Job Description

Senior Backend Engineer (Python & AWS)

North Sydney | Hybrid (3 days in office)

This isn’t a role for someone who just wants to ship tickets.

It’s for an engineer who wants to shape architecture, modernise a real platform, and influence technical direction inside a profitable, globally operating data business.

The company operates at  serious scale, processing and resolving large volumes of identity and data signals used by major international organisations. They are stable, growing (40%+ revenue growth over the past two years), and backed by long-term enterprise contracts.

Now they’re ready to uplift their platform for its next phase.

What You’ll Love About Working Here

1. Genuine Architectural Influence
You’ll act as a 2IC to the Head of Technology. Your thinking will shape direction not just implementation.

2. Real Scale (Not Resume Scale)
Large datasets. Performance-sensitive systems. Complex resolution logic.
You’ll solve meaningful engineering problems, not UI tweaks.

3. Modernisation with Backing
There’s technical debt  and full leadership buy-in to fix it properly.

4. Stability Without Bureaucracy
Profitable. Long-tenured team. Flat structure.
No corporate red tape but strong standards and ISO discipline.

5. Ownership Over Noise
You won’t be one of 200 engineers.
You’ll be one of a small, high-trust team.

What You’ll Get From This Role

• End-to-end ownership of backend architecture decisions

• Exposure to large-scale AWS system design

• The opportunity to uplift engineering standards

• Influence over roadmap and prioritisation

• A stable environment where your work compounds over time

If you want to look back in three years and say,
“I built that platform properly” - this is that role.

What You Need to Have Already Done

This is not a stretch role.

To be successful here, you will likely have:

• 6–10 years backend engineering experience

• Designed and built production systems in AWS

• Strong Python expertise (Django/Flask or similar)

• Worked on systems handling meaningful data scale

• Made architectural decisions not just implemented them

• Improved performance, security, or scalability of legacy systems

• Influenced stakeholders and extracted unclear requirements

You must be able to:

• Think architecturally first

• Communicate with gravitas

• Operate without ego in a flat structure

• Prioritise effectively when everything feels important

Environment

• AWS cloud-native

• Python backend

• Snowflake and large-scale data querying

• Hybrid (Mon, Tues, Fri in North Sydney - weekly team lunches)

• Strong culture, many team members have worked together 10-15+ years

• Investment in learning and conferences

This role suits someone who wants impact over title.Ownership over hierarchy. And long-term influence over short-term noise.

If this sounds like you then apply here or share your resume to Dani - danielle@theonset.com.au