Full Stack Python Engineer

Description

The Health and Services Operation of Leidos is seeking a Full Stack Python Engineer to support a Critical Health program

Candidates MUST:
Be US Citizen or Green Card holders with the ability to obtain a level 5 Public Trust Clearance

AND

Be currently located in the UNITED STATES for the current three consecutive years.

Role is a telecommuting role.

The GRACE team builds and operates the agency's purpose-built AI assistant - a production system used daily by all ARPA-H staff to accelerate healthcare research, program launches, and agency operations. GRACE is a Python-first, full-stack platform built on Chainlit, integrating OpenAI GPT, Anthropic Claude, and Google Gemini models with real-time streaming interfaces, custom Mermaid diagram rendering, GeoJSON map generation, Slack channel search, SharePoint document indexing, and external API connections, all running on Azure in a FedRAMP-aligned environment.

We are hiring a Full Stack Software Development Engineer to backfill a critical seat. You will work on the full vertical: Chainlit application layer, custom component development, Python backend services, API integrations, and production operations.

This is not a role where front-end and backend are handed off between people. You own both. You ship both.

We ship on a weekly cadence. We hold a <4-hour SLA for issue response. The bar is high and the mission is real. We operate with a product-led, customer-obsessed culture and a bias for shipping over planning.

Key Job Responsibilities

Full Stack Application Development (Chainlit + Python Backend)

• Own the GRACE application layer end-to-end - Chainlit lifecycle hooks, chat profiles, session management, streaming configuration, data persistence, and human feedback integration
• Build and extendcustom Chainlit componentsin React/TypeScript for advanced rendering surfaces: Mermaid v11 diagrams, GeoJSON/OpenStreetMaps, Imagen4 image outputs, and multi-model conversation state
• Design, build, and maintainPython backend services and API integrationspowering GRACE's tool-calling architecture: internal document search (SharePoint/vector search), Dimensions API (, Google Search, Slack channel history, and Imagen4 image generation
• Own theEntra ID OAuth 2.0/OIDC authentication integrationwithin Chainlit, ensuring seamless and secure SSO flows
• Design and maintainsecure file handling pipelinesall type types - validation, sanitization, storage, and retrieval
• Build and maintainmulti-LLM routing logicacross OpenAI GPT, Anthropic Claude, and Google Gemini - including model switching, streaming completions, tool-call orchestration, and fallback handling

Customization & Front-End Extension

• Extend Chainlit's front-end via CSS/JS customization,
• Write custom React components where Chainlit's native rendering falls short - Mermaid v11 is a live example of this; you will own and evolve it
• Ensure all rendering surfaces meetaccessibility standards

Collaboration & Customer Obsession

• Work directly with the GRACE product team and ARPA-H stakeholders to translate user feedback into shipped improvements on a weekly cadence
• Lead code reviews, set engineering standards, and mentor teammates
• Contribute to architecture decisions, technical documentation, and internal engineering wikis

Basic Qualifications

• Bachelor's degree in computer science or data science
• 7+ years of non-internship professional software development experience
• 7+ years ofPythonas a primary programming language in production environments
• 7+ years of leading design or architecture (design patterns, reliability and scaling) of new and existing systems experience
• Experience building and shippingproduction LLM/AI chat applications- streaming, tool-calling, multi-turn conversation state management
• Experience withChainlitor a comparable Python-first conversational AI framework (Streamlit, Gradio, or equivalent) in a production context
• Experience building and owningREST APIs and backend service integrationsend-to-end
• Experience withOAuth 2.0 / OIDC authentication flowsin production systems
• Experience withcloud infrastructure(Azure preferred) and containerization (Docker)
• Experience with modern JavaScript/TypeScript tooling and frameworks
• Experience working with relational databases (eg PostgreSQL), including schema design and writing efficient queries.
• Experience as a mentor, tech lead, or leading an engineering team

Preferred Qualifications

• 7+ years of full software development life cycle, including coding standards, code reviews, source control management, build processes, testing, and operations experience
• Chainlit-specific experience: custom component development,
• Experience writingcustom React/TypeScript componentsand managing application state (eg Recoil, Redux, or similar)
• Experience with a modern UI frameworks and styling approaches (MUI, Tailwind, or similar)
• Experience withmulti-LLM API integration(OpenAI, Anthropic Claude, Google Gemini) including streaming completions and tool-call orchestration
• Experience withvector databases and semantic search pipelines(Azure AI Search, pgvector, Pinecone, or equivalent)
• Experience inFedRAMP, FISMA, or NIST 800-53compliant Azure environments
• Experience withCI/CD pipelines(GitHub Actions or equivalent) and production observability tooling
• Experience at a high-velocity startup or product-led organization with weekly ship cadences

If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo - because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 - and moving faster than anyone else dares.

For U.S. Positions: While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above.

The Leidos pay range for this job level is a general guideline onlyand not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.

About Leidos

Leidos is an industry and technology leader serving government and commercial customers with smarter, more efficient digital and mission innovations. Headquartered in Reston, Virginia, with 47,000 global employees, Leidos reported annual revenues of approximately $16.7 billion for the fiscal year ended January 3, 2025. For more information, visit www.Leidos.com.

Pay and Benefits

Pay and benefits are fundamental to any career decision. That's why we craft compensation packages that reflect the importance of the work we do for our customers. Employment benefits include competitive compensation, Health and Wellness programs, Income Protection, Paid Leave and Retirement. More details are available at www.leidos.com/careers/pay-benefits.

Securing Your Data

Beware of fake employment opportunities using Leidos' name. Leidos will never ask you to provide payment-related information during any part of the employment application process (i.e., ask you for money), nor will Leidos ever advance money as part of the hiring process (i.e., send you a check or money order before doing any work). Further, Leidos will only communicate with you through emails that are generated by the Leidos.com automated system - never from free commercial services (e.g., Gmail, Yahoo, Hotmail) or via WhatsApp, Telegram, etc. If you received an email purporting to be from Leidos that asks for payment-related information or any other personal information (e.g., about you or your previous employer), and you are concerned about its legitimacy, please make us aware immediately by emailing us at LeidosCareersFraud@leidos.com.

If you believe you are the victim of a scam, contact your local law enforcement and report the incident to the U.S. Federal Trade Commission.

Commitment to Non-Discrimination

All qualified applicants will receive consideration for employment without regard to sex, race, ethnicity, age, national origin, citizenship, religion, physical or mental disability, medical condition, genetic information, pregnancy, family structure, marital status, ancestry, domestic partner status, sexual orientation, gender identity or expression, veteran or military status, or any other basis prohibited by law. Leidos will also consider for employment qualified applicants with criminal histories consistent with relevant laws.

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