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Dan Johnson
Product Engineer & Systems Architect

Dan Johnson

I design and build complex, high-reliability software systems, AI-enabled products, and performance-critical applications with a focus on long-term architecture, security, and real-world usability.

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Selected Work

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Sole engineer; AI agents under a governed ticket process

Accrulith — An Engine That Acknowledges Nothing It Has Not Committed

An engine for idle games whose real subject is the oldest problem in payments and webhooks: a request that arrives twice must take effect once, even if the server crashes in between. Ack-after-commit persistence, two-phase idempotency, a compiler-enforced pure core, and a signed tag behind every sprint.

deterministic-coreserver-authoritativeidempotencygosystems-architectureai-assisted-engineering

Senior PM / Full-Stack Engineer

Austin Eischeid — Authority Platform & Editorial System

Design and development of a digital authority platform for a planting designer working at the highest level of landscape architecture.

product-engineeringeditorial-systemsperformanceseoaccessibility

What I Do

Product Engineering

I design and build complete products — from concept to production — with a focus on usability, performance, and maintainability.

System Architecture

I design scalable, maintainable architectures that support real-world product growth and operational complexity.

AI & Automation

I build AI-powered tools and automation systems that turn complex workflows into reliable, repeatable processes.

Performance & Scalability

I optimize systems for speed, efficiency, and the ability to scale without rewriting from scratch.

Security & Reliability

I build systems that are safe, predictable, and resilient — not just functional.

Designer & Stakeholder Collaboration

I work closely with designers and stakeholders to translate ideas into real, working software.

How I Build

Architecture-first thinking. Test-driven development. AI-augmented workflow. Every system I build is designed for long-term reliability, not just launch day.

How I approach engineering

Writing

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architecture

Four Packages That Are Not Allowed to Know What Time It Is

A rule you have to remember is a wish; a rule that fails CI is a property. How Accrulith keeps clocks, floats and chance out of the code that computes balances, why anything that prices or scores needs the same discipline, and the check that turned out to be watching the wrong files.

· 12 min read

ai

How I Let an AI Write Code I Will Ship

The right unit of trust for a coding agent is the smallest action you cannot take back. How ForgeGate lets an agent write most of the code while a program checks its scope, two reviewers must cite evidence, and a human reads every diff before anything is committed — and what it still cannot enforce.

· 12 min read

Work With Me

I take on a limited number of serious engineering projects. If you are building something that needs strong architecture, thoughtful AI integration, or careful technical execution, I would like to hear about it.

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