Principal Engineer, Solutions Architecture

Overview

LMI is seeking a Principal Engineer, Solutions Architecture with strong hands-on development skills and a talent for agentic AI to join the Chief Technology Office development team. This role is for someone who doesn't just write code — they see the whole system, spot the real problem behind the request, and design the solution before they build it. You'll move fast across a portfolio of high-stakes programs, using agentic AI as leverage to turn architecture into working software at speed. This position requires an active Secret security clearance.

LMI is a new breed of digital solutions provider dedicated to accelerating government impact with innovation and speed. Investing in technology and prototypes ahead of need, LMI brings commercial-grade platforms and mission-ready AI to federal agencies at commercial speed. Leveraging our mission-ready technology and solutions, proven expertise in federal deployment, and strategic relationships, we enhance outcomes for the government, efficiently and effectively. With a focus on agility and collaboration, LMI serves the defense, space, healthcare, and energy sectors — helping agencies navigate complexity and outpace change. Headquartered in Tysons, Virginia, LMI is committed to delivering impactful results that strengthen missions and drive lasting value.

Responsibilities

Responsibilities:

Providing direct support to multiple customers, this Principal Engineer, Solutions Architecture will:

• Diagnose before you build: Analyze customer requirements and program objectives to uncover the underlying problem, not just the stated request, and design solutions that align with mission needs.
• Architect across the stack: Design end-to-end solutions — from data model to API to UI — that are scalable, maintainable, and fit the constraints of large, complex government programs.
• Leverage agentic AI as a force multiplier: Use advanced agentic AI tools to rapidly prototype, extend, and integrate new functionality into existing code stacks, compressing the distance between idea and working system.
• Drive high-impact, ambiguous problems: Make quick, high-impact contributions to strategically critical projects, often stepping into programs with incomplete requirements and shaping them into a coherent technical plan.
• Translate between worlds: Collaborate with development teams, stakeholders, and technical leads to identify pain points in existing systems, propose creative solutions, and build consensus around the right architecture.
• Move fluidly across programs: Transition seamlessly between programs, applying technical and design judgment to prioritize the highest-impact initiatives.
• Close the loop: Facilitate integrations, resolve technical challenges, and adhere to development timelines within multidisciplinary teams.
• Build for the mission, not just the ticket: Ensure compliance with security protocols, government standards, and industry best practices across all projects.
• Multiply your impact through documentation: Document technical solutions, design rationale, and architectural decisions for knowledge transfer between teams and programs.
• Validate the design, not just the code: Conduct rigorous testing to guarantee performance, scalability, and reliability of updated or newly architected systems.

Qualifications

Minimum Qualifications

• Active Secret clearance
• 3–5 years applying full-stack development in a production environment.
• Demonstrated solutions mindset: Experience translating ambiguous requirements into a technical design or architecture, not just implementing pre-defined tickets.
• Experience with agentic AI coding tools: demonstrated proficiency using tools to enhance existing code stacks at scale.
• Proven full-stack development experience: minimum of 3–5 years developing, maintaining, and improving front-end and back-end systems.
• Proficient in at least one back-end language (Python preferred) and one front-end framework/tool (TypeScript preferred).
• Experience designing and consuming RESTful APIs for integration across systems.
• Strong foundational skills across relational (e.g., PostgreSQL, MySQL, SQL Server) and non-relational (e.g., MongoDB) databases.
• Comfortable operating in agile environments and collaborating across multidisciplinary teams.
• Version control proficiency: Git (GitLab preferred).
• Experience with testing, security, DevSecOps, and CI/CD processes.
• Strong communication and influence skills: able to pitch a technical solution to both engineers and non-technical stakeholders, and defend the "why" behind an architecture, not just the "how."

Desired Skills

• Advanced proficiency in agentic AI tools, including designing multi-step or multi-agent workflows to accelerate development.
• Experience with cloud environments (AWS, Azure, or Google Cloud) for designing and deploying cloud-based solutions.
• Microservices and containerized architecture experience (Docker, Kubernetes).
• UI/UX design sensibility — knowledge of React, Vue.js, or Angular used in service of better user outcomes, not just implementation.
• Infrastructure-as-code fluency (Terraform, Ansible) as part of a broader DevSecOps practice.
• Data engineering experience: ETL pipelines, data pipeline management, real-time analytics.
• Security certifications (Security+, CISSP) highly desirable.
• Advanced Agile/SAFe experience, including shaping sprint planning around architectural priorities.
• A track record of proposing solutions others hadn't considered — whether that's a novel integration pattern, a smarter data flow, or a way to use AI tooling that saved a program significant time

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