FLEX Principal Engineer – Web Performance

As a Principal Engineer Web Performanceyou will play a critical role in improving the speed reliability and stability of traveler facing web experiences across Marriotts digital ecosystem including homepage search and reservation flows.

In this role you will work across multiple product teams to establish performance standardsproactively identify performance regressionsand improve how teams measure and understand the real world impact of their changes. You will partner closely with engineers product teams and platform stakeholders to ensure performance is considered early and continuously throughout the development lifecycle.

In addition to performance analysis and observability you will contribute to the evolution of internal performance reporting applications built with and PostgreSQL helping teams self serve historical trends release comparisons and cohort based performance insights. These tools are treated as internal products with roadmaps UX considerations and a focus on long term maintainability.

This role emphasizes technical leadership and influence without direct authority enabling teams to build fast resilient experiences while continuously raising the bar on performance engineering practices.

Key Responsibilities Performance Monitoring Analysis and Automation

• Proactively identify web performance regressions trends and anomalies using data from observability and monitoring platforms (e.g. RUM synthetic monitoring application telemetry).

• Analyze performance data across releases pages and user cohorts to surface actionable insights for engineering teams.

• Collaborate with teams to define and refine performance budgets thresholds and guardrails that help prevent regressions.

• Design and implement automated alerts reports and regression detection mechanisms to reduce time to diagnosis and manual investigation.

• Help teams understand performance trade offs and incorporate performance considerations into day to day engineering decisions.

• Contribute to evolving performance standards and best practices in collaboration with platform and product partners.

Internal Performance Tooling ( / PostgreSQL)

• Contribute to the design and development of internal performance reporting applications built with and PostgreSQL.

• Design APIs and data access patterns that support performant flexible access to performance metrics and historical data.

• Perform data modeling and query optimization in PostgreSQL to support scalable historical trend analysis and comparisons.

• Build and refine front end data visualizations and user experiences that make performance data intuitive and actionable.

• Treat internal tools as products by contributing to roadmaps usability improvements and long term technical health.

• Support use cases such as before/after release comparisons page level analysis and cohort based performance views.

Collaboration Influence and Enablement

• Work closely with product engineering teams to embed performance thinking into feature development and delivery.

• Partner with platform infrastructure and analytics teams as needed to understand system behavior and data sources.

• Influence engineering teams without direct ownership by providing guidance tooling and clear technical recommendations.

• Help teams learn how to reason about performance diagnose issues and evaluate the impact of changes.

• Communicate technical findings clearly to a range of audiences including engineers product partners and leadership when appropriate.

Qualifications

• 10 years of professional experience in software engineering with strong full stack development expertise.

• Deep experience building and maintaining modern web applications using technologies such as JavaScript/TypeScript React and .

• Strong SQL skills with hands on experience in PostgreSQL including data modeling and query optimization.

• Experience designing and consuming APIs to support data driven applications.

• Proven ability to work across multiple teams and codebases influencing outcomes without direct authority.

• Strong engineering fundamentals including code quality system design and maintainability.

• Experience building or contributing to internal platforms or developer facing tools.

Preferred Qualifications

• Experience working with web performance metrics such as Core Web Vitals and an understanding of synthetic vs. real user monitoring data.

• Familiarity with observability monitoring and alerting tools used in large scale web platforms.

• Experience presenting technical data through dashboards visualizations slide decks or written narratives.

• Exposure to cloud native architectures CDNs or distributed systems.

• Interest in or experience with AI assisted performance analysis anomaly detection or automated insights.

• Strong communication skills and the ability to explain complex technical concepts in a clear pragmatic way.

At Marriott International we are dedicated to being an equal opportunity employer welcoming all and providing access to opportunity. We actively foster an environment where the unique backgrounds of our associates are valued and greatest strength lies in the rich blend of culture talent and experiences of our are committed to non-discrimination on any protected basis including disability veteran status or other basis protected by applicable law.