Principal Engineer

Principal Engineer, Applied AI (TS/SCI)Hybrid or Remote. Travel to the DMV area and customer sites may be required.SIXGEN's mission is to deliver agile, mission-ready cybersecurity solutions that empower government and critical infrastructure organizations to stay ahead of advanced cyber threats. We combine innovation, deep expertise, and cutting-edge capabilities to uncover vulnerabilities, protect vital systems, and ensure operational superiority in an ever-evolving digital landscape.Position OverviewPosition: Principal Engineer, Applied AIJob Type: Full TimeLocation: Hybrid or Remote. Travel to the DMV area and customer sites may be required.Clearance Requirements: TS/SCITravel: Up to 10%, depending on location and customer needsAbout The TeamSIXGEN supports cyber and intelligence missions by helping government and commercial organizations overcome global cybersecurity challenges. Our highly skilled operators conduct research and assessments based on real-world threats, simulating adversaries and malicious actors to deliver actionable findings on critical assets and infrastructures. Our program planners advise mission owners to bring rapid solutions to intelligence leaders. Using innovative processes, tools, and techniques, we predict and overcome cybersecurity vulnerabilities.SIXGEN is investing heavily in applied AI as a force multiplier for our engineers, operators, researchers, and customers. Our goal is not simply to incorporate AI into existing products, but to continually identify new ways that AI-native development techniques, models, agents, and automation can change how cyber capabilities are researched, built, and operated.The Principal Engineer, Applied AI will operate at the leading edge of that effort.This is a highly technical individual contributor role for an engineer who is comfortable working ahead of established product roadmaps and engineering patterns. The Principal Engineer will continuously evaluate emerging AI technologies, development tools, architectures, and techniques; build working prototypes; test technical assumptions; and establish viable implementation paths before larger engineering teams commit to them.The role is intentionally exploratory. Rather than starting with a fully specified product requirement, this engineer will often begin with questions: Can this new approach materially improve how we build software? Can an agent perform this workflow reliably? Can a new model unlock a capability that was previously impractical? What would it take to operationalize this safely in a classified environment?The Principal Engineer will turn those questions into evidence.Success in this position means reducing technical uncertainty. The engineer will rapidly separate promising technologies from hype, demonstrate what is possible through working software, identify architectural constraints early, and hand engineering teams proven approaches they can confidently turn into durable products and mission capabilities.What You'll DoExplore emerging AI technologies and techniques, continuously evaluating new models, agent frameworks, developer tools, inference platforms, orchestration approaches, and AI-native software development patterns for their relevance to SIXGEN's missions and products.Build rapid technical prototypes, turning promising ideas into working software quickly enough to validate assumptions, expose limitations, and determine whether broader engineering investment is warranted.Prove technical concepts before product implementation, establishing reference architectures, integration patterns, evaluation criteria, and implementation approaches that engineering teams can build upon.De-risk new technology adoption, identifying performance, reliability, security, scalability, data, infrastructure, and operational constraints before they become downstream product problems.Advance AI-enabled software development, experimenting with coding agents, AI-assisted development environments, autonomous engineering workflows, model-driven testing, code analysis, and other techniques that can materially increase engineering velocity and capability.Develop AI-enabled cyber capabilities, exploring how models and autonomous systems can augment vulnerability research, reverse engineering, malware analysis, exploit development, offensive and defensive operations, and other specialized technical workflows.Design and evaluate agentic systems, including tool use, multi-step reasoning, memory, orchestration, human-in-the-loop controls, evaluation frameworks, and mechanisms for improving reliability in complex operational workflows.Create reusable technical foundations, converting successful experiments into reference implementations, libraries, patterns, technical documentation, and architectural guidance that product and engineering teams can adopt.Work directly with engineers and operators, identifying high-value problems where new AI capabilities can materially improve effectiveness, speed, scale, or quality.Transfer successful prototypes into engineering, partnering closely with product and engineering teams to ensure experimental capabilities can transition into maintainable, secure, production-quality systems.Establish technical evidence, not just demonstrations, developing evaluations and benchmarks that measure whether new approaches actually improve capability, reliability, cost, performance, or developer productivity.Challenge existing assumptions, identifying areas where AI-native architectures or development approaches may enable fundamentally different solutions rather than incremental improvements to existing systems.Stay deeply hands-on, writing code, integrating models and tools, designing architectures, debugging systems, running experiments, and building enough of each concept to understand how it behaves in the real world.Communicate findings clearly, providing engineering leadership with concise technical recommendations on what SIXGEN should adopt, continue researching, build internally, purchase, or avoid.Support technical demonstrations and customer engagements, particularly when emerging capabilities need to be demonstrated, evaluated, or translated into potential mission applications.Help shape the technical direction of applied AI at SIXGEN, serving as a trusted senior technical authority on emerging AI engineering practices and their practical application.Required Qualifications12+ years of experience in software engineering, cybersecurity engineering, applied research, or related technical disciplines, with significant experience operating as a senior or principal-level individual contributor.Exceptional hands-on software engineering ability, with a track record of rapidly designing, building, and evaluating complex technical systems.Demonstrated experience taking ambiguous technical ideas from initial hypothesis through working prototype and technical validation.Direct experience building AI-enabled applications or systems, including model integration, APIs, tool use, workflow orchestration, retrieval, evaluation, and production integration.Strong working knowledge of modern LLM application architectures and agentic system design, including the strengths and limitations of current models.Experience evaluating emerging technologies and making sound technical judgments about maturity, applicability, architectural fit, and implementation risk.Ability to move quickly in poorly defined problem spaces without requiring extensive product specifications or established engineering patterns.Strong software architecture fundamentals and the ability to distinguish between code built to answer a technical question and systems designed for long-term production use.Experience developing prototypes that successfully transitioned into larger engineering efforts, products, platforms, or operational capabilities.Ability to design meaningful experiments and evaluations rather than relying solely on qualitative demonstrations.Deep familiarity with at least one or more of the technical domains relevant to SIXGEN's work, such as cybersecurity, offensive security, vulnerability research, reverse engineering, malware analysis, distributed systems, developer tooling, or autonomous systems.Ability to communicate complex technical findings clearly to engineers, technical leadership, executives, and customers.Active TS/SCI clearance.U.S. Citizen.Bachelor's degree in Computer Science, Computer Engineering, Math, or a related technical field, or equivalent depth of professional experience.Preferred QualificationsExperience building or evaluating autonomous or semi-autonomous systems for cybersecurity, software engineering, or other complex technical domains.Deep familiarity with AI-assisted software engineering tools, coding agents, development environments, and emerging approaches to AI-native software development.Experience with model evaluation, benchmarking, observability, and reliability testing for LLM or agent-based systems.Experience developing custom tools, environments, or harnesses that allow AI systems to interact with software, infrastructure, cyber tooling, or external systems.Familiarity with open-source and commercial model ecosystems, including model selection, inference architectures, fine-tuning, retrieval, and deployment tradeoffs.Experience working in research-oriented engineering organizations, advanced development groups, startups, internal incubators, or other environments where engineers are expected to rapidly explore uncertain technical opportunities.Background in offensive or defensive cyber operations, particularly automation of specialized technical workflows.Experience operating in classified or controlled environments and understanding the implications of applying modern AI technologies within those constraints.Familiarity with AI security, model risk, data handling, prompt injection, tool-use security, and other challenges associated with deploying AI-enabled systems in sensitive environments.A history of creating technical prototypes or internal tools that materially changed