Principal Mobile Application Developer - Fintech AI transformation - Sydney

Sydney | 5 days in the office | Big Wave Digital

Let’s get straight to it.

This is not a “keep the lights on” mobile role.

This is a build it properly, own it end to end, and make it world class role.

You’ll be joining one of Big Wave Digital’s premier partner clients.

A scaling fintech.

Real customers. Real volume. Real stakes.

They’re deep in an AI-led transformation, rethinking how their platform works, how customers interact, and how fast they can move.

No fluff.

No endless committees.

Just smart people, moving quickly, making decisions.

The mission

You own the entire mobile experience.

Not a slice. Not a feature.

The whole thing.

From architecture…

to performance…

to the feel of every interaction in someone’s hand.

This is principal level. That means:

You set direction.

You make the hard calls.

You raise the bar for everyone else.

And when customers open the app every day…

what they experience is on you.

What you’ll actually do

You’ll live in React Native and Expo. But this isn’t just shipping screens.

You will:

• Own the architecture and quality of the mobile app
• Define how mobile is built across the squad and influence beyond it
• Partner with Product and UX to create something that feels native, not “cross-platform”
• Obsess over performance across real devices, real networks, real users
• Own the entire release lifecycle
• App Store, Google Play, Expo EAS, OTA updates
• Build for low bandwidth, low power, real-world conditions
• Set patterns and tooling others follow
• Mentor engineers naturally, without needing a title to do it

What matters here

This role is for someone who cares about mobile craft.

You know the difference between something that works and something that feels right.

You probably:

• Have deep experience with React Native and Expo in production
• Understand the rendering pipeline, JS thread, and bridge behaviour
• Know how to diagnose and fix performance issues properly
• Have shipped across iOS and Android and understand their quirks
• Have handled the full release cycle, not just development
• Build with accessibility as standard, not an afterthought
• Think in terms of systems, not just features

Bonus points if you’ve worked with:

• Trading platforms
• Financial data
• Real time mobile experiences

The environment

Let’s address it upfront.

This is 5 days in the office, Sydney. Non negotiable.

And that’s intentional.

This team builds fast. Debates ideas in real time. Solves problems on the fly.

You’ll be surrounded by people who care about what they’re building.

If you like energy, pace, and actual collaboration, you’ll thrive here.

If you want slow, remote, and asynchronous everything… this isn’t your spot.

Why this role stands out

Most principal roles talk about influence.

This one gives you actual ownership.

Most fintech apps are iterative.

This one is being rethought properly, with AI shaping what comes next.

Most mobile roles are part of a machine.

Here, you help define how the machine works.

If this sounds like you

You’ve probably built things you’re proud of.

You’ve probably argued about performance tradeoffs.

You’ve probably cared more than most about how an app actually feels.

And you’re ready for something with real impact.

Apply via Big Wave Digital

Or reach out for a proper conversation. [email protected]