Software Engineer Contractor Jobs in Houston, TX

Job#: 3040288
Job Description:
Software Engineer - Legacy Modernization & API Development
Team: Catalyst - Core Modernization & AI Engineering
Organization: Landmark Software & Services
Reports To: Director of Modernization & AI Systems
Level: Principal Software Developer (I3) or Technical Advisor (J1), based on experience
Location: Houston, TX (Hybrid)
Employment Type: Full-Time, Contract-to-Hire
Work Authorization: Candidates must be legally authorized to work in the United States.
Position Overview
We are seeking an experienced Software Engineer to help modernize legacy applications and transform them into scalable, maintainable software solutions. In this role, you will analyze existing codebases, understand legacy business logic, and rebuild critical functionality as modern, API-driven services. You will work closely with architects and senior engineers while leveraging AI-powered development tools to accelerate code analysis, testing, and modernization efforts.
Key Responsibilities

• Modernize legacy Windows and Fortran-based applications into modern, maintainable solutions.
• Design, develop, and support APIs that expose existing computational capabilities to modern platforms and consumers.
• Create characterization, regression, and automated tests to ensure modernized applications maintain expected functionality.
• Utilize AI-assisted development tools for code comprehension, translation, test generation, and productivity enhancement.
• Follow established modernization frameworks, architectural standards, and engineering best practices.
• Collaborate with architects, senior engineers, and business stakeholders to deliver high-quality software solutions.

Required Qualifications

• 7+ years of professional software engineering experience.
• Strong proficiency in at least one enterprise or systems programming language such as:
  • C++
  • C# / .NET
  • Java
• Experience working with APIs and service-oriented architectures.
• Demonstrated experience writing automated tests and validating behavior-sensitive code changes.
• Hands-on experience using AI coding assistants within software development workflows.
• Experience working in Agile environments and familiarity with emerging AI-enabled development methodologies, including Spec-Driven Development and AI Development Life Cycle (AIDLC).

Preferred Qualifications

• Exposure to Fortran or other legacy programming languages.
• Experience deploying applications in AWS and/or Azure environments.
• Familiarity with AI frameworks and orchestration tools such as:
  • LangChain
  • LangGraph
  • DeepAgents
• Experience working with scientific, engineering, or numerical software applications.

Success Factors
The ideal candidate will:

• Be an effective communicator who can clearly explain complex technical concepts and legacy system behaviors.
• Thrive in situations involving ambiguity, undocumented systems, and evolving requirements.
• Demonstrate strong analytical and problem-solving skills with an investigative mindset.
• Enjoy reverse-engineering and understanding complex legacy applications.
• Balance engineering rigor with practical delivery objectives.
• Collaborate effectively with technical teams and API consumers to deliver business value.

Everforth Apex is a world-class IT services company that serves thousands of clients across the globe. When you join Everforth 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 ClearlyRateds Best of Staffing in Talent Satisfaction in the United States and Great Place to Work in the United Kingdom and Mexico.
Everforth Apex uses a virtual recruiter as part of the application process. Click for more details. By applying for this job, you agree to receive calls, AI-generated calls, text messages, or emails from Everforth Apex and its affiliates, and contracted partners. Frequency varies for text messages. Message and data rates may apply. Carriers are not liable for delayed or undelivered messages. You can reply STOP to cancel and HELP for help. You can access our privacy policy at
Everforth Apex Benefits Overview: Everforth 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. Everforth 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, Everforth 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. Everforth 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 Everforth Apex team member can provide.
Everforth 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. Everforth Apex will consider qualified applicants with criminal histories in a manner consistent with the requirements of applicable law.
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