Senior Software Engineer | C#/.NET + React | Sydney CBD | $180K–$200K Package

This Senior Software Engineer role in Sydney CBD is a full-stack C#/.NET and React opportunity paying a $180K–$200K package. Spring is almost here, so maybe it’s time to warm up your career too.

We’re working with a fast-growing fintech exchange operating across crypto and FX, building high-performance digital products used by customers across multiple markets.

They’re after a Senior Software Engineer who can genuinely work across the stack: strong C#/.NET engineering on the backend, coupled with hands-on React and TypeScript capability on the frontend. This isn’t a backend role where you occasionally tweak a React component. You’ll own customer-facing features end-to-end, contribute to architecture, and help shape the engineering standards behind a platform where speed, reliability, conversion and user experience genuinely matter.

This Senior Software Engineer role in Sydney CBD is a full-stack C#/.NET and React opportunity paying a $180K–$200K package. Spring is almost here, so maybe it’s time to warm up your career too.

We’re working with a fast-growing fintech exchange operating across crypto and FX, building high-performance digital products used by customers across multiple markets.

They’re after a Senior Software Engineer who can genuinely work across the stack: strong C#/.NET engineering on the backend, coupled with hands-on React and TypeScript capability on the frontend. This isn’t a backend role where you occasionally tweak a React component. You’ll own customer-facing features end-to-end, contribute to architecture, and help shape the engineering standards behind a platform where speed, reliability,



conversion and user experience genuinely matter.

What you’ll be doing as a Senior Software Engineer

- Build and maintain features across the customer-facing product including the website, onboarding, account creation, promotions and authentication journeys
- Develop backend APIs and services using C# / .NET
- Build modern frontend experiences using React.js and TypeScript
- Take ownership of features from solution design through development, release and production support
- Contribute to architectural decisions and technical direction within the engineering squad
- Write clean, readable, testable and maintainable code
- Set a high standard through thoughtful code reviews and engineering best practice
- Improve frontend performance, accessibility, SEO and overall customer experience
- Build and maintain multi-region and multi-language product experiences
- Work with internationalisation and localisation including i18n, l10n and routing strategies
- Identify and resolve performance, reliability and quality issues before they become problems
- Work closely with product, marketing and commercial teams on technology that directly influences customer acquisition and growth

What we look for in a Senior Software Engineer





You’re likely an experienced Senior Full Stack Engineer who is comfortable taking responsibility rather than waiting for perfectly defined tickets. You’ll bring:

- Strong commercial C# / .NET backend engineering experience
- Solid hands-on React.js / TypeScript development capability
- Experience building and shipping customer-facing digital products
- Strong API and service development experience
- Experience with headless CMS and content-driven architectures
- Understanding of scalable, maintainable frontend architecture
- Experience building multi-region / multi-lingual products
- Knowledge of i18n and l10n
- Strong understanding of technical SEO including crawlability, structured data and Core Web Vitals
- Good engineering instincts around edge cases, failure modes, testing and maintainability
- An eye for frontend quality, usability and conversion, not simply whether something technically works
- A genuine ownership mentality: you care what happens after the code reaches production
- Confidence working in an workplace where priorities can move quickly

Nice to have

- Fintech, crypto, FX, trading or exchange experience
- Experience with high-conversion consumer or e-commerce products
- Customer onboarding or identity verification flows, including KYC
- SSO and authentication technologies including OAuth 2.0, OIDC or SAML
- Strong frontend performance knowledge including Lighthouse, accessibility and cross-device optimisation

Why this Senior Software Engineer role

This is a senior engineering role with real product ownership. You’ll be working on technology sitting directly between the business and its customers, rather than disappearing into an internal platform team three layers removed from the product. You’ll have the op

📌 Senior Software Engineer | C#/.NET + React | Sydney CBD | $180K–$200K Package
🏢 Big Wave Digital
📍 Sydney