Modern Technology Solutions, INC. (MTSI) is seeking a highly motivated and experienced Senior Application Developer to join our dynamic team. The ideal candidate will have extensive experience working with best-in-class business applications such as  ServiceNow ,  Salesforce , and  Smartsheet , with strong expertise in  API integrations and modern data management frameworks like Data Lakes and Databricks . This role is critical in driving innovation, enabling seamless integrations, and supporting the development of a robust digital ecosystem to enhance business operations. Key Responsibilities: Application Development & Customization: Design, develop, and implement scalable solutions for enterprise applications, including ServiceNow, Salesforce, and Smartsheet, while ensuring alignment with business objectives. API Development & Integration: Build, maintain, and optimize APIs to ensure seamless connectivity between enterprise applications, SaaS platforms (e.g., Smartsheet), and custom-built solutions. Strong understanding of DevSecOps principles with hands-on experience in version control, secure CI/CD pipelines, automated testing, vulnerability scanning, and artifact management within regulated environments. Data Management Expertise: Collaborate on data initiatives leveraging Data Lakes or Databricks environments for storage optimization, real-time access, and integration workflows. Smartsheet Customization & Automation: Create and manage advanced Smartsheet workflows and integrations to support project management, team collaboration, and process automation. Technical Leadership: Provide thought leadership in application development best practices and serve as a technical advisor to junior developers and cross-functional teams. Collaboration, communication, and mentoring skills are critical. Problem Solving: Diagnose complex application issues and deliver efficient solutions while improving overall system reliability and performance. Quality & Compliance: Ensure applications and integrations comply with organizational security policies, data privacy standards, and industry best practices. Familiarity with developing within a DoD environment, particularly within Azure GovCloud and NIST 800-218 Documentation & Collaboration: Maintain robust documentation and effectively collaborate with teams across engineering, data science, and business operations disciplines. Qualifications: Must be a U.S. citizen Education: Bachelor’s degree in Computer Science, Software Engineering, Information Systems, or a related field (Master’s preferred). Professional Experience : Minimum 8+ years of application development experience. Proven track record working with enterprise-grade applications such as ServiceNow, Salesforce, and Smartsheet. Technical Skills : Advanced understanding of API lifecycle management, including creation, integration, troubleshooting, and performance optimization. Experience with Data Lakes and Databricks for real-time data processing and scalable storage solutions. Expertise in Smartsheet functionality, including advanced automation, reporting, and dashboard development. Experience with JavaScript for application development and customization. Proficiency in programming languages such as Java, C#, Python, or other relevant frameworks. Strong knowledge of modern development methodologies such as Agile and DevSecOps. Familiarity with cloud-based platforms such as AWS, Azure, or GCP. #LI-KK1