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NumisBook

A coin collection management SaaS that helps collectors visualise the fundamental aspects of their coins, organise them and monitor price statistics. The collector can also interact with an AI-assisted chatbot to manage their collection and obtain information from it.

How I built it

Used Claude Code as a virtual cross-functional development team, creating specialised skill workflows for architecture, database design, UI design, testing, governance and project management. Integrated MCP tools including Figma, Neon and Playwright to connect product design, data migration and E2E testing.

01 — Problem

Collectors lack a single source of truth

Coin collectors often manage inventory, purchase documentation and collection information across spreadsheets, cloud storage and physical documents, making the collection difficult to manage and analyse.

02 — Product

One place for the whole collection

A cloud-based SaaS platform that centralises coin inventory, images and documentation while providing collection analytics and an AI assistant for natural-language exploration.

03 — Key decisions

Cloud-first, with AI grounded in the data

Cloud-first architecture · Structured collection data model · Integrated documentation & media · AI grounded in collection data

04 — Outcome

A production SaaS MVP

Production SaaS MVP · Collection management · Analytics · AI assistant · Extensible data architecture

05 — My contribution

From strategy to end-to-end development

Product strategy · Data architecture · UX/UI · Database & media infrastructure · AI · End-to-end development

Built with

  • Next.js
  • TypeScript
  • PostgreSQL on Neon
  • OpenAI
  • Vercel
  • Cloudflare R2
NumisBook’s window, showing its dashboard: the number of collections and coins and the total paid, above links to the collections and the portfolio and the most recent acquisitions, each with both faces of its coin and its price
NumisBook’s window, showing its dashboard: the number of collections and coins and the total paid, above links to the collections and the portfolio and the most recent acquisitions, each with both faces of its coin and its price

The dashboard

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The dashboard
NumisBook’s window, showing the collections, Spanish Empire and Roman Republic, Imperatorial & Empire, each as a card with a photograph of one of its coins
NumisBook’s window, showing the collections, Spanish Empire and Roman Republic, Imperatorial & Empire, each as a card with a photograph of one of its coins

The collections

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The collections
NumisBook’s window in its dark theme, showing the coins of the Roman Republic, Imperatorial & Empire collection in a table, below a search and filters for metal, category, denomination, mint, grade and year
NumisBook’s window in its dark theme, showing the coins of the Roman Republic, Imperatorial & Empire collection in a table, below a search and filters for metal, category, denomination, mint, grade and year

A collection’s coins

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A collection’s coins
NumisBook’s window in its dark theme, showing a coin’s record: a silver denarius of Brutus with its details, description, catalogue references and provenance, beside its photograph and its invoice
NumisBook’s window in its dark theme, showing a coin’s record: a silver denarius of Brutus with its details, description, catalogue references and provenance, beside its photograph and its invoice

A denarius of Brutus

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A denarius of Brutus
NumisBook’s window in its light theme, showing a coin’s record: a silver tetradrachm of Mark Antony and Cleopatra with its details, description, catalogue references and price, beside its photograph and its invoice
NumisBook’s window in its light theme, showing a coin’s record: a silver tetradrachm of Mark Antony and Cleopatra with its details, description, catalogue references and price, beside its photograph and its invoice

A tetradrachm of Mark Antony and Cleopatra

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A tetradrachm of Mark Antony and Cleopatra
NumisBook’s window in its dark theme, showing the portfolio: the total paid, a chart of the acquisition cost over time, and a bar chart splitting each coin’s cost into hammer price, premium, tax and shipping
NumisBook’s window in its dark theme, showing the portfolio: the total paid, a chart of the acquisition cost over time, and a bar chart splitting each coin’s cost into hammer price, premium, tax and shipping

The portfolio

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The portfolio
NumisBook’s window, showing the settings: the profile’s display name, with its email blacked out, the language, theme and base currency, and a danger zone for deleting the account
NumisBook’s window, showing the settings: the profile’s display name, with its email blacked out, the language, theme and base currency, and a danger zone for deleting the account

The settings

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The settings
A silent screen recording of NumisBook, a minute long. From the sign-in page it enters the demo collection and goes through the dashboard, the collections, the coins of one collection, the record of a tetradrachm of Mark Antony and Cleopatra with its photographs, the portfolio’s charts and the settings, where the theme changes to dark and back. It ends with the assistant answering what it can do.

Video walkthrough

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Video walkthrough
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