MRJ.
Marvin R. Johnson

Nuclear reactors
to neural
networks.

I have spent a career mastering progressively complex, high-stakes systems: nuclear propulsion, then global payments, now generative AI and agentic systems architecture.

Get in touch See the lab →
Marvin R. Johnson
#1
Rated officer
U.S. Navy nuclear submarine service.
120
Countries
iKobo's prepaid remittance reach.
20
Years shipping
Nuclear, payments, now AI.
01 · COVALENCY

One ecosystem, four bonds.

Peppi Labs is the studio: rapid prototyping, full-stack builds and AI architecture, on a two-week sprint that ends in a ship-or-pass decision. The same team then turned that method on itself. Peppi.ai is a personal AI companion that works entirely over SMS, no app. AskPeppi gives a local business an assistant that answers customers around the clock. PeppiPay is spending infrastructure for AI agents, with real-time policy autonomous enforcement and a human in the loop when needed.

Karl (Peppi)
Karl (Peppi)
SMS AI Companion
Hey Karl! Can you check my schedule for tomorrow morning?
Of course! Tomorrow you have Project Sync at 9:00 AM and Team Meeting at 11:00 AM.
ping me at 8:30 AM i may be up late.
Reminder set for 8:30 AM tomorrow 🌞. Get some rest!
can "Add Joseph Doe" to the Team meeting. He should be there for this one.
Done! Added Joseph Doe to Team Meeting at 11:00 AM.
Text message
PEPPI.AI

Seamless Scheduling & Memory

Your always-on, SMS-based AI companion for effortless scheduling, reminders, and context recall. Interact naturally to organize your day without switching apps.

Smart Scheduling via Text
Intelligent Contextual Memory
Proactive Reminders & Pings
Team Calendar Integration
Zero App Overhead
Effortless Context Management
Meet Peppi at Peppi.ai ↗ Try Live Demo
02 · THE LAB

Nine things I built to learn.

These are my personal projects, built, funded and operated by me outside client work. Peppi Labs engagements are separate.

01 Personalized fiction POVella AI-powered personalized fiction. You're not reading the story. You are the story. Web App Store povella.net ↗
02 Marketplace NYC Plug The connective tissue for New York: find what you need, from whoever has it. Web App Store Google Play nycplug.net ↗
03 Decision science Deliberata A thinking partner for the choices that matter, one good question at a time. Web deliberata.net ↗
04 Generative art QR Code Art Scannable QR codes rendered as generative artwork rather than black squares. Web qrcodeart.net ↗
05 Community We Black Chat A conversation space built for and by the Black community. Web weblackchat.com ↗
06 Fishing forecast Baitful Fishing intelligence: conditions, forecast, spots and gear, in one place. Web App Store Google Play baitful.com ↗
07 Music Mix Mob Collaborative mixing and music discovery for people who make playlists like records. Web Google Play mymixmob.com ↗
08 Email AI KopyKat Aggregate email from any source, chat with your data, get instant inbox insight. Web kopykat.ai ↗
09 Novel Beneath the Surface A literary thriller written with AI as a creative collaborator. Amazon ↗
Where I've served and shipped
U.S. Navy
Mastercard
Western Union
Peppi Labs
Each mark sits unmodified on a white chip. They denote employment history only. Check each brand's trademark guidelines before publishing.
03 · RESUME

Where a rollback wasn't an option.

Nuclear reactor operations and regulated money movement teach the same discipline: you cannot ship optimism. Every assumption has a failure mode, someone has to own it, and the person who owns it writes it down. AI collapses the time between an idea and a working system, but speed without governance is just a faster way to be wrong. The controls carry over. Oversight, auditability, a human in the loop at the decisions that matter.

1
U.S. Navy
Nuclear submarine officer. Rated #1 officer on board.
2
iKobo
Co-founder & CEO. Send-to-card remittance, acquired by M2 Payment Solutions.
3
Mastercard
Global Director, Product Development. Debit and prepaid at global scale.
4
Western Union
Head of US Ecosystem Product. Cross-border digital banking.
5
Peppi Labs
Founder & CEO. Building products at AI speed.
04 · ADVISORY

Startup advisory & mentorship.

Founders I work with directly on product, payments architecture and the discipline of getting to a decision.

05 · FOUNDATIONS

It started with materials science.

As an undergraduate at the University of Florida I published peer-reviewed research in advanced materials science, fully funded by Pratt & Whitney to pioneer next-generation aerospace composites. Systems-level thinking about how things fail has been the through-line ever since.

University of Florida
B.S. Materials Science & Engineering
University of Florida
Georgia State University
MBA, Decision Sciences
Georgia State University
Published research
High-Temperature Structural Silicides
Published research on MoSi₂/SiC composites for aerospace applications through mechanical alloying and carbothermal reduction synthesis.
University of Florida, Department of Materials Science & Engineering. Sponsored by Pratt & Whitney.
In-Situ Composite Reinforcement
Research on novel processing methodologies for enhanced fracture toughness and thermal shock resistance in refractory intermetallics.
University of Florida, Department of Materials Science & Engineering. Sponsored by Pratt & Whitney.
06 · WRITING

Writing.

Latest 10 August 2026

From MVP to PVP

A Personally Viable Product

From MVP to PVP: Building Software for OneFor most of my career in technology, building software required answering a fundamental question:Is the market big enough?We talked about TAM, SAM and SOM. We...

Read the post →
All writing →
Let's connect

Speaking, advisory, or building something at the frontier.

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