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Applications Dev & Test - Software Design Engineer 4

Apex Systems Mountain View, California, United States

onsitefull-time
Posted Feb 24, 2026Apply by Mar 26, 2026

Role & seniority: Software Design Engineer 4 (senior-level, contract)

Stack/tools: Windows OS (3+ years), C/C++ (3+ years), kernel driver API familiarity; debugging with Windows Debugger, instrumentation-based analysis, WPP/ETW trace collection; OS-level/system software focus

Top 3 responsibilities

  • Analyze and modernize complex legacy implementations

  • Write clean, maintainable OS-/systems-level C/C++ code

  • Debug, fix issues with advanced OS-level tools; prepare specifications, test plans, migration packages; conduct unit testing and post-implementation validation

Must-have skills

  • 5+ years in systems-level engineering and software development

  • 3+ years Windows OS knowledge; C/C++ development

  • Kernel driver API familiarity; strong data structures/algorithms; ability to modernize legacy APIs

  • Proficiency with debugging and performance tools (Windows Debugger, instrumentation, WPP/ETW)

Nice-to-haves

  • Bachelor’s degree in CS/CE or related field

  • Deep Windows OS-level experience; strong debugging and performance analysis

  • Track record modernizing legacy systems/APIs

  • Location & work type: Onsite, Redmond, WA; 5-month contract (1/20/2026–6/30/2026)

Full Description

Job#: 3017685

Job Description

Software Design Engineer 4

Start Date: 1/20/2026

End Date: 6/30/2026

Duration: ~5 months

Location: Onsite – Redmond, WA

Openings: 1

Pay Range: $73–$78/hr

Top Must-Have Hard Skills

Operating Systems Knowledge (Windows preferred): 3+ years

C/C++ Development: 3+ years

Kernel Driver API Familiarity: Ability to rapidly gain understanding

Ideal Candidate Profile

Education: Bachelor’s degree in Computer Science, Computer Engineering, or related field.

Experience: 5+ years in systems-level engineering and software development.

Core Competencies

  • Strong foundation in data structures, algorithms, and software design.
  • Large-scale systems software design and troubleshooting.
  • Hands-on experience writing systems-level code in C and C++.
  • Proficiency with debugging tools and techniques, including Windows Debugger, instrumentation-based analysis, and WPP/ETW trace collection.
  • Ability to modernize legacy APIs and implement new designs.
  • Sufficient proficiency in reading/writing code.
  • Typical Day

Analyze and modernize complex legacy implementations. Write clean, maintainable systems-level code in C/C++. Debug and fix issues using advanced OS-level tools. Prepare detailed specifications, test plans, and migration packages. Conduct unit testing and post-implementation validation.

Ideal Candidate

Deep OS-level engineering experience with Windows. Strong debugging and performance analysis skills. Proven ability to modernize legacy systems and APIs.

EEO Employer

Apex Systems is an equal opportunity employer. We do not discriminate or allow discrimination on the basis of race, color, religion, creed, sex (including pregnancy, childbirth, breastfeeding, or related medical conditions), age, sexual orientation, gender identity, national origin, ancestry, citizenship, genetic information, registered domestic partner status, marital status, disability, status as a crime victim, protected veteran status, political affiliation, union membership, or any other characteristic protected by law. Apex will consider qualified applicants with criminal histories in a manner consistent with the requirements of applicable law. If you have visited our website in search of information on employment opportunities or to apply for a position, and you require an accommodation in using our website for a search or application, please contact our Employee Services Department at [email protected] or 844-463-6178.

Apex Systems is a world-class IT services company that serves thousands of clients across the globe. When you join Apex, you become part of a team that values innovation, collaboration, and continuous learning. We offer quality career resources, training, certifications, development opportunities, and a comprehensive benefits package. Our commitment to excellence is reflected in many awards, including ClearlyRated's Best of Staffing® in Talent Satisfaction in the United States and Great Place to Work® in the United Kingdom and Mexico. Apex uses a virtual recruiter as part of the application process. Click here for more details.

Apex Benefits Overview: Apex offers a range of supplemental benefits, including medical, dental, vision, life, disability, and other insurance plans that offer an optional layer of financial protection. We offer an ESPP (employee stock purchase program) and a 401K program which allows you to contribute typically within 30 days of starting, with a company match after 12 months of tenure. Apex also offers a HSA (Health Savings Account on the HDHP plan), a SupportLinc Employee Assistance Program (EAP) with up to 8 free counseling sessions, a corporate discount savings program and other discounts. In terms of professional development, Apex hosts an on-demand training program, provides access to certification prep and a library of technical and leadership courses/books/seminars once you have 6+ months of tenure, and certification discounts and other perks to associations that include CompTIA and IIBA. Apex has a dedicated customer service team for our Consultants that can address questions around benefits and other resources, as well as a certified Career Coach. You can access a full list of our benefits, programs, support teams and resources within our ‘Welcome Packet’ as well, which an Apex team member can provide.

Apex Systems is a world-class IT services company that serves thousands of clients across the globe. When you join Apex, you become part of a team that values innovation, collaboration, and continuous learning. We offer quality career resources, training, certifications, development opportunities, and a comprehensive benefits package. Our commitment to excellence is reflected in many awards, including ClearlyRated's Best of Staffing® in Talent Satisfaction in the United States and Great Place to Work® in the United Kingdom and Mexico. Apex uses a virtual recruiter as part of the application process. Click here for more details.

Apex Benefits Overview: Apex offers a range of supplemental benefits, including medical, dental, vision, life, disability, and other insurance plans that offer an optional layer of financial protection. We offer an ESPP (employee stock purchase program) and a 401K program which allows you to contribute typically within 30 days of starting, with a company match after 12 months of tenure. Apex also offers a HSA (Health Savings Account on the HDHP plan), a SupportLinc Employee Assistance Program (EAP) with up to 8 free counseling sessions, a corporate discount savings program and other discounts. In terms of professional development, Apex hosts an on-demand training program, provides access to certification prep and a library of technical and leadership courses/books/seminars once you have 6+ months of tenure, and certification discounts and other perks to associations that include CompTIA and IIBA. Apex has a dedicated customer service team for our Consultants that can address questions around benefits and other resources, as well as a certified Career Coach. You can access a full list of our benefits, programs, support teams and resources within our ‘Welcome Packet’ as well, which an Apex team member can provide.

Apex Systems is part of the Commercial Segment of ASGN Incorporated.

NYSE: ASGN

4400 Cox Road

Suite 200

Glen Allen, Virginia 23060

Apex Systems is an equal opportunity employer. We do not discriminate or allow discrimination on the basis of race, color, religion, creed, sex (including pregnancy, childbirth, breastfeeding, or related medical conditions), age, sexual orientation, gender identity, national origin, ancestry, citizenship, genetic information, registered domestic partner status, marital status, disability, status as a crime victim, protected veteran status, political affiliation, union membership, or any other characteristic protected by law. Apex will consider qualified applicants with criminal histories in a manner consistent with the requirements of applicable law. If you have visited our website in search of information on employment opportunities or to apply for a position, and you require an accommodation in using our website for a search or application, please contact our Benefits Department at [email protected] or 804-523-8228. (Do not submit resumes or solicit consultants to this email address). UnitedHealthcare creates and publishes the Transparency in Coverage Machine-Readable Files on behalf of Apex Systems.

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