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
