Full-Stack Developer for Financial Data Platform - Part-time - Worldwide (Some CET overlap required)

Role

Full-stack developer to build a financial data platform. The main feature will be an AI-powered

financial chatbot. Users will be able to ask questions like, “What are Amazon’s cloud revenues

for each of the last 5 years?” and the answer will show a chart and text. In addition to the

chatbot, developer will build dashboards and pages showing how markets are trading through

charts, tables, heatmaps, screeners, watchlists, etc. Work spans the full stack: backend (data

pipelines, caching, database optimization), AI (LLM flows, RAG, prompt tuning), and frontend

(js charting libraries and responsive UI). An early version of the watchlist, which will be one

component of the final product, is live at stock-miner.com.

Chatbot Feature - What you’ll work on

Build data pipelines: ingest financial data from APIs → parse and transform into structured

formats → store in PostgreSQL. Data includes structured data (financials, prices, earnings,

analyst ratings) and unstructured documents (SEC filings, earnings call transcripts, investor

presentations, etc.).

Build LLM pipelines: documents → Embeddings (OpenAI) → vector retrieval via pgvector

(RAG) → prompt construction → answer generation → validation (catch wrong numbers, dates,

hallucinations).

Prompt engineering: tune prompts to improve accuracy, reduce hallucinations, and handle edge

cases.

Charts: build visualizations for chat responses using Highcharts or similar.

Scale coverage: extend to thousands of US stocks.

Why charts matter

A major differentiator is how we present data visually within the chatbot. We’ll post charts on X

and other platforms to grow our audience. If you’ve made data look beautiful with JS charting

libraries, that’s a big plus.

Collaboration

Developer will work directly with the founder, who handles product direction and domain

expertise (finance background, 10+ years investing/trading), while dev handles the technical

execution.

Current tech stack

Frontend: React, Next.js (App Router), TypeScript, Tailwind CSS

Backend: Next.js Server Actions, API Routes

Database: Supabase (PostgreSQL + pgvector for embeddings)

AI/LLM: OpenAI API (incl. embeddings), prompt engineering, RAG patterns

Charts: Highcharts, TradingView Lightweight Charts, HTML5 Canvas

Data APIs: Financial Market API (FMP, Polygon.io, etc.), SEC EDGAR

Required

Experience with React and TypeScript

Experience with Next.js

Experience with PostgreSQL

Understanding of REST APIs and data fetching patterns

Experience with OpenAI API or similar LLM integrations

Familiarity with vector databases and RAG patterns

Knowledge of real-time data patterns (WebSockets, polling)

Clean code practices and attention to detail

Good English and communication skills

Nice to have

Experience with financial data or fintech applications

Experience with JS charting libraries (Highcharts, Chart.js, D3, Recharts, TradingView

Lightweight Charts, etc.)Experience with JS charting libraries (Highcharts, Chart.js, D3, Recharts, TradingView

Lightweight Charts, etc.)