AI Applications Engineer - Full-Stack AI/LLM Platform

Bigbear.ai; McLean (VA); Hybrid; USD 120,000 - 180,000; Full time

Job summary

BigBear.ai seeks an AI Applications Engineer to build end-to-end AI applications and a config-driven decision-support platform that blends LLM-powered chat, structured data, and dashboards to support operational readiness and logistics workflows. You will own features across backend APIs, database, and a modern React UI while migrating a Dash/Flask app.

You will design and implement LLM/RAG pipelines with LangChain or LangChain4J, connect to external data sources, vector stores, Redis, and

Qualifications

• 3+ years of full-stack development with Python and React/TypeScript.
• Ability to obtain and maintain a security clearance.
• Hands-on LLM/RAG experience with LangChain or LangChain4J.
• Experience building and consuming REST APIs (FastAPI or similar).
• Solid PostgreSQL skills: schema design, SQL, migrations (pgvector a plus).
• Comfortable with Docker, local dev environments, and deployment workflows.
• Strong debugging, testing, and code review habits.
• Ability to work independently across backend, frontend, database, and AI layers.
• Proficient with using AI coding assistants as part of daily workflow.

Responsibilities

• Build and maintain full-stack features: FastAPI services, PostgreSQL schema/migrations, and React/TypeScript UI in an Nx monorepo.
• Design, implement, and maintain LLM/RAG pipelines using LangChain or LangChain4J.
• Integrate LLM providers, document ingestion, semantic search, and chat/report features.
• Work with vector stores (PostgreSQL pgvector, Weaviate), Redis, and Keycloak auth; implement RBAC.
• Connect to external systems via MCP, REST/PostgREST, and related data adapters.
• Write and maintain tests (pytest, Vitest) and participate in CI/CD (Docker, GitHub Actions).
• Debug production issues, improve reliability/performance, and keep dependencies secure.
• Use AI-assisted development tools effectively and ship production-quality changes.

Skills

Python

React/TypeScript

LLM/RAG

REST APIs

SQL

Debugging

Testing

CI/CD

Independent work

Tools

FastAPI

Docker

GitHub Actions

PostgreSQL

pgvector

LangChain

Nx monorepo

Redis

Keycloak

Job description

BigBear.ai seeks an AI Applications Engineer to build end-to-end AI applications and a config-driven decision-support platform that blends LLM-powered chat, structured data, and dashboards to support operational readiness and logistics workflows. You will own features across backend APIs, database, and a modern React UI while migrating a Dash/Flask app.

You will design and implement LLM/RAG pipelines with LangChain or LangChain4J, connect to external data sources, vector stores, Redis, and