Full-Stack Software Engineer at USMobile – Montreal | Jobyssey

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 a full-stack JS engineer 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.

As a Full-Stack Software Engineer, you will:

Work on developing and deploying exciting new features
Advise on technologies and present solutions to the team
Take on legacy architecture and digital transformation projects
Expand on our Node services suite of applications
Document any new and undocumented processes and workflows
Work in a start-up environment with lots to do and lots of hats to wear
Assist in building tools to ensure a high-quality end-user product
Help us scale to 10’s of millions of customers & connected devices

What we are looking for:

Strong full-stack engineer comfortable owning a feature from Postgres schema through WebSocket protocol to the React component the user clicks on.
Prior experience replacing or building support / messaging / chat tooling (Intercom, Zendesk, Front, LiveChat, etc.).
Deep Node.js + TypeScript experience. Strict TS, generics, discriminated unions — you reach for the type system before you reach for tests.
Strong React. Modern hooks-era React; you've shipped non-trivial SPAs and know how to keep them fast under real load. Bonus if you've worked with React Native (especially native module / push / deep-link plumbing) or built embeddable / drop-in components.
Experience with relational data modeling and SQL (Postgres preferred). You know what an index does and when it doesn't.
Comfort with real-time systems — WebSockets, pub/sub, presence, reconnection, backpressure. You understand why at-least-once delivery is a different problem from exactly-once.
Experience with queues and async fan-out (SQS, RabbitMQ, Kafka, Redis Streams).
Working knowledge of AWS and containerized deployments (EKS / Kubernetes, or equivalent). You don't need to be an SRE, but you should be able to read a Terraform plan and know what an ALB is doing.
Solid API design instincts — REST contracts, versioning, OpenAPI / typed clients, idempotency, pagination.
Care about security and compliance. You'd push back if someone proposed logging message bodies to CloudWatch.
A bias toward clean, appropriately tested code and clear written communication — specs, ADRs, PR descriptions that explain the why.
Strong communication and writing — most of our coordination is async and in-doc.
An ability and desire to help teammates grow through mentorship and code review.

Bonus Points:

Experience with React Native beyond the JS surface — bridging modules, push tokens, background state, keyboard / safe-area edge cases.
Experience designing or operating systems with CPNI / HIPAA / PCI / SOC 2 compliance constraints.
Experience with SSO / OIDC (Okta especially) and JWT-based session models that span multiple clients.
Experience operating WebSocket fleets at scale — sticky sessions, horizontal scaling, graceful reconnect.
Familiarity with Nx, pnpm workspaces, or comparable monorepo tooling.
OpenAPI-first development, zod, Vitest, Playwright, Testcontainers, k6.
Comfort writing or reading Terraform.

Think you're a good fit? Applied to learn more!

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As a Full-Stack Software Engineer, you will:

What we are looking for:

Bonus Points: