John Simpson

Twenty years in payments and fintech, serving in positions such as Developer Support, Sales Engineering, and Senior Product Management.

Solutions Engineer · Payments & Fintech
John Simpson
Presales 150+ demos and proofs of concept, $12M+ team revenue
Product Semi-integrated EMV, $5M to $40M ARR
Portfolio Four products, 60% of company revenue
Available now · Full-time · Remote, US Sales Engineer, Solutions Engineer, Solutions Architect, Senior Solutions Engineer, and Solutions Consultant positions.
What I Build

Customized demonstrations for the sales cycle

As a sales engineer, I build interactive demonstrations tailored to the prospect in front of me. Each one is assembled from public API documentation and walks the integration path for their scenario.

The purpose is to make the integration lift visible rather than described, so the technical evaluation moves forward on evidence.

Portfolio

Interactive demos

Below you will find interactive demos that I have built using AI coding tools. Each demo is accompanied by a description. Click the Open demo button to view it in your web browser. No setup or download is required. I will continue adding new demos to this section, so feel free to bookmark this page and check back.

Interchange · Visa / Mastercard
InterchangeIQ

Six tools for interchange fee optimization: transaction validation, downgrade simulation, routing comparison, CEDP readiness checking, rate lookup, and agentic commerce risk analysis.

Open demo →
ACH / RTP / FedNow
US Payment Rails Explorer

Bank-based payment rails across gaming, prediction market, and crypto verticals, with an animated transaction lifecycle.

Open demo →
Checkout · Identity · Fraud
Checkout & Fraud Explorer

Three simulations showing how checkout, identity verification, and fraud screening fit together in a single commerce flow.

Open demo →
Agentic Commerce
Agent Trust Dashboard

Monitoring and intervention for autonomous purchasing agents: live activity feed, decision audit trail, anomaly detection, per-agent kill switches.

Open demo →
Monte Carlo · Optimization
FundraiseAI

Portfolio-level optimization with Monte Carlo scenario simulation for capital campaign planning.

Open demo →
Command Line Utilities

I have built smaller utilities that require local installation from GitHub and command line interaction. These can be viewed on my GitHub page at github.com/jesimpsonjr-prodmgmt.

Connect with Me

LinkedIn GitHub