Principal Software Development Engineer in Test

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 hyper‑growth, 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.

US Mobile is looking for a Principal‑level SDET to own and elevate our quality engineering practice. This is a technical leadership role for someone who has built, scaled, and stabilized automated test platforms in modern microservices environments.

You’ll lead by example, designing test strategy, improving CI pipelines, mentoring engineers, and ensuring quality is embedded across the SDLC.

Technical Leadership

Own test architecture and automation strategy across backend and frontend systems

Design, build, and maintain scalable automated test frameworks

Lead end‑to‑end, API, integration, and UI automation

Drive adoption of best‑in‑class testing practices

Hands‑on Execution

Build and maintain pipelines using Selenium, Playwright or Cypress. (Currently using Cypress)

API testing

Improve test stability, performance, and execution time in CI / CD.

Actively debug flaky tests and CI failures

Platform & System Focus

Test Java / Spring Boot microservices

Validate async workflows (RabbitMQ)

Test data persistence layers (MongoDB)

Ensure quality in AWS‑based distributed systems

Partner with DevOps to improve pipelines and observability

Mentorship & Influence

Mentor Software Engineers on test design and automation

Establish coding standards and review practices for test code

Influence product and engineering leaders on quality risk and release readiness

Must Have

5+ years in Quality Engineering / Test Automation

Senior or Staff‑level experience in a product‑driven org

Deep expertise with Selenium, Playwright, Cypress

Strong Java background (writing production‑quality test code)

Experience testing microservices & distributed systems

CI / CD experience (GitHub Actions, Jenkins, GitLab, etc.)

Strong Linux fundamentals

Proven ability to lead and influence

Strong Plus

Contract testing (Pact or similar)

Performance testing experience

Cloud‑native testing in AWS

Observability‑driven testing (logs, metrics, traces)

Prior experience building QA orgs from messy to mature

Benefits

Competitive salary

Flexible working hours

Supplemental health insurance

Professional development stipend

$500 wfh tech set‑up reimbursement

Think you could be 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. 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.

#J-18808-Ljbffr