Principal Backend Engineer

US Mobile is building the future of wireless communication. The goal: one unified network open to any person and any device, worldwide. Connection without walls. We’re getting there by empowering customers. All three major networks on one phone and one plan, plus home internet from Starlink. No lock-in. No commitments. Custom fit plans at every price point. 24/7 customer support with real people, empowered to help. We get real-time feedback from Reddit, surveys, and customer support informing product roadmaps and everything we do. It’s working — Consumer Reports named us the top-rated mobile carrier two years in a row.* And we’re building innovative systems that scale. A network agnostic tech stack. Agile, cross-functional teams built on trust and mutual respect. This work isn’t for everyone. If you work fast, flexibly, and collaboratively — without compromising standards — we want to hear from you. We're looking for an exceptional backend engineer and hands-on architect to help us scale and connect millions of devices to wireless networks. The projects and potential impact are incredible. We're looking for talented, ambitious, and entrepreneurial team members who are excited to tackle these challenges. You will: Architect optimal solutions to our business problemsDeploy exciting new featuresHelp us scale to scale to 10’s of millions of customers & connected devicesBuild quality tools and frameworks to ensure a high-quality productBuild systems to ensure continuous uptime Responsibilities: Develop and maintain RESTful APIs using Java (Spring Boot or related web frameworks) or Python (Flask, Django)Design and implement asynchronous service communication using RabbitMQ or AWS SQS/SNSWork with NoSQL databases like MongoDB for data modeling and storageCollaborate with Product, QA, and DevOps teams to deliver reliable and scalable featuresWrite clean, testable, and well-documented code with unit and integration testsParticipate in system architecture design, code reviews, and performance tuning Qualifications: 10+ years of experience with Java and Spring BootStrong experience with building and consuming REST APIsHands-on experience with message brokers such as RabbitMQ or AWS SQS/SNSFamiliarity with MongoDB or other NoSQL database technologiesExperience integrating and leveraging AI-assisted development tools such as Claude and Opencode to accelerate backend development, including code generation, debugging, and optimization of APIs and servicesDemonstrated ability to incorporate AI tools into the software development lifecycle, using Claude or Opencode for tasks like automated code reviews, documentation generation, and improving system design efficiencySolid understanding of Git, CI/CD workflows, and agile development practicesExcellent debugging, problem-solving, and communication skillsExcellent problem-solving and debugging skillsStrong communication and team collaboration skills Benefits: Health care coverageFlexible paid time off Gym reimbursementFree cell phone serviceYour choice of equipment + Bose QC/Apple Airpod Pro headphones Think you're a good fit? Apply to learn more! We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses and identifying potential inconsistencies or verification signals in application materials based on available information. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.