Senior Software Engineer | Full Stack .NET & React | Sydney (On-site)

Big Wave Digital; Sydney; On-site; AUD 120,000 - 180,000; Full time

Job summary

Big Wave Digital is seeking a Senior Software Engineer for a financial services client to own the customer acquisition journey—from first visit to active customer. You’ll build across the stack with React, TypeScript, and .NET, shaping the experience and driving growth.

Location is Sydney, NSW, on-site. The role emphasizes ownership, collaboration with design, product, and compliance, and delivering reliable, accessible customer experiences at scale.

Qualifications

• Full-stack engineering experience with .NET and frontend in React/TypeScript.
• Experience with relational databases and headless CMS.
• Clear, testable code and attention to edge cases.
• Ownership mindset and ability to adapt priorities.

Responsibilities

• Build customer-facing features in React and TypeScript, and APIs in .NET.
• Improve onboarding, SSO, and data collection rules.
• Own features from design through release and improvements.
• Collaborate with design, product, compliance, and other engineers.

Skills

Full-stack engineering

NET

React

TypeScript

Relational databases

Headless CMS

Clear, testable code

Edge cases

Ownership

Tools

.NET

React

TypeScript

OAuth/OIDC

SAML

Job description

Build the first experience customers have with a financial platform.

We’re recruiting a Senior Software Engineer for a financial services client’s customer acquisition team. You’ll work on the journey from someone’s first visit to becoming an active customer: the public website, onboarding, identity verification, sign-in and promotions.

This is a hands-on role with real ownership. You’ll build across the stack, help shape technical decisions and see how your work affects customer experience and growth.

What you’ll do

• Build customer-facing features in React and TypeScript, alongside APIs and services in .NET.
• Improve onboarding, SSO and the systems that determine what information each customer needs to provide.
• Own features from design discussions through release and ongoing improvement.
• Work closely with design, product, compliance and other engineers.
• Keep performance, reliability, accessibility and maintainability front of mind.

What you’ll bring

• Strong full-stack engineering experience, with solid .NET skills and confidence building frontend products in React and TypeScript.
• Experience with relational databases, data-driven rules and headless CMS platforms.
• An eye for edge cases and a habit of writing clear, testable code.
• Curiosity about how technical decisions affect conversion and the customer experience.
• The confidence to take ownership while priorities evolve.

Experience with OAuth/OIDC or SAML, KYC integrations, multilingual websites, technical SEO or high-conversion digital products would be a bonus.

The details

• Location: Sydney, NSW (on-site)
• Seniority: Mid-Senior level
• Employment type: Full-time

If you like building polished customer experiences and enjoy solving the engineering challenges behind them, I’d love to hear from you.