Principal Software Engineer - Full Stack (React, Next.js, Node.js, .Net)

Commonwealth Bank; Sydney; On-site; AUD 200,000 - 280,000; Full time

Job summary

Commonwealth Bank is seeking a Principal Software Engineer – Full Stack to drive AI-powered, scalable banking platforms. You’ll own end-to-end architecture across React, Next.js, Node.js, TypeScript and .NET, shaping cloud-native services and integration with AI-enabled capabilities.

You’ll mentor teams, lead large-scale modernization and collaborate across branches to deliver measurable improvements for customers and colleagues.

Qualifications

• Experience in designing end-to-end architectures for complex customer journeys.
• Strong breadth across front-end and back-end technologies.
• Proven track record shipping cloud-native distributed systems.
• Ability to translate business problems into technical options and architecture.

Responsibilities

• Shape the next generation of assisted technology and AI-powered services.
• Own health and direction of the broader technology landscape across teams.
• Mentor engineers and influence architectural direction across multiple squads.
• Lead safe, large-scale modernization of legacy environments.

Skills

React

Next.js

Node.js

TypeScript

.NET

Cloud

Education

Bachelor's degree in CS or equivalent

Tools

Express

AWS CDK

Terraform

GitHub Actions

AWS CloudFormation

Prometheus

Job description

Principal Software Engineer - Full Stack (React, Next.js, Node.js, .Net)

• We're transforming assisted banking through AI-powered, full-stack engineering at scale.
• You have Principal-level expertise across React, Next.js, Node.js, TypeScript, .NET and cloud.
• Together we will reimagine how branch colleagues serve customers with intelligent technology.

Do work that matters:

As a Principal Software Engineer – Full Stack, you’ll shape the next generation of assisted technology, modernising the platforms behind critical branch, customer and colleague experiences. This is a ground-up transformation where AI, agentic capabilities and LLM-powered services are part of the engineering strategy, not an afterthought. You’ll bring deep full-stack expertise across TypeScript, React, Next.js, Node.js, APIs, .NET and cloud to define architecture, simplify complexity and build modern services at scale.

You’ll operate with genuine technical and strategic ownership, looking beyond today’s requirements to anticipate what customers, colleagues and engineering teams will need next. You’ll uncover problems before they become problems, identify opportunities before they become requirements, and turn uncertainty into action. Customer obsessed and comfortable challenging convention, you’ll influence across teams, mentor engineers and own the health and direction of the broader technology landscape.

See yourself in our team:

You’ll join our Customer Service Network team, working within Assisted Technology to reimagine how our branch colleagues support customers. We’re bringing together engineering, customer journeys and colleague experiences to move beyond disconnected technology and create simpler, more connected ways to serve customers. Our team is building capabilities including intelligent concierge experiences, agentic appointment booking, customer-intent capture, skills matching and smarter branch operations, all with the ambition of helping colleagues serve customers faster and reducing the time customers spend waiting.

We’re a team that enjoys solving complex problems together and shaping solutions where the answers aren’t always obvious. With significant greenfield engineering ahead of us, you’ll work across TypeScript, Next.js, APIs, .NET and AI-enabled engineering, while helping influence our architecture, engineering practices and technical direction. You’ll have the space to challenge ideas, share your expertise and help us build experiences that make a meaningful difference for both our customers and the colleagues who serve them.

We’re interested in hearing from people who:

• Bring deep systems-thinking and end-to-end architecture experience, connecting complex customer journeys, platforms, data, dependencies and technical requirements across highly interconnected environments.
• Have genuine full-stack engineering breadth, ideally across TypeScript, React, Next.js and Node.js and has the ability to support legacy technologies where customer or business outcomes require it.
• Have designed and delivered cloud-native, distributed systems end to end, spanning APIs, event-driven architectures, SDKs, data, CI/CD, infrastructure as code, observability, resilience and complex integrations.
• Can turn ambiguous business and domain problems into clear technical options and architecture, making pragmatic product-first trade-offs and establishing technical direction across multiple engineering teams.
• Have led safe, large-scale modernisation of interconnected legacy environments, simplifying complexity and technical debt while protecting reliability, customer experience and delivery momentum through the transition.
• Bring strong integration engineering experience, particularly across complex APIs and capabilities such as authentication, identity, biometrics, NFC or hardware-to-software integration.
• Use AI-powered engineering and agentic tools practically across the software lifecycle, accelerating discovery, reverse engineering, requirements definition, development, testing, modernisation and delivery rather than treating AI as a standalone capability.
• Engineer for production from day one, applying secure-by-design principles, resilience patterns, performance optimisation, strong observability and operational ownership from discovery and build through deployment and ongoing optimisation.
• Demonstrate Principal Engineer-level technical leadership and influence, mentoring Staff, Senior and Software Engineers, constructively challenging decisions, raising design and engineering standards, and balancing hands-on technical credibility with long-term architectural stewardship.

We don't expect you to know everything, but experience in several of the following will set you up for success:

• Back-End Engineering: Node.js, Express, .NET Core C#, microservices, Web APIs
• Front-End Engineering: React, Next.js, TypeScript
• Databases & Data Engineering: Oracle PL/SQL, MongoDB, AWS NoSQL services, high-availability and performance-optimised data layers
• Cloud Engineering: AWS, cloud-native services, scalable and secure cloud infrastructure
• Infrastructure as Code (IaC): AWS CDK, Terraform, AWS CloudFormation
• DevSecOps & CI/CD: GitHub Actions, CI/CD pipelines, security automation, continuous delivery
• Quality Engineering & Test Automation: Unit testing, component testing, integration testing, end-to-end testing, Specmatic API contract testing
• Source Code & Repository Strategy: GitHub, advanced Git workflows, branching strategies, monorepo architecture, TurboRepo
• Observability & Site Reliability Engineering: Observe, Prometheus, Grafana, PagerDuty, monitoring, alerting, operational reliability

If you're already part of the Commonwealth Bank Group (including Bankwest, x15ventures), you'll need to apply through Sidekick to submit a valid application. We’re keen to support you with the next step in your career.

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