Spring is almost here. 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 looking for 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, improve performance and help shape the engineering standards behind a platform where speed, reliability, conversion and user experience genuinely matter.

What you’ll be doing

- 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’re looking for

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
- Positive 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 environment where priorities can move quickly




- Commercial curiosity and an understanding that great engineering can directly drive revenue and customer growth

Nice to have

Any of the following would be a bonus:

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

Why this one?

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 prospect to influence architecture, engineering quality and technical direction while still remaining hands-on.

The business is growing, the product is evolving quickly and there’s plenty left to build.

The offer

$180,000 base + superannuation + bonus

Package up to approximately $200,000

Sydney CBD

5 days per week onsite

Permanent position

High-impact customer-facing product

Fast-moving fintech environment

Strong senior engineering ownership

Please note: this position is Sydney-based and requires full Australian working rights. Sponsorship is not available.

If you’re a strong C#/.NET + React engineer who enjoys building products people actually use, this could be a very good way to head into spring.

Sydney CBD | 5 days onsite

$180,000 base + super + bonus | Package up to circa $200K

Permanent | No sponsorship available

📌 Senior Software Engineer | C#/.NET + React | FinTech / Crypto / FX - pckg. (Sydney)
🏢 Big Wave Digital
📍 Sydney