Full-Stack Software Engineer

US Mobile•Montreal, QC

1d•$120,000 - $150,000•Hybrid

About The Position

US Mobile is building the future of wireless communication with the goal of one unified network open to any person and any device, worldwide. They are empowering customers with all three major networks on one phone and one plan, plus home internet from Starlink, with no lock-in or commitments. They offer custom fit plans at every price point and 24/7 customer support with real people. The company values real-time feedback from customers to inform product roadmaps and has been recognized by Consumer Reports as the top-rated mobile carrier for two consecutive years. US Mobile is building innovative systems that scale with a network-agnostic tech stack and agile, cross-functional teams built on trust and mutual respect. They are looking for talented, ambitious, and entrepreneurial team members who are excited to tackle challenges in a fast-paced, flexible, and collaborative environment without compromising standards. This role specifically involves scaling and connecting millions of devices to wireless networks, offering incredible projects and potential impact.

Requirements

Strong full-stack engineer comfortable owning a feature from Postgres schema through WebSocket protocol to the React component the user clicks on.
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.
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.

Nice To Haves

Prior experience replacing or building support / messaging / chat tooling (Intercom, Zendesk, Front, LiveChat, etc.).
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.