Senior Software Engineer

Haystack
San Diego, California, United StatesFull-timePosted Sep 14, 2026

About the role

We're working with a leading technology integrator that provides full life cycle services and solutions in technical, engineering, intelligence, and enterprise information technology markets for the U.S. federal government. This organization is redefining ingenuity through deep customer and domain knowledge, delivering systems engineering and integration offerings for large, complex projects.

The Role

Design and develop reliable, modular, and secure software components.

Develop software on a RHEL OS platform, including custom C++ and X windows-based applications, and web-based middleware.

Write applications and policies for security accreditations.

Maintain an active Secret Clearance and be able to obtain a Top Secret clearance.

Travel up to 10% of the time for this on-site role in San Diego, CA.

What You'll Need

Bachelor's degree with nine (9) years of experience, or Master's with seven (7); additional experience accepted in lieu of a degree.

Active Secret Clearance required to start; ability to obtain Top Secret clearance.

Solid Linux (RHEL) familiarity and strong background in web technologies.

Proficiency in JavaScript, React, CSS3, HTML5, and third-party libraries like jQuery and LESS.

Industry experience in designing, building, and maintaining large-scale production systems.

Understanding of low-level operating systems concepts including multi-threading, memory management, networking, and performance.

What's On Offer

Opportunity to work on complex, mission-critical projects for the U.S. federal government.

Engage with cutting-edge technologies in a dynamic environment.

Competitive salary range.

Supportive environment for career growth and professional development.

Apply via Haystack today!

Responsibilities

  • Design and develop reliable, modular, and secure software components
  • Develop software on a RHEL OS platform, including custom C++ and X windows-based applications, and web-based middleware
  • Write applications and policies for security accreditations
  • Maintain an active Secret Clearance and be able to obtain a Top Secret clearance
  • Travel up to 10% of the time for this on-site role

Qualifications

  • Bachelor's degree with nine years of experience, or Master's with seven years; additional experience accepted in lieu of a degree
  • Active Secret Clearance required to start; ability to obtain Top Secret clearance
  • Solid Linux (RHEL) familiarity and strong background in web technologies
  • Proficiency in JavaScript, React, CSS3, HTML5, and third-party libraries like jQuery and LESS
  • Industry experience in designing, building, and maintaining large-scale production systems
  • Understanding of low-level operating systems concepts including multi-threading, memory management, networking, and performance

Benefits

  • Opportunity to work on complex, mission-critical projects for the U.S. federal government
  • Engage with cutting-edge technologies in a dynamic environment
  • Supportive environment for career growth and professional development

Skills mentioned

C++LinuxJavaScriptReactCSSHTMLPerformance OptimizationMultithreadingTCP/IPApplication Security

About Haystack

Haystack combines AI & expert vetting to deliver world-class tech candidates who are engaged, aligned, and ready to interview. We're trusted by over 400,000+ tech candidates, working in Software Engineering, Data, Design, DevOps, Cloud, Tech Management, Testing, Product & Delivery, Architecture and more. 100s of employers from startups and scale-ups like Atom Bank, DuckDuckGo and Goodlord to established enterprises like American Express, Dunelm and AWS use Haystack to connect with qualified tech talent that they can't find anywhere else.

Technology51-200 employeesNewcastle upon Tyne, England