Sydney | Fintech | .NET, React/TypeScript

This is not a standard .NET role. The team owns the entire front door of a global fintech product: the public website, onboarding, identity, and the promotions engine that brings customers in. Every millisecond of load time and every step in the signup flow has a measurable line to revenue. If you like engineering problems where the stakes are visible, read on.

The technical landscape

Headless CMS at scale. The public web surface runs on a content-driven architecture serving multiple regions and languages. You'll work on the patterns that keep it fast and maintainable: content modelling, edge caching and invalidation strategies, preview environments, and the discipline of keeping presentation cleanly decoupled from content so marketing can ship without engineering becoming a bottleneck.

Identity and SSO. You'll build and maintain the authentication layer that every customer passes through, including OAuth 2.0, OIDC and SAML integrations, session management, and the security posture that a regulated fintech demands. Identity here is not a solved problem sitting in a library; it's an active engineering surface with real trade-offs between security, conversion, and user experience.

Internationalisation done properly. Multi-region routing strategies, locale-aware rendering, i18n/l10n pipelines, and the infrastructure decisions that make a single codebase serve many markets without forking. If you've felt the pain of retrofitting i18n, you'll appreciate a team that treats it as an architectural concern from the start.

SEO as an engineering discipline. Structured data, crawlability, rendering strategy, and Core Web Vitals as a ranking factor. On an acquisition surface, technical SEO is performance engineering with commercial consequences, and you'll own it at depth.

The stack. Backend APIs and services in .NET.



Frontend product work in React and TypeScript. You're genuinely comfortable at both ends and you take ownership of what you ship, from shaping the solution through to production and what happens after.

What you'll do

- Build and evolve the website, onboarding flows, SSO, and acquisition promotions end-to-end
- Contribute to architectural decisions and technical direction within the squad
- Hold a high bar on code quality, performance, and reliability, in your own work and in review
- Work closely with the Product Owner, UX Designer, and fellow engineers to ship experiences that convert and feel right

What we're looking for

- Strong full-stack capability: solid .NET backend experience plus confident React/TypeScript product work
- Hands-on headless CMS experience and an understanding of what keeps content-driven architectures performant
- Multi-region, multi-lingual development experience: i18n, l10n, routing, and the complexity they bring
- Deep technical SEO fundamentals
- A track record of shipping quality software in a product setting with real users
- Good engineering instincts: edge cases, failure modes, and maintainability as a matter of course

Nice to have

- Onboarding, identity verification, or KYC flows
- Depth in frontend performance: Lighthouse, accessibility, cross-device behaviour
- Background in fintech, e-commerce, or other high-conversion consumer products

Why this role This surfaces are where engineering quality is most visible. Ship something faster, and conversion moves. Get identity right, and thousands of customers activate without friction. You'll see the impact of your work in the numbers, weekly, with the autonomy of a senior engineer in a squad that trusts you to own outcomes rather than tickets.

Based in Sydney, reporting to the Head of Engineering.

Apply now, or reach out for a confidential conversation.

📌 Senior Full Stack Engineer | Headless CMS, Identity & Internationalisation (Sydney)
🏢 Big Wave Digital
📍 Sydney