Full-Stack Backend Engineer

About Us At Express Marketing Solutions, we are a marketing company located in the heart of Torrance. As we expand our company, we are looking for a Full-Stack Backend Engineer to join our Team. This role will support the development of a new technology platform that is currently in its early stages and managed under our marketing company. Job Overview In this role, you’ll be assisting in designing, building, and maintaining the APIs that power our AI Voice Agent application. You’ll ensure that our API layer is secure, scalable, and well-documented, while reviewing and merging code contributions from contractors to maintain a consistent, production-ready codebase. This role is ideal for someone with backend experience, excellent attention to detail, and a passion for building reliable, high-performing systems. Job Duties and Responsibilities • Build and maintain standardized API endpoints for speech-to-text, text-to-speech, LLM, and related AI services. • Configure API Gateway rules for authentication, throttling, and access control. • Implement secure key management with temporary and restricted vendor access. • Ensure sensitive data protection using anonymization or test-data substitution. • Develop and maintain unit, integration, and contract testing frameworks. • Review, test, and merge contractor code to ensure performance, maintainability, and reliability. • Collaborate with AI/ML engineers, frontend developers, and vendors to align API needs. Job Requirements • Proficiency in backend development with Node.js/Express, Python/FastAPI, or similar. • Experience with API design, versioning, and documentation. • Familiarity with API Gateway and reverse proxy tools (Kong, NGINX, AWS API Gateway, etc.). • Understanding of security best practices (OAuth2, JWT, key management, data privacy). • Experience with testing frameworks (unit, integration, contract). • Skilled in Git workflows and CI/CD pipelines for multi-contributor projects. Compensation & Benefits • 25-30/hr • 100% employer paid health, dental, and vision insurance • 401K + employer 3% contribution • $50/month gym reimbursement • Paid time off and sick leave • Professional development and growth opportunities • Snack and refreshments in the office Why Join Our Team? At Express Marketing Solutions, we believe in building more than just products we’re building a community of innovators who want to shape the future of AI-powered communication. Our team is collaborative, fast-paced, and growth-oriented, with opportunities for career advancement and leadership. We’re committed to creating an environment where your work directly impacts the scalability, reliability, and trustworthiness of our platform. If you’re ambitious, self-motivated, and ready to work on cutting-edge technology with a supportive team, you’ll thrive here. We're an Equal Opportunity Employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. Job Type: Full-time Pay: $25.00 - $30.00 per hour Application Question(s): • Will you need a H-1B visa sponsorship now or in the future? Experience: • Back-end development: 2 years (Required) Work Location: In person