Principal Full Stack Engineer

Description We deliver our customers peace of mind every day by helping them protect what they value most. Our passion for placing the customer at the center of everything we do is driving a transformational shift at Liberty Mutual. Operating as a tech startup within a Fortune 100 company, we are leading a digital disruption that will redefine how people experience insurance.At Liberty, you'll thrive in a hybrid setting that fosters in-person collaboration, innovation and growth. This approach optimizes both remote and in-person interactions, enabling you to connect and ideate with your team and deepen valuable relationships across the company, while still enjoying the flexibility of remote work for focused tasks and projects. This role has a hybrid work schedule (2 days onsite) and we are considering candidates based in Portsmouth, NH, and Boston, MA.You must be authorized to work in the United States without employer sponsorship now or in the future. We will not sponsor employment visas. Candidates who will require future sponsorship, including candidates on CPT/OPT/STEMOPT who will require future sponsorship, are not eligible to apply.Job Introduction:We are seeking a Principal Full Stack Engineer to join the Global Enterprise Services team within Global Finance Tech (GFT). In this role, you will serve as the technical leader for the Jet Setters squad, setting the technical direction for and driving the architecture, design, and delivery of back-end and full-stack applications. The Jet Setters squad owns a portfolio of 22 GFT products, including the Reservation System, Contracts Portal, Non-Employee Portal, Corporate Aviation Flight Approvals and Business Impact Analysis (BIA). As the most senior engineer on the squad, you will partner with product owners, business partners, architects and engineering leadership to shape the long-term technical roadmap and deliver secure, reliable, and scalable solutions including the strategic integration of AI-powered capabilities that enhance user experiences and operational efficiency. You will act as a force multiplier: mentoring engineers, elevating engineering standards, and influencing technical decisions. About the job:Set the technical vision and architecture strategy for the squad’s portfolio, balancing immediate delivery needs with long term scalability and maintainability.Lead the design and development of complex, high impact applications and shared platform capabilities.Drive architectural decisions and establish patterns, frameworks, and reusable components adopted across teams.Provide technical leadership and hands-on mentorship to engineers, fostering growth and raising the bar for engineering quality.Establish and champion engineering guidelines, standards, and best practices across the organization.Review code and technical designs, providing actionable feedback and ensuring adherence to architectural and quality standards.Own and evolved automated testing, CI/CD, and observability strategies to ensure reliability and operational excellence.Lead impact analyses and technical solutioning for the most complex, systemic, and high-risk changes.Develop and recommend technical alternatives for ambiguous, large scale, or systemic problems.Guide production support strategy, including complex incident triage, root cause analysis, and defect resolution.Author and steward architecture documentation, technical specifications, and production support artifacts.Define and lead the strategy for integrating AI-powered features and capabilities across existing and new product lines.Partner with product and business leaders to translate business objectives into technical strategy and influence prioritization and roadmaps.Collaborate with your team’s solutions engineer and architects on enterprise-wide technical initiatives and governance. Qualifications Bachelor’s degree in technical or business discipline.Minimum 8+ years of Full Stack Engineering experience, including demonstrated experience as a technical lead or principal engineer.Deep expertise in applying object-oriented design patterns, architectural patterns, and distributed systems principles.Advanced proficiency with TypeScript, React, Node.js, AWS Lambda, AWS S3, SQL, Spring Boot, GitHub Actions.Experience with GitHub Copilot or similar products such as Claude Code, including driving adoption of AI-assisted development practices across teams.Proven track record architecting, delivering, and supporting multiple complex, large scale production applications.Expert knowledge of IT concepts, strategies, and methodologies, with the ability to set technical direction across teams.Demonstrated experience leading engineering teams technically, mentoring engineers, and driving adoption of best practices.Deep experience with Agile methodologies (e.g., Scrum) and scaling engineering practices.Expertise designing and optimizing CI/CD pipelines and tooling, and defining testing frameworks, strategies, and best practices.Proven ability to influence stakeholders and drive alignment across engineering, product, and business partners.Exceptional analytical, problem-solving, and decision-making skills, with strong ownership and initiative.Excellent oral and written communication skills, including the ability to communicate complex technical concepts to technical and nontechnical audiences.Team-oriented leader, with strong collaboration, prioritization, and adaptability skills.Nice to Have Qualifications: AI & Emerging TechnologiesUnderstanding of AI/ML concepts and how they apply to software product development at scale.Experience architecting and integrating Large Language Model (LLM) APIs (e.g., OpenAI, Azure OpenAI, AWS Bedrock) into production applications.Hands-on experience with Retrieval-Augmented Generation (RAG) patterns, including vector databases and embedding models.Experience designing solutions with AI orchestration frameworks.Expertise in prompt engineering techniques and best practices for building reliable, production-grade AI-driven features.Understanding of responsible AI principles, including bias awareness, explainability, and data privacy considerations.Experience designing, building, or consuming AI-powered APIs and microservices in a cloud-native environment (AWS preferred). About Us Pay Philosophy: The typical starting salary range for this role is determined by a number of factors including skills, experience, education, certifications and location. The full salary range for this role reflects the competitive labor market value for all employees in these positions across the national market and provides an opportunity to progress as employees grow and develop within the role. Some roles at Liberty Mutual have a corresponding compensation plan which may include commission and/or bonus earnings at rates that vary based on multiple factors set forth in the compensation plan for the role.At Liberty Mutual, our goal is to create a workplace where everyone feels valued, supported, and can thrive. We build an environment that welcomes a wide range of perspectives and experiences, with inclusion embedded in every aspect of our culture and reflected in everyday interactions. This comes to life through comprehensive benefits, workplace flexibility, professional development opportunities, and a host of opportunities provided through our Employee Resource Groups. Each employee plays a role in creating our inclusive culture, which supports every individual to do their best work. Together, we cultivate a community where everyone can make a meaningful impact for our business, our customers, and the communities we serve. We value your hard work, integrity and commitment to make things better, and we put people first by offering you benefits that support your life and well-being. To learn more about our benefit offerings please visit: Liberty Mutual is an equal opportunity employer. We will not tolerate discrimination on the basis of race, color, national origin, sex, sexual orientation, gender identity, religion, age, disability, veteran's status, pregnancy, genetic information or on any basis prohibited by federal, state or local law.Fair Chance NoticesCaliforniaLos Angeles IncorporatedLos Angeles UnincorporatedPhiladelphiaSan FranciscoJob SummaryID: 2026-219520Position Type: Full-TimeMinimum Salary: USD $120,000.00/Yr.Maximum Salary: USD $225,000.00/Yr.Typical Starting Salary: $142,800 - $201,300Flexible Time Off Annual Accrual - days: 20