Project · Coded product

FastPay

A money-coaching web app that makes mortgages clear, and shows people what happens when they pay a loan down faster. This is where I moved from agent design into writing and deploying real coded logic.

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FastPay
Interactive tools for a money-coaching service

Coding proof 2025 Deployed & live Domain · mortgages

What it is

A web app that makes a hard topic, mortgages, clear, and shows people the outcome of paying a loan down faster.

This is where I moved from agent design into writing and deploying real coded logic.

The problem

Mortgages are complex and hard to understand. A coaching service in this space has to demonstrate its value and give visual proof of the result, and that is difficult to do with words alone. It needs working numbers a person can trust.

What I built

  • A multi-step calculator with real formulas and logic that models the numbers. Real formulas doing the work behind the interface.
  • Interactive visual help that turns those estimates into something easy to read.
  • An explainer article that walks a reader through estimated and demonstrated outcomes.
  • Lead capture and booking behind it, so an interested reader becomes a booked call while the follow-up happens on its own.

How it works

An interactive front end that does the hard maths, with capture and booking wired in behind it.

CalculatorMulti-step formulas and logic, built by hand with Claude.
VercelHosts and deploys the front end.
SupabaseStores each lead on submission.
ResendSends a transactional confirmation email.
CalendlyRoutes the person to a booking to close the loop.

The hard part, and the lesson

The calculator was the difficult piece. Multi-step formulas and financial logic are the kind of work that normally needs a developer, and getting them right matters when someone is making a decision about their home loan. Building it with Claude let me ship a working, accurate tool in a domain most people find impenetrable.

LessonAI does not remove the need to understand the problem. It removes the barrier to building once you do. My job was to understand the maths and the customer; the tooling let me turn that into something live.