Senior Backend Engineer (Online Security)

US Mobile is on a mission to revolutionize connectivity. Imagine a world where you can go into a single app and buy terabytes of data for every one of your devices: phone, smart devices, car, home broadband, and more. That’s the future that US Mobile is building: a software platform built truly for the 21st century and the age of 5G and IoT, with world class engineering, best-in-class user experience, and features that will define the next generation of connectivity. 

At the core of it all, we have a team and culture that has been recognized by Forbes as one of the top 500 best startup employers in the US. Our team spans diverse backgrounds, cultures, and stories, with employees coming from 20+ countries.

We're a venture-backed company entering hypergrowth, having recently ranked 94th on Inc 5000's fastest-growing private companies in America, and we’re looking for someone exceptional to join our team.

We’re looking for a skilled and motivated Senior Backend Engineer to help us scale connectivity to millions of devices, while keeping that platform secure from the ground up. In this role, you’ll design, develop, and maintain scalable backend services and APIs that power our products, with deep ownership over online security: protecting devices and networks, hardening authentication and access controls, and building systems that detect and respond to threats in real time.

You’ll work in a collaborative, agile environment and contribute to mission-critical systems that millions of users depend on every day.

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/SNS

Work with NoSQL databases like MongoDB for data modeling and storage

Collaborate with Product, QA, and DevOps teams to deliver reliable and scalable features

Write clean, testable, and well-documented code with comprehensive unit and integration tests

Participate in system architecture design, code reviews, and performance tuning

7+ years of experience with Java and Spring Boot

Strong experience within Online Security, including:

Protecting internet-connected devices, networks, and personal data from digital threats

Authentication and Access management

Software Protection

Network Security

Threat Detection

Strong experience building and consuming REST APIs at scale

Hands-on experience with message brokers such as RabbitMQ or AWS SQS/SNS

Familiarity with MongoDB or other NoSQL database technologies

Solid understanding of Git, CI/CD workflows, and agile development practices

Excellent debugging, problem-solving, and communication skills

Strong team collaboration instincts, you make the people around you better