Application Developer II

McCarthy Holdings, Inc. (McCarthy) , is the holding entity for McCarthy Building Companies, Inc., the oldest privately-held national construction company in America, and Castle Contracting. McCarthy provides the crucial business infrastructure for these entities and connects the day-to-day operations to ensure seamless operations across the business. Repeatedly honored as a great place to work and healthiest employer, McCarthy is a 100 percent employee-owned company .

At McCarthy, we are committed to sustaining a culture that delivers great experiences for everyone. This begins with developing high-performing individuals and teams through our award-winning learning and development programs, best-in-class Total Rewards benefits, and our inclusive culture aligned with our core values: Genuine . We, Not I . All In.

How do McCarthy partners define our culture?

• We Live Our Core Values: We do whatever it takes to deliver on our promises with honesty and integrity.
• We are Employee Owned: We are personally invested in building the things people need in our communities.
• We Feel Like a Family: We value genuine connections and help each other succeed in an inclusive environment.
• We are Builders: We respect the work we do and everyone who helps make it happen safely.

Position Summary

McCarthy is seeking a full-time Application Developer located in St. Lous, MO who as part of the Enterprise Solutions and Analytics team, will play a crucial role in building our application and integration portfolio, supporting our existing systems and driving innovation following modern DevSecOps practices.

Key Responsibilities

Solution Design and Development

• Design and develop integration solutions by applying best practices and standard patterns in data model design, data transfer and event-based processing. Leverage integration capabilities such as Rest APIs, message queues and remote process execution in developing solutions. Implement solutions that process both structured and unstructured data (images, videos, model files etc.).
• Design and develop custom applications on AI platform Palantir, integrating them into McCarthy’s ecosystem of applications.
• Develop solutions for maximum reusability, using components available in enterprise applications and platforms. Promote modular approach in solution design and development. Maintain a robust integration application and integration environment to promote long-term flexibility and growth.
• Support the procurement of new applications and platforms by evaluating technical capabilities and providing insight.

Support and Administration

• Provide technical support and guidance for efficient and effective resolution of issues. Respond to queries from application teams in a timely manner to reduce disruption to end users.

Security

• Ensure integration and application solutions follow McCarthy’s security practices and guidelines.
• Enforce input validation and output encoding, avoid hardcoded secrets and credentials, apply least privilege logic in API and service interactions, use strong modern cryptography, sanitize logs, and perform threat modeling early and regularly.
• Adhere to and promote a shift-left security mindset for pipeline, secrets management and supply chain functions.

Project Execution, Task Management

• Follow best practices and support organizational effort in managing projects and tasks effectively. Demonstrate an agile mindset in planning and execution of tasks.

Continuous Learning and Improvement

• Constantly seek to improve current solutions. Identify opportunities to improve performance, automate workflows and improve end-user experience.
• Keep up with the latest on tools and platforms by attending vendor events and leveraging learning opportunities.

Internal Relationship Management

• Develop strong partnerships with internal IT staff to ensure solutions address McCarthy’s needs effectively and requests are addressed in a timely and effective manner. Work closely with business system analysts and product owners in understanding requirements and building solutions that implement user stories effectively.

Qualifications

• Minimum 5 years of experience with an enterprise iPaas (integration platform as a service) such as Boomi, Mulesoft or Snaplogic. Boomi experience would be preferable.
• Strong knowledge of database capabilities and API-driven integration frameworks. Strong knowledge of SQL. Solid understanding of data formats including JSON and XML.
• Experience developing solutions on an AI platform such as Palantir is a plus.
• 3 – 5 years of application development experience on a modern stack (e.g., .NET 6+/C#, Node.js/TypeScript, Python, Ruby — Ruby on Rails/Sinatra/ActiveRecord) building RESTful services, event-driven components, and CI/CD-backed deployments; familiarity with containers and cloud services is a plus.
• Working knowledge of DevSecOps practices and tools (DAST/SAST/SCA/secrets scanning) and severity-based remediation workflows in CI/CD. Examples of tools include Checkmarx, OWASP, GitHub, Snyk, Terrasan and Terraform
• Practical experience with secure file transfer (SFTP), key management, and PGP encryption in automated pipelines.
• Knowledge of cloud platforms such as AWS, Azure and Microsoft Office 365.
• Experience working on projects using an Agile approach and the Scrum framework.
• Constant learner with a passion for continuous growth and improvement.
• Strong interpersonal and communication skills. Strong team player with a collaborative mindset.

McCarthy is proud to be an equal opportunity employer, including disability and protected veteran status.

NOTICE TO EXTERNAL SEARCH FIRMS: McCarthy’s Talent Acquisition Team is the only authorized representative permitted to engage with external search firms, staffing agencies, or other third-party recruiting partners. McCarthy maintains an Approved Agency List for recruiting partners, which is reviewed and updated annually. McCarthy will only consider submissions from agencies with a signed fee agreement in place for the current year. McCarthy does not accept unsolicited resumes, candidate submissions, or referrals from agencies that do not meet these requirements. If a candidate is submitted without an active agreement, McCarthy will have no obligation to pay any fees and reserves the right to contact, engage, interview, or hire such candidate(s) without any financial or other responsibility to the submitting agency. Unsolicited resumes, including those sent directly to hiring managers or other employees, will be considered the property of McCarthy.