Principal Software Engineer

Job Summary
Our client, a major technology solutions company, needs a Principal Software Engineer for their Security Harness Engineering team. This is a hands-on engineering role building AI-powered tooling that secures and validates code produced by AI coding assistants and agents. The ideal candidate has actually built and shipped agentic AI systems in production, and can own the full delivery lifecycle on their own.



This position is W-2 only. We do not work with third-party firms or C2C arrangements for this role.

Contract Details

• Contract Length: 52 weeks
• Location: Round Rock, TX
• Work Model: Onsite

Core Responsibilities

• Design, build, and deploy AI-powered capabilities across the SDLC, including spec-driven development workflows and guardrails for AI-generated code
• Build SDLC skills and agent tooling, including automated security checks like design review, dependency/supply-chain analysis, and static/dynamic analysis orchestration
• Integrate with enterprise systems (source control, CI/CD, ticketing, security scanning, identity) through APIs, webhooks, and protocols like MCP
• Work with engineering, security, product, and leadership stakeholders to define requirements and weigh trade-offs
• Apply solid architecture and systems design practices around service boundaries, data models, secure defaults, and observability
• Mentor junior developers and act as a technical SME for IT leadership and other teams
• Lead moderate to high budget projects, sometimes more than one at a time, and manage milestones and estimates

Required Skills/Experience (Must-Haves)

• Strong programming skills in Python, TypeScript/JavaScript, Go, or similar
• Built and deployed AI-based solutions in production with measurable business or operational impact
• Hands-on with modern AI/LLM development: context engineering, agentic system design (agent loops, multi-agent orchestration, tool/function calling), context window management and token budgeting, and evaluating AI system quality and safety
• Solid grasp of software architecture and systems design, including API design, event-driven patterns, and data modeling for scale
• Experience building or deploying applications with large-scale impact
• Experience integrating multiple systems and platforms (REST/GraphQL APIs, CI/CD pipelines, cloud services, enterprise tooling)
• Can work independently across the full delivery lifecycle and take ownership of results
• Strong communication skills, able to talk to both technical and business audiences
• Working knowledge of secure development practices and enterprise security/compliance needs

Preferred Skills/Experience (Nice-to-Haves)

• Bachelor's or Master's in Computer Science or related field, or equivalent practical experience
• Experience applying AI in a security domain, like AppSec, DevSecOps, code analysis, threat modeling, firmware security, or software supply-chain security
• Familiarity with secure-by-design principles and frameworks (OWASP Top 10 for LLM Applications, NIST SSDF)
• Experience with MCP, building agent skills/tools, or extending AI coding assistants like Claude Code, GitHub Copilot, Cursor, or Devin
• Experience with AI evaluation frameworks, guardrails, prompt/response caching, and LLMOps in production

Key Competencies and Behaviors

• Security-First Mindset
• Stakeholder Communication
• Team Collaboration
• Continuous Learning
• End-to-End Ownership

Work Environment

• Location: Round Rock
• Fully onsite

Compensation & Benefits

• Pay Range: The approximate pay range for this position is between $50.00 and $72.00. Please note that the pay range provided is a good faith estimate. Final compensation may vary based on factors including but not limited to background, knowledge, skills, and location. We comply with local wage minimums.
• Medical, Dental, & Vision Insurance Plans
• Employee-Owned Profit Sharing (ESOP)
• 401K offered

About KellyMitchell
At KellyMitchell, our culture is world class. We're movers and shakers! We don't mind a bit of friendly competition, and we reward hard work with unlimited potential for growth. This is an exciting opportunity to join a company known for innovative solutions and unsurpassed customer service. We're passionate about helping companies solve their biggest IT staffing & project solutions challenges. As an employee-owned, women-led organization serving Fortune 500 companies nationwide, we deliver expert service at a moment's notice.



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