Software Test Engineer III (Clearance Required)

Company: Sierra Space
Location: Louisville
Posted on: April 2, 2026

Job Description:

Sierra Space Careers: At Sierra Space, we build the missions and systems that keep our world secure in the domain above Earth. Sierra Space team members share a spirit of innovation and collaboration and a belief that we can deliver on the boldest missions in space today. Together with our customers, we aim to safeguard our nation, sustain human presence in space, and secure the freedom of operations in low Earth orbit and beyond. Our success is measured by the trust of those who rely on what we build and deliver, and our technologies keep the United States and its allies mission-ready throughout space. We are mission-driven, and together, we are an extraordinary team. About the Role The Software Test Engineer III is responsible for leading testing processes, designing comprehensive test plans, developing testing strategies, and architecting testing frameworks for large and complex aerospace software projects. You will participate in the development and execution of comprehensive test plans, test cases, and test procedures to verify the functionality, performance, and reliability of aerospace software systems used in space vehicles and other aerospace applications. In this role you will also be responsible for coordinating testing activities, ensuring thorough coverage of all requirements, and performing defect triage. Your role will involve significant interaction with cross-functional teams, including software development, systems engineering, and quality assurance to ensure compliance with technical specifications and adherence to software quality standards. You will also mentor and guide junior engineers, fostering a culture of continuous improvement and technical excellence while contributing to the success of complex space missions. Key responsibilities include developing and executing test plans, cases, and procedures to ensure software functionality, performance, and reliability. This involves creating and reviewing automated test scripts, collaborating with developers to design effective test strategies, and managing the defect lifecycle from discovery to resolution. Additional duties include optimizing testing processes, performing regression testing, maintaining test documentation, and implementing automated tools to enhance efficiency. The role also requires mentoring junior engineers, participating in code reviews, staying updated on industry best practices, and designing complex test systems to meet project requirements. About You Our mission is driven by an unyielding commitment to advancing space-based technology in service of our customers and safeguarding national security. We seek individuals who are passionate about innovating beyond boundaries and relentlessly pursuing solutions that protect, preserve and empower – to join us in this critical mission. We’re looking for team members who align with our values, mission and goals – while also meeting the minimum qualifications below. The preferred qualifications are a bonus, not a requirement. Minimum Qualifications: Requires bachelor's degree in a related field (or equivalent work experience in lieu of degree or master's 3 yrs experience). Typically, 5 years of related experience. Expertise in one to multiple programming languages and advanced understanding of software development principles. Ability to design and architect complex software systems. Experience with different software development methodologies such as Agile and Scrum/Kanban. Strong problem-solving skills. Ability to mentor and guide other engineers. An active Top Secret U.S. Security Clearance is required. Preferred Qualifications: Proficiency with Linux-based and Windows-based software development environments. Experience with automated testing tools and frameworks. Knowledge of software testing methodologies and best practices. Familiarity with continuous integration and continuous deployment (CI/CD) processes. Understanding of software development lifecycle (SDLC) and agile methodologies. Ability to rapidly work with minimal supervision on projects involving both small and large engineering teams. Ability to collaborate effectively with Software Engineers, Systems Engineers, and other Testers Excellent problem-solving skills and the ability to work effectively in a fast-paced, collaborative environment. Experience with testing software systems used in aerospace or other highly regulated industries. Proficiency in scripting languages such as Python, JavaScript, or Shell. Familiarity with common object-oriented software design patterns. Knowledge of security testing practices and tools. Familiarity with cloud-based testing environments and tools. Experience with test management tools such as JIRA, TestRail, or similar. Experience in leading and managing testing projects and teams. Strong communication and interpersonal skills, with the ability to effectively convey complex technical concepts to both technical and non-technical stakeholders. Practical experience utilizing software-in-the-loop and hardware-in-the-loop test methods. Familiarity with fault-tolerant software design and safety-critical systems. Desire to work with, learn from, and mentor others. Strong understanding of software system architectures and design patterns Compensation : Pay Range: $126,610.00 - $174,088.75 Your actual base compensation will be determined on a case-by-case basis and may vary based on job-related knowledge and skills, education, experience, internal equity and market competitiveness. IMPORTANT NOTICE: This position requires current/active Top Secret U.S. Security Clearance. U.S. Citizenship status is required as this position needs an active U.S. Security Clearance for employment. Non-U.S. Citizens may not be eligible to obtain a security clearance. The Department of Defense Consolidated Adjudications Facility (DoD CAF), a federal government agency, handles the adjudicative aspects of the security clearance eligibility process for industry applicants. Adjudicative factors which affect the outcome of the eligibility determination include, but are not limited to, allegiance to the U.S., foreign influence, foreign preference, criminal conduct, security violations and illegal drug use. Elevate Your Career At Sierra Space, we are committed to your personal and professional development. We empower you to make profound and meaningful contributions and foster a vibrant culture of collaboration, where teamwork ignites breakthrough innovations. We also offer a generous benefit package, including medical, dental, and vision plans, 401(k) with 150% match up to 6%, life insurance, 3 weeks paid time off, and more. Sierra Space is an industry-leading space and defense technology company providing satellites, spacecraft, and enabling mission systems and components. We deliver mission-proven technologies to our customers that safeguard our nation, protect space-based assets and enable space exploration. Application Deadline: This role will remain posted until a qualified pool of candidates is identified. Please note: Sierra Space does not accept unsolicited resumes from contract agencies or search firms. Any unsolicited resumes submitted to our website or to Sierra Space team members not through our approved vendor list or Talent Acquisition will be considered property of Sierra Space, and we will not be obligated to pay any referral fees. Sierra Space Corporation is an equal opportunity employer and is committed to working with and providing reasonable accommodations to applicants with disabilities. If you need special assistance or a reasonable accommodation related to applying for employment with Sierra Space or at any stage of the recruitment process, please contact us .

Keywords: Sierra Space, Cheyenne , Software Test Engineer III (Clearance Required), IT / Software / Systems , Louisville, Wyoming