Software Engineer

Apex Systems; Houston (TX); Hybrid; USD 140,000 - 190,000; Full time

Benefits offered by this job

Health insurance

401K with company match

ESPP

HSA

Employee Assistance Program (EAP)

Discount programs

Job summary

Everforth Apex is seeking a Principal Software Developer or Technical Advisor to lead legacy modernization and API development efforts in a hybrid Houston setting. You will modernize legacy Windows and Fortran code, design robust APIs, and ensure quality through automated tests, with AI-assisted tooling guiding development.

The role requires 7+ years in software engineering, strong programming plus API/SOA experience, and familiarity with Agile and AI-enabled development life cycles.

Qualifications

• 7+ years of professional software engineering experience.
• Proficiency in C++, C#/.NET or Java with API/SOA experience.
• Experience writing automated tests and validating behavior-sensitive changes.
• Hands-on experience using AI coding assistants in development workflows.
• Familiarity with Agile environments and AI-enabled development methods (AIDLC).

Responsibilities

• Modernize legacy Windows and Fortran-based applications into modern, maintainable solutions.
• Design, develop, and support APIs exposing existing capabilities to modern platforms.
• Create characterization, regression, and automated tests to ensure functionality remains intact.
• Use AI-assisted development tools to improve code comprehension, testing, and productivity.
• Follow modernization frameworks, architectural standards, and engineering best practices.
• Collaborate with architects, senior engineers, and stakeholders to deliver high-quality software.

Skills

Software engineering

C++

C#/NET

Java

APIs/SOA

Automated tests

AI coding assistants

Agile AI lifecycle

Tools

Fortran

AWS

Azure

LangChain

LangGraph

DeepAgents

Job description

Position Overview

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.

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# / .NETJavaExperience 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:LangChainLangGraphDeepAgents
• Experience working with scientific, engineering, or numerical software applications.

Success Factors

• 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.

Company Culture & Benefits

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 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.

EEO and Accessibility Statement

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.

If you require an accommodation under the Americans with Disabilities Act to participate in an interview with a virtual recruiter or to use our website for a search or application, please contact our Benefits Department at [e-mail] or 804-523-8228. Please note that this contact information is strictly to be used for medical ADA accommodations and that no other inquiries will be answered.

UnitedHealthcare creates and publishes the Transparency in Coverage Machine-Readable Files on behalf of Everforth Apex Systems.