Senior Full-Stack Engineer

Employment Type: Full time, independent contractor (Short Term Contract)
Work Model: Remote
Work Hours: US work hours

Role Overview

We are seeking a Senior Full-Stack Engineer to build a production-ready application that uses LLM vision models to extract structured data from images and transform it into validated outputs for healthcare billing workflows.

This role is backend-dominant but fully full-stack. You will implement a multi-stage data extraction and validation pipeline in Python, integrate it with an existing React frontend, and deploy the system on Google Cloud Platform.

The project has already been extensively scoped. Over 130+ pages of architectural documentation, technical decision documents, and validation rules are available. Your primary focus will be implementation, integration, testing, and production hardening, rather than early product discovery.

You will work directly with the founder to transform the detailed specification into a reliable production application.

About the Product

The platform extracts billing data from hospital census sheets used by physicians.

Doctors photograph their patient lists, and the system:

Validates image quality on-device
Extracts structured data using LLM vision models
Runs a multi-stage backend validation pipeline
Allows physicians to review extracted data
Exports validated records to billing software

The goal is to eliminate hours of manual transcription work physicians perform each week.

Core Architecture

Mobile App: React + Capacitor
Backend: Python + FastAPI
Infrastructure: Google Cloud Run
Database: PostgreSQL or Firestore
LLM Vision: Claude (primary) with backup provider
CI/CD: GitHub Actions
Compliance: PHIPA healthcare privacy requirements with Canadian data residency

What You’ll Build

This project centers around a data extraction and validation pipeline, not a traditional CRUD application.

Data Extraction Pipeline

Integrate LLM vision models to extract structured data from uploaded images
Implement failover logic between primary and backup model providers
Normalize and parse model outputs into structured backend objects

Validation & Business Logic

Build a multi-step validation system including:

Billing code normalization and database validation
Diagnostic code resolution
Date format disambiguation
Physician lookup and reference dataset matching
Data confidence scoring

Extracted data must be categorized into:

High-confidence
Review-required
Invalid

before export.

Backend Infrastructure

Build backend APIs using Python and FastAPI
Design secure data pipelines and database schemas
Implement validation and processing workflows
Configure CI/CD pipelines and cloud infrastructure

Frontend Integration

Review and integrate an existing React + Capacitor frontend
Connect backend APIs to the mobile UI
Implement state management, validation states, and error handling
Ensure mobile-grade reliability and resilience

Export Pipeline

Generate spreadsheet outputs compatible with billing software
Implement multi-layer validation gates before export
Prevent invalid data submissions through deterministic checks

Key Responsibilities

Implement a production-ready full-stack system from detailed specifications
Build backend services using Python and FastAPI
Integrate and validate a React + Capacitor frontend
Deploy and manage infrastructure on Google Cloud Platform
Implement CI/CD pipelines and secure DevOps practices
Build reliable data extraction and validation pipelines
Integrate LLM APIs with redundancy and failover logic
Write automated tests and maintain high code quality
Ensure system monitoring, reliability, and error handling
Proactively improve engineering solutions where needed

Required Qualifications

Technical Experience

Strong full-stack engineering experience
Deep expertise with Python backend development
Experience building production systems using FastAPI or similar frameworks
Experience working with React applications
Familiarity with cloud infrastructure (GCP preferred)
Experience building data processing pipelines or validation systems
Experience integrating third-party APIs
Strong debugging, troubleshooting, and problem-solving ability

Working Style

Comfortable working independently from detailed technical specifications
Strong written communication and documentation skills
Ability to own complex systems end-to-end

Preferred Qualifications

Experience working with LLM APIs or AI-driven applications
Experience with OCR or image processing workflows
Familiarity with PostgreSQL or vector databases
Experience with DevOps workflows and CI/CD
Experience building mobile-friendly web applications
Experience working with healthcare or regulated data environments

Ideal Candidate Profile

The ideal engineer for this role:

Works independently without needing heavy management
Is comfortable reading and implementing detailed technical documentation
Has strong problem-solving and debugging ability
Communicates clearly and flags issues early
Enjoys owning systems end-to-end
Thrives in implementation-focused engineering work

Engineers who enjoy building complex systems from detailed specifications will excel in this role.

Senior Full Stack Engineer (Backend Focus) - 18371