Full-Stack AI Developer (MVP, Langgraph) - Fulltime - NA/LATAM/EU

Arc Full-time
yesterday

Role details

Contract type
Permanent contract
Employment type
Full-time (> 32 hours)
Working hours
Regular working hours
Languages
English
Experience level
Senior

Job location

Remote

Tech stack

API
Artificial Intelligence
Amazon Web Services (AWS)
Amazon Web Services (AWS)
Amazon Web Services (AWS)
Data Validation
Data Mining
Document Management Systems
Identity and Access Management
Python
PostgreSQL
Query Optimization
Ui Patterns
Next.js
Software Safety
Service Layer
TypeScript
Web Applications
Tailwind
React
Large Language Models
Prompt Engineering
Backend
GIT
FastAPI
Stripe
Front End Software Development
Virtual Agents
Api Design

Job description

You will be the sole engineer building Lucro's MVP. This is a full-stack role that spans AI agent pipeline design, API development, and a clean client-facing web application. The product is well-specified - the architecture, tech stack, and core logic have been designed in detail. Your job is to bring it to production. You are comfortable owning the entire s, LangGraph-based stateful agent workflow for QRE classification and Form 6765 preparation Pydantic AI structured data extraction from payroll records, invoices, and project docs NeMo Guardrails integration for PII detection, input validation, and output safety Claude 3.5 Sonnet (Anthropic API) for classification reasoning and narrative generation

Backend & API FastAPI service layer connecting the agent pipeline to the frontend Supabase / PostgreSQL schema for clients, engagements, QRE records, and documents Stripe integration for invoice generation and payment processing Secure document storage and access control

Frontend Next.js + Tailwind CSS client portal: data submission, status tracking, package download Clean, professional UI appropriate for a B2B fintech product Async-first design - fully digital, no in-person touchpoints

Infrastructure AWS deployment (EC2 t3.medium for MVP; ECS is out of scope) Environment management, secrets handling, and basic monitoring 12-week delivery timeline from signed engagement to production-ready MVP tack, making pragmatic decisions under a tight timeline, and shipping something real.

Requirements

Non-negotiable

  • Python (advanced): FastAPI, async patterns, data modelling
  • LangGraph: stateful agent design, multi-step pipelines, checkpointing
  • Pydantic / Pydantic AI: schema design, structured LLM output extraction
  • LLM API integration: Anthropic Claude API or equivalent; prompt engineering
  • Next.js + React: full-stack TypeScript, server components, API routes
  • Tailwind CSS: component design, responsive layout, B2B UI patterns
  • PostgreSQL: schema design, query optimisation, Supabase or equivalent
  • AWS: EC2 deployment, IAM, S3, environment configuration
  • Stripe: invoicing, payment intents, webhook handling
  • Git: clean commit history, solo project discipline

Nice to Have

  • NeMo Guardrails or equivalent AI safety framework
  • Experience with MCP (Model Context Protocol) connectors
  • Prior solo product builds shipped to production
  • Fintech, taxtech, or document automation background
  • Familiarity with IRS Form 6765 or R&D credit workflows (not required)

You Are

  • Comfortable owning an entire stack without a team around you
  • A pragmatic builder - you ship clean, not perfect
  • Proactive about ambiguity - you ask the right questions, then move
  • Proud of readable, maintainable code under a tight deadline

Benefits & conditions

  • Clearly scoped MVP with a detailed architecture and tech stack already defined
  • Direct working relationship with the founder - fast decisions, no layers
  • Competitive contract rate, negotiated based on experience
  • Equity consideration for the right long-term fit
  • Remote and async-first working environment
  • A real product in a large, underpenetrated market - not a prototype

About the company

Lucro is an AI-powered R&D tax credit documentation service for US-based, VC-backed technology startups. We identify qualifying R&D expenditures, calculate the federal credit under IRS Section 41, and deliver a complete, audit-ready Form 6765 package to the client in under one week - replacing a process that traditionally takes 8-12 weeks with a human consultant. We are pre-launch and looking for a single, highly capable engineer to build the full product from the ground up.

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