AI-Driven Full-Stack Engineer: LLMs, RAG, React/Node

Fantom Corporation; Chantilly (VA); On-site; USD 120,000 - 170,000; Full time

Job summary

Fantom Corporation in Chantilly, VA is seeking a Full Stack Software Engineer to design scalable web apps, implement AI-powered search, and integrate LLMs.

You will build SPAs with React, develop RESTful APIs with Node.js, and work with Elasticsearch for enterprise search, RAG pipelines, and vector search.

Join a team practicing Lean Agile, DevSecOps, and cloud-native development across AWS/Azure to deliver mission-critical solutions.

Qualifications

• Must be fully cleared with a recent polygraph.
• Experience working in Lean Agile software development environments.
• Experience developing enterprise software applications throughout the full software development lifecycle.
• Experience building AI-powered applications using Large Language Models (LLMs), Retrieval-Augmented Generation (RAG), semantic search, or AI-assisted retrieval systems.
• Experience translating customer requirements into scalable technical designs.

Responsibilities

• Participate in Lean Agile ceremonies, including sprint planning, backlog grooming, daily standups, and retrospectives.
• Collaborate with product owners, engineers, operations, cybersecurity, and testing teams to deliver scalable software solutions.
• Design, develop, test, and maintain full-stack enterprise applications.
• Build modern Single Page Applications (SPAs) using React, HTML5, CSS3, and JavaScript.
• Develop RESTful APIs and backend services using Node.js, Express, or comparable frameworks.
• Design, implement, and optimize enterprise search solutions using Elasticsearch.
• Develop AI-powered search capabilities, including Retrieval-Augmented Generation (RAG) pipelines and semantic search solutions.
• Integrate Large Language Models (LLMs) into enterprise applications to enhance search, knowledge retrieval, and user workflows.
• Design and implement data ingestion pipelines supporting search indexing, document chunking, embeddings, and vector search.
• Develop detailed technical designs, interface specifications, and supporting documentation.
• Collaborate with stakeholders to translate business and mission requirements into technical solutions.
• Perform unit testing, integration testing, and code reviews to ensure software quality and reliability.
• Track vendor software releases, upgrades, and patch management activities.
• Utilize DevOps tools and CI/CD pipelines to automate software development, testing, and deployment.
• Support cloud-native application development within AWS, Azure, or similar cloud environments.

Skills

React

Node.js

Elasticsearch

LLMs

RAG

APIs

CI/CD

DevSecOps

AWS

Azure

Tools

Express

Jest

Git

Jenkins

Nexus

Job description

Fantom Corporation in Chantilly, VA is seeking a Full Stack Software Engineer to design scalable web apps, implement AI-powered search, and integrate LLMs.

You will build SPAs with React, develop RESTful APIs with Node.js, and work with Elasticsearch for enterprise search, RAG pipelines, and vector search.

Join a team practicing Lean Agile, DevSecOps, and cloud-native development across AWS/Azure to deliver mission-critical solutions.