Senior Full-Stack Integration Engineer
Location: Remote – United States
Experience: 5+ years of professional software engineering experience
We are seeking a Senior Full-Stack Integration Engineer to design, build, and support cloud-based applications, APIs, and external partner integrations. This position is best suited for a backend-leaning full-stack engineer with strong experience in Node.js, TypeScript, React, AWS, and production database environments.
The ideal candidate will have hands-on experience developing partner-facing APIs, integrating third-party systems, and building reliable cloud services used by external customers and business partners.
Responsibilities
Design, develop, test, and maintain backend services using Node.js and TypeScript
Build and enhance frontend application features using React and TypeScript
Design and develop REST and/or GraphQL APIs for use by external partners
Integrate applications with third-party platforms, vendors, and partner systems
Build and operate cloud-based services within AWS
Develop serverless applications using services such as AWS Lambda and API Gateway
Design and maintain production data models using relational or document databases
Collaborate with product, engineering, and external partner teams to define integration requirements
Troubleshoot API, data, and integration issues across distributed systems
Participate in code reviews, testing, deployment, and ongoing application support
Help establish scalable development practices for partner integrations and cloud services
Required Qualifications
5+ years of professional software engineering experience
Strong backend development experience with Node.js
Advanced TypeScript experience across backend and frontend applications
Professional frontend development experience using React
Production experience with a relational or document database, preferably PostgreSQL or MongoDB
Experience building and operating applications or services within AWS
Hands-on experience integrating with third-party or external partner systems
Experience designing and developing externally consumed REST and/or GraphQL APIs
Strong understanding of API security, authentication, error handling, and data validation
Ability to work effectively in a remote, collaborative engineering environment
Preferred Qualifications
Experience with NestJS
Production experience with MongoDB
Experience developing GraphQL APIs
Experience with AWS serverless technologies, including Lambda and API Gateway
Previous government or public-sector delivery experience
Experience supporting applications with multiple external partner integrations
Familiarity with automated testing, CI/CD pipelines, monitoring, and production support
This is a remote opportunity available to candidates located within the United States.
System One, and its subsidiaries including Joulé and Mountain Ltd., are leaders in delivering outsourced services and workforce solutions across North America. We help clients get work done more efficiently and economically, without compromising quality. System One not only serves as a valued partner for our clients, but we offer eligible employees health and welfare benefits coverage options including medical, dental, vision, spending accounts, life insurance, voluntary plans, as well as participation in a 401(k) plan.
System One is an Equal Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex (including pregnancy, childbirth, or related medical conditions), sexual orientation, gender identity, age, national origin, disability, family care or medical leave status, genetic information, veteran status, marital status, or any other characteristic protected by applicable federal, state, or local law.
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