Principal Software Engineer ManTech seeks a motivated, career and customer-oriented Principal Software Engineer to join our team in Reston, VA. This is an onsite position. The Principal Software Engineer will work with Network and Systems Engineers to design, build, monitor, maintain, and upgrade all program networks to ensure data is consistently available and flowing properly. Responsibilities include but are not limited to: Designing, developing, programming, and modifying software, systems, applications, and tools, both existing and new in the future Analyzing software and integration requirements and working with team members to determine development and implementation plans Correcting errors by making the appropriate changes and then re-checking the program to ensure the desired result was produced Developing solutions and maintaining support for external data sources and users Building web services, APIs, and other solutions to interface with third-party systems to synchronize data Conducting testing of software to be sure it will produce the desired results and that instructions are correct Organizing and maintaining documentation of developed software and subsequent revisions, so others are able to understand the program Ability and willingness to travel overseas if required Basic Qualifications: 15+ years of relevant software engineering experience Bachelor's degree in a relevant area or five (5) additional years of relevant project management experience in lieu of a degree Strong programming/development skills and hands-on engineering experience (Java & JDK 17+ and/or Javascript/Typescript) Strong experience with REST APIs and standard software engineering tools such as Jira, Git, Gradle/Maven and experience developing software in Linux environments Strong experience with the full data lifecycle, from ingest through display Strong experience using SonarQube for code quality testing Preferred Qualifications: Experience with one or more of the following development technologies: Vue.js, Vite, microservices, Bash, wireframes, UX patterns, Websockets, Groovy/Grails Experience with one or more of the following test technologies: Junit5, AssertJ, Mockito, Postman, Vitest, Eslint Experience with one or more of the following infrastructure/database technologies: MongoDB, Elasticsearch, PostgreSQL, RabbitMQ, Consul, Vault, Nomad, RHEL9 Experience with Cloud technologies and developing in Cloud environments Clearance Requirements: Must have an active/current Secret Security Clearance. Physical Requirements: Must be able to be in a stationary position more than 50% of the time Must be able to communicate, converse, and exchange information with peers and senior personnel Constantly operates a computer and other office productivity machinery, such as a computer The person in this position needs to occasionally move about inside the office to access file cabinets, office machinery, etc.