Skip to content

AI & LLM

Leo

Built an AI Transcription & Research Platform from Scratch

Role
Sole developer
Timeline
Architecture to handover
Team
Solo, alongside founding team
Live link
www.tryleo.ai
4
subscription tiers
Solo
architecture, APIs, frontend, deployment
Used by
Cambridge, Oxford, Yale, Stanford researchers

The problem

Historians and archivists work with handwritten manuscripts standard OCR cannot read, and existing tools require manually transcribing dozens of pages before producing usable output. Leo needed a platform where researchers upload documents, get accurate transcriptions immediately, then organize, search, annotate, and share an entire archive.

My approach

Architecture & data model

Independently designed the application architecture and PostgreSQL schema on Supabase — documents, transcriptions, collections, folders, metadata, per-user credit balances. All backend APIs in Nest.js/TypeScript.

Document pipeline

Upload and processing flow carrying document images through transcription and back into structured, editable text, output preserved alongside the source image for verification. Tuned a multi-model routing layer across transcription providers.

Credits & subscriptions

Tiered plans with differing storage and monthly credit allowances plus purchasable non-expiring credits — credit deduction, monthly resets, graceful downgrade behavior.

Organization, search & export

Custom folders, full-text search across transcriptions and notes, metadata filtering, export to multiple formats.

Sharing

Secure public share links to distribute documents without an account, with recipients able to copy shared documents into their own collections.

System shape

  1. Frontend

    React, Next.js, TypeScript, Tailwind CSS

  2. Backend

    Nest.js, Node.js

  3. Data

    PostgreSQL, Supabase

  4. Infra

    Vercel, Railway

  5. AI

    AI Integration

Stack

Frontend

  • React
  • Next.js
  • TypeScript
  • Tailwind CSS

Backend

  • Nest.js
  • Node.js

Data

  • PostgreSQL
  • Supabase

Infra

  • Vercel
  • Railway

AI

  • AI Integration

Result

A live production platform — built solo and delivered complete — used by professional historians, archivists, and graduate researchers at universities including Cambridge, Oxford, Yale, and Stanford, running a four-tier subscription model with credit-based metering.

Next projectConnect Clean