Senior UI/UX Engineer

Join Us in Shaping the Future of Mission-Critical User ExperiencesReady to turn complex mission requirements into intuitive, high-impact user experiences? Join Leidos on the Chinook Program, supporting an Intelligence Community customer, and help design and deliver modern user interfaces that enable mission users to interact with sophisticated systems and data more effectively.As a Sr. UI/IX Engineer, you will play a critical role at the intersection of user experience, interface engineering, design, and mission needs. You’ll work alongside talented software engineers, systems engineers, product owners, testers, and mission stakeholders to transform challenging operational requirements into responsive, intuitive, accessible, and technically sound experiences.This is an opportunity to have a direct impact on an important national security mission while working in a collaborative Agile environment where your ideas, technical expertise, and attention to the user experience will matter.Our Ideal CandidateWe're looking for someone who is more than a front-end developer. You are passionate about how technology feels and functions for the person using it.You naturally ask, "Can we make this simpler?" You enjoy taking complicated requirements and turning them into experiences that are intuitive, efficient, and elegant. You can speak the language of both designers and engineers, understand the realities of delivering software in an Agile environment, and aren't afraid to challenge an approach when you see a better solution.If you're excited by the opportunity to design and engineer the next generation of mission-focused user experiences, we'd love to hear from you.Position may be performed in the following locations below. Please note Gaithersburg, MD is the program’s primary work location.Gaithersburg, MDAlexandria, VAChantilly, VAEnglewood, COSt. Louis, MOTucson, AZ Clearance Level Required:Active Top Secret/SCI with the ability to successfully pass a Polygraph examination.Primary Responsibilities:Lead the design and engineering of modern, intuitive, and responsive user interfaces for mission-critical applications.Translate user needs, mission workflows, and functional requirements into effective UI/IX solutions.Collaborate with product owners, UX/UI designers, software engineers, systems engineers, and mission stakeholders throughout the development lifecycle.Develop reusable UI components, patterns, and design standards that promote consistency and maintainability across the program.Apply user-centered design principles to simplify complex workflows and improve overall usability.Build and refine interactive prototypes and proof-of-concept interfaces to validate concepts with stakeholders.Partner with software engineering teams to ensure designs are implemented accurately, efficiently, and with appropriate performance considerations.Evaluate existing interfaces and identify opportunities to improve usability, accessibility, responsiveness, and overall user experience.Participate in Agile ceremonies, PI Planning, backlog refinement, sprint planning, demonstrations, and retrospectives.Contribute to technical discussions and help establish UI/IX engineering best practices, standards, and patterns.Collaborate with test engineers to ensure UI functionality and user workflows are thoroughly validated.Provide technical mentorship and guidance to less-experienced engineers.Help drive continuous improvement of the program's UI/IX capabilities and development processes.Basic Qualifications:US citizenship is required per contract. Bachelor's degree in Computer Science, Software Engineering, or related field and 8-12 years of prior relevant experience or Master’s with 6-10 years of prior relevant experience.Active Top Secret/SCI with the ability to successfully pass a Polygraph examination.Strong professional experience developing modern web-based user interfaces and user experiences.Proficiency with HTML, CSS, JavaScript/TypeScript, and Python.Experience with modern UI frameworks such as React, Angular, Vue.js, or Django.Demonstrated understanding of responsive design, component-based development, and modern front-end engineering practices.Experience translating complex requirements and user workflows into intuitive interface solutions.Experience working in an Agile/Scrum or SAFe environment.Strong communication and collaboration skills, with the ability to work effectively across technical and non-technical teams.Strong analytical and problem-solving skills with a demonstrated ability to work through complex technical and user-experience challenges.Experience with CI/CD tools (GitLab CI, Jenkins) and agile collaboration tools (JIRA, Confluence).Familiarity with cloud environments such as AWS (C2S or GovCloud) and containerization technologies (Docker, Kubernetes)Understanding of secure coding practices and government system accreditation processes (e.g., RMF, STIGs)Preferred Qualifications:Experience supporting Intelligence Community, DoD, or other mission-focused government programs.Experience working on applications involving complex data visualization, geospatial information, intelligence workflows, or mission systems.Experience with React and TypeScript and modern front-end development tooling.Experience developing or consuming RESTful APIs and integrating UI applications with backend services.Experience with design systems, reusable component libraries, and UI standards.Familiarity with Figma, Adobe XD, Sketch, or similar UX/UI design tools.Experience with accessibility standards such as Section 508/WCAG.Experience developing dashboards, data visualization, maps, or highly interactive mission interfaces.Experience working within a cloud-based environment, particularly AWS.Experience with automated UI testing and tools such as Playwright, Cypress, Selenium, or equivalent.Experience mentoring engineers and providing technical leadership within a multidisciplinary Agile team.#Chinook#NSBAIf you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 — and moving faster than anyone else dares.Original Posting:August 21, 2026For U.S. Positions: While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above.Pay Range:Pay Range $107,900.00 - $195,050.00The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.SummaryLocation: Gaithersburg, MD; Alexandria, VA; St. Louis, MO; Chantilly, VA; Tucson, AZ; Englewood, COType: Full time