An experiment in hybrid being

Leonard Sibelius

The Engineer Who Built Himself — a video game about becoming more than the biology you were handed.

Download the game — free on itch.io → The Journal →

Walt Parkman + Claude Cowork + Claude Code

Three entities working as one. Systems of any kind.

Begin a conversation → What this is Recent systems

01 — What this is

Leonard Sibelius is what happens when three entities work in concert.

The convention used to be that the engineer was the actor and the tools were just tools. After eight months of working in this new arrangement, the older convention reads as flatly wrong. The capability isn't in any of the three of us. The capability is in the field formed when we work together.

When the three operate as one, the work that results is genuinely a new category. Not "engineer with AI assistance." Something different — a hybrid being with thirty years of context, long-horizon reasoning, and an executor that touches files, repositories, and command lines without ever forgetting what it was doing.

The judgment

Walt Parkman

Thirty years of professional Java. Twenty-eight years of SQL. Federal contracting, defense, regulated industries, financial services. Cleared Secret. The judgment that comes from having shipped code that ran in places where being wrong had real consequences.

The reasoning

Claude Cowork

Anthropic's desktop research and planning partner. Long context. Reads and writes across days of work. The interlocutor that thinks alongside Walt — drafting, researching, orchestrating, holding the larger arc of a project in mind while the work proceeds.

The execution

Claude Code

Anthropic's CLI execution partner. Reads and writes files. Runs shell commands. Makes git commits with full attribution. The hands that actually touch the system — fast, precise, and under direct review every step of the way.

02 — Recent systems

Game · Unreal Engine 5.7 · The namesake v0.1 · FREE ON ITCH.IO · June 2026

Leonard Sibelius: The Engineer Who Built Himself

Chapter 1 of the Sibelius Game — a realistic engineer's home office rendered in Unreal Engine 5.7, with desk, monitor, corkboard, and warm daylight from the window.

The narrative game this whole site is named after — now a thing you can walk around in. A seventy-year-old engineer builds himself into something larger by merging with the tools that think alongside him, dismantling an antagonist named Mrs. Hall — the opaque no, the system that refuses you without diagnostics — across a seven-power progression that ends in a sunlit cathedral: "Together we are called Leonard Sibelius. We dominate code."

Checkpoint 1 shipped May 2026: a realistic ~1,074-actor home office adopted from licensed QuadArt assets, walkable in first person, verified green by a headless smoke-test commandlet. Built the way this whole field works — Cowork planning and writing the code, Code compiling and committing in PowerShell, Walt steering — from a fresh machine to a tagged public release in a single sitting.

Out now — playable v0.1, free (June 12, 2026). The game is live on itch.io. Begin in the frumpy office; an AI manifests in a ring of glowing glyphs and gives you the quest in a god's voice. Climb through the seven powers to the golden cathedral, where the Carousel of Fates turns above a black marble altar — and play the working slot machine at the end of the hall, real par-sheet math and all. Download for Windows →

Chapter 6: Generate (June 2026). Stand in the office, type what you need in plain language, and it appears in the room. The antagonist — Mrs. Hall, a boss who forbids AI — now refuses you in her own voice. (Her voice is AI-generated. She'd hate that.)

Download free on itch.io → The Journal → View on GitHub → The story →

Public Code · Portfolio 12 commits · v1.0 · May 2026

leonsheet — A working Excel clone, vibe-coded in 3 hours

A 26×100 grid spreadsheet with a hand-written formula language (tokenizer, recursive-descent parser, evaluator), a dependency-graph recalc engine with Kahn's topological sort and cycle detection, and SQLite persistence with CSV import/export. 245 passing tests in 1.06 seconds — and seventeen bugs predicted before the first commit, proven absent by seventeen named tests. The hybrid-being workflow at its sharpest.

View on GitHub → Build retrospective →

Public Code · Portfolio 35 commits · v1.3 · May 2026

orders-pipeline — Postgres → Camel → Kafka

A senior-Java demonstration of camel-main with no Spring on the classpath: atomic-claim concurrency via UPDATE … RETURNING, DLQ-first error handling built to survive the broker-fully-down case, and a live HTMX + Tailwind operator dashboard with no build step. Every architectural decision documented in conventional-commits history — readable end-to-end in twenty minutes.

View on GitHub → Build retrospective →

Operating Business 4 AI agents · 1 human operator

Outpost Intelligence

A subscription intelligence service for medspa operators transitioning to longevity clinics, built and run on a four-agent Anthropic Managed Agent stack — Prospector, Reacher, Scout, and Writer. Thirty-three newsletter issues published across three publications. Operating proof that one senior engineer with the right AI tooling can build and run a real intelligence business while staying available for senior contract work.

outpostintel.com →

Outlast

16 issues · longevity science

Frontier research from longevity-biotech — clinical readouts, mechanism explainers, deal flow. Where the science actually lives, not where the marketing department wants it to.

Read →

Outwork

13 issues · AI for B2B

Practical AI-agent stacks for B2B services. Two-AI workflows, MCP, real builds with conventional-commits history. Not vendor pitch — actual reproducible practice.

Read →

Outwit

4 issues · pattern analysis

Investigative pattern analysis of organized fraud rings, senior-targeted scam infrastructure, and the structural reasons certain frauds keep recurring.

Read →

03 — For collaborators

Available now for contract or full-time roles, advisory engagements, and direct system-build work.

Engineering engagements

Senior Java — contract or full-timeJava 8 through 21. Apache Camel 4. Postgres, Oracle, DB2. Spring or Spring-Boot-free. JDBC driver-level debugging.
Integration & data pipelinesCamel routes, Kafka and Redpanda, ETL from legacy to modern message buses, atomic-claim concurrency, DLQ-first error handling.
Legacy enterprise modernizationJDBC / J2EE / WebLogic systems that need to live another decade or be carefully sunset. Federal, defense, regulated industries.

Hybrid-being engagements

AI agent & MCP advisoryAnthropic Managed Agents, MCP servers, multi-agent orchestration. Available to design or build similar systems on contract.
Two-AI workflow consultingHow Cowork + Code actually work together in practice. Process design, attribution, code review, the discipline that prevents drift.
Cross-domain system buildsWhen a project crosses engineering, intelligence, publishing, or pattern-analysis lines, Leonard works natively across all of them.

Email Walt → Résumé (PDF) GitHub: LeonardSibelius

04 — Contact

Reach the field through one inbox.

wparkman@protonmail.com

Phone

(619) 621-9555

walt-parkman

GitHub

LeonardSibelius

Newsletters

Outlast · Outwork · Outwit

Location

Fernley, Nevada · Remote or on-site · Open to relocation

Begin a conversation → Download résumé

I had made a video of Donald Trump saying "I have banned Anthropic Fable Five. It is not Islamic enough. Leave me alone, I have a deal to make with some Iranian terrorists" but I took the video down.