safely across social channels.
- My work
- Product direction, MCP and API contracts, authentication, queueing, billing and delivery workflows.
In development
Satzo
UK crypto CGT estimates with Section 104 pooling, same-day and 30-day matching across Bitcoin, Ethereum and Solana wallets. Screenshot from the staging preview.
- My work
- Product direction, CGT calculation rules, wallet integrations, reporting and operations.
In development
SeedScore
Evidence-led due diligence for UK equity crowdfunding, scoring Crowdcube and Seedrs raises across ten traceable categories. Screenshot from the staging preview.
- My work
- Product direction, research pipeline, scoring rubric, Companies House and news integrations.
Open source
Recent Notebook entries
Browse the NotebookBuilding one portfolio view for all my crypto walletsProjects · 25 SeptEmail verification belongs at the API boundaryAPIS · 02 AugInfrastructure questions belong before the first line of codeAI · 02 AugSEO feedback should become bounded engineering workAI · 02 AugA status page should explain incidents, not just show greenObservability · 29 JulAgent workflows should outlive their modelsAI · 27 JulBuilding PostConductor: Why I Pivoted to MCP-FirstAI · 01 JulStop Blaming the ModelAI · 19 JunHarness EngineeringAI · 18 JunA Modern Quality Pipeline and Testing Strategy for Frontend ProjectsGood Code · 17 Jun