Principal Backend Engineer

Usmobile; Montreal (administrative region); On-site; CAD 100,000 - 140,000; Full time

Benefits offered by this job

Health care coverage

Flexible paid time off

Gym reimbursement

Free cell phone service

Equipment + Bose headphones

Job summary

US Mobile is hiring a backend engineer and hands-on architect to scale the platform connecting millions of devices to wireless networks. You will design scalable microservices, develop REST APIs, and drive performance tuning while integrating AI-assisted development tools to speed delivery.

The role emphasizes building reliable systems, collaborating with Product, QA, and DevOps teams, and deploying new features with high quality and uptime, supporting rapid growth and innovation.

Qualifications

• 10+ years of Java/Spring Boot experience.
• Proficiency in designing and consuming REST APIs.
• Experience with message brokers like RabbitMQ or AWS SQS/SNS.
• NoSQL experience with MongoDB.
• Experience integrating AI-assisted development tools like Claude and Opencode.
• Solid Git, CI/CD workflows and Agile practices.

Responsibilities

• Architect optimal backend solutions for business problems.
• Deploy new features and APIs.
• Scale systems to tens of millions of users and devices.
• Build tools and frameworks ensuring high quality products.
• Maintain uptime and reliability of services.
• Develop and maintain RESTful APIs in Java or Python; async messaging via RabbitMQ/AWS.
• Collaborate with Product, QA, and DevOps teams; implement tests and performance tuning.

Skills

Java

Spring Boot

REST APIs

RabbitMQ

AWS SQS/SNS

MongoDB

Claude

Opencode

Git

CI/CD

Agile

Debugging

Communication

Tools

Claude

Opencode

Job description

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.

• Architect optimal solutions to our business problems
• Deploy exciting new features
• Help us scale to scale to 10's of millions of customers & connected devices
• Build quality tools and frameworks to ensure a high-quality product
• Build systems to ensure continuous uptime

• 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 unit and integration tests
• Participate in system architecture design, code reviews, and performance tuning

• 10+ years of experience with Java and Spring Boot
• Strong experience with building and consuming REST APIs
• Hands-on experience with message brokers such as RabbitMQ or AWS SQS/SNS
• Familiarity with MongoDB or other NoSQL database technologies
• Experience 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 services.
• Demonstrated 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 efficiency.
• Solid understanding of Git, CI/CD workflows, and agile development practices
• Excellent debugging, problem-solving, and communication skills
• Excellent problem-solving and debugging skills
• Strong communication and team collaboration skills

• Health care coverage
• Flexible paid time off
• Gym reimbursement
• Free cell phone service
• Your choice of equipment + Bose QC/Apple Airpod Pro headphones