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# Principal Software Engineer in Mundelein

- **Company:** Energy Jobline
- **Location:** Mundelein, IL, United States (Remote available)
- **Experience:** Expert
- **Contract:** Permanent contract
- **Skills:** Artificial Intelligence, Amazon Web Services, Application Integration Architecture, Microsoft Azure, Cloud Computing, Amazon DynamoDB, Python (Programming Language), PostgreSQL, Node.Js, NoSQL, Next.js, Software Engineering, TypeScript, ReactJS, Retrieval-Augmented Generation, Large Language Models, Multi-Agent Systems, Prompt Engineering, Software Application Programming, Backend, Fastapi, Graphql
- **Published:** October 27, 2026
- **Apply:** https://www.energyjobline.com/job/principal-software-engineer-mundelein-32078043

## About the Role

Candidates must be US living in the DC area and must be able to successfully go through the government security clearance process. The ideal candidate will already hold a US security clearance and/or have worked with government authorities or government customers in the past., * Full-stack experience: 10+ years of professional software engineering experience, including significant full-stack work on customer-facing applications. Candidates with 10 to 15 years' experience are particularly well suited.
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 * Strong front-end experience: for example React, Next.js or TanStack, using JavaScript and TypeScript, or equivalent.
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 * Strong back-end experience: for example Python (FastAPI) or the Node.js ecosystem, or equivalent. Proven experience designing secure, scalable REST and GraphQL APIs is essential.
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 * Cloud experience: hands-on experience with AWS, Azure or GCP, including relational and NoSQL databases such as PostgreSQL or DynamoDB, or equivalent.
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 * AI and LLM experience: experience building applications that consume LLM APIs, with working knowledge of prompt engineering and patterns such as chain-of-thought, ReAct and RAG, plus context window management. Experience integrating AI and ML models into production systems is .
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 * Technical leadership: demonstrated experience setting architecture direction, mentoring engineers, and making pragmatic trade-offs.

## Description

We're looking for a Principal Full Stack Engineer to lead the design and delivery of secure, scalable web applications supporting a government department. The role bridges traditional full-stack development and AI integration. You'll build scalable applications, implement autonomous agents, and integrate Large Models into production workflows, moving across the front end, back end, cloud infrastructure and AI layers. You'll own architecture decisions, set technical direction, and help make sure the product is robust and secure.