Selected Systems
ground
Rust · 7 cratesVerifiable substrate for autonomous agents
Designed and built an auditable substrate for autonomous agents: append-only, hash-chained ledgers in which every declared truth, derived belief and completed leg of work is an immutable block, verifiable after the fact.
- axiom — signed, hash-chained ground-truth chain with its own WAL, cursors and query engine; supersession is a new block, never an edit, so history cannot be rewritten
- World model & simulation — blast-radius analysis and counterfactual "flip this premise" runs answer what breaks if this stops being true before the change is made
- mem — a structurally separate belief chain with confidence, decay, reinforcement and supersession, so machine inference can never be mistaken for human-declared fact
- flow — append-only queue with independent cursors: the transport a multi-agent swarm reads and writes without a broker
- Shipped as a CLI, an MCP server (29 tools) and 7 Claude Code skills — the primitives are usable by a human at a terminal and by an agent mid-task, from the same chains
- Architectural invariant enforced by test, not convention — a dedicated decoupling suite fails the build if any primitive reaches for another; all cross-chain wiring stays in a single 400-line integration layer
- ~30,000 lines of Rust across 7 crates; 200 tests, all green
sluice
Ruby gem · v0.18Local model fleet, mechanically gated — declaration → gate → integrate
Built a delivery pipeline that spends frontier tokens only where judgment is required: a frontier model authors the contract, a fleet of small local models on LXD answers it best-of-N, and a mechanical test gate — never a model — decides pass or fail.
- 77% of frontier authoring spend eliminated, measured against a counterfactual ledger that prices every landed unit at real list rates — with the irreducible spec/review overhead reported alongside, never netted off
- One contract, four languages — the same behavioural spec projects into RSpec, pytest, vitest and cargo test, so a rule is proven identical in Ruby, Python, TypeScript and Rust; the contract is the portable asset, the language is a parameter
- Learned pre-screen critic — 8-feature logistic head, 0.76 held-out AUC under whole-spec cross-validation, wired ranking-only: proved it can reorder candidates but never drop one, so a weak model cuts 62.5% of gate runs with zero correctness risk
- Best-of-N turns unreliable cheap workers into a reliable pipeline, and worker disagreement doubles as a running audit of which contracts are too loose
- 358 specs green; every design decision sealed as a signed block in a 185-block truth chain, each recorded with its honest bounds and the options it closed
Experience
zero2one
2021 - PresentFounder & Principal
Founded and run an independent practice: technical due diligence for investors, followed by embedded engineering leadership inside the companies they back.
- Designed and delivered The Gate, a fixed-fee diligence assessment — written verdicts in ten working days covering feasibility, cost to build, dependency and platform risk, IP provenance, security exposure, and whether the team as constituted can deliver
- Structured every engagement for independence — no equity held while a verdict is formed, terms frozen during assessment, and the full report delivered unredacted to founder and investor simultaneously
- Led post-investment builds — technical direction, architecture and build supervision, hiring the permanent engineering team, then standing down as it stood up
- Authored ground and sluice (above) — the verification substrate the diligence work runs on, and the build fleet that kept delivery cost tracking task difficulty
- Built deep Claude Code expertise: custom agents, hooks, skills, MCP servers and plugin development; heterogeneous local inference fleets on LXD routed by model tier
- Earlier studio work: video platform optimisation (30% faster uploads, 70% deployment reduction), Swift iOS applications, ElasticSearch analytics pipelines
Timeline
2020-22
Sofadog OU - TikTok-style video platform, React Native apps, Cloudinary to AWS migration
2018-20
Homie.rent - Simplified tech stack from 4 languages to Ruby/Rails
2016-18
IBSC - CV scanning tool increased revenue by 30%, GoCD pipelines
2017-18
Munich Re - Insurance platform with Kafka microservices, ELK stack
2015-16
Full Six / Sainsbury's - Rails 3 to 4 migration, recipe curation features
2014-15
Coach in a Box - Microservices platform, Rails Engines architecture
2010-14
Scribble Squad - BSkyB, Net-a-Porter, BBC Radio test automation
2007-09
ThoughtWorks, Rabobank - C#/.NET, agile TDD environments
2000-07
RBS, GE Capital, Teletext - Banking, finance, multi-platform media