Staff Site Reliability Engineer

Affix; City of Melbourne; Hybrid; AUD 180,000 - 240,000; Full time

Job summary

pay.com.au is hiring a Staff Engineer focused on SRE and reliability across AWS infrastructure. You'll own the reliability charter, establish on-call practices, and drive observability improvements using Datadog and Terraform.

You'll stay hands-on, shaping architecture and production risk, while guiding the engineering team to improve incident response and cost optimization in a fast-growing fintech environment.

Qualifications

• Experience owning an SRE or reliability charter end to end.
• Hands-on in AWS, preferably serverless (Lambda, ECS) and Terraform.
• Proven ability to define SLIs, error budgets and on-call practices.

Responsibilities

• Own the reliability charter for pay.com.au's infrastructure.
• Build on-call rotation, incident response and observability from scratch.
• Lead FinOps initiatives to optimize AWS costs while maintaining reliability.

Skills

SRE ownership

AWS

Incident management

Observability

Tools

Datadog

Terraform

Job description

• Funding: Raised approximately US$70 million in total funding
• Location: Windsor, Melbourne
• Ways of working: Hybrid, office 3 days a week (Mon, Tues & Thurs)

The Story

pay.com.au is one of the fastest-growing fintechs in Australia, already trusted by 100,000+ businesses to manage their payments, bills and expenses. The platform is processing billions of dollars a year, growing at roughly 80% year on year, with a fresh US$28M raise now fuelling US expansion. It's the kind of stage where the fundamentals start to matter more than ever, and reliability is becoming a genuine business priority.

The Role

This is a brand new Staff Engineer role. No incumbent, no existing playbook. You'll be the senior owner for SRE, AWS infrastructure, observability and incident management across engineering: building the reliability charter from scratch, standing up proper on-call and incident response, turning a newly rolled out Datadog investment into a real observability practice, and working with teams to establish SLIs and error budgets where none exist today. You'll stay hands-on, writing code and shaping infrastructure yourself, while lifting how the wider engineering team thinks about production risk.

The stack is AWS end to end, deployed through Terraform, with a fairly serverless architecture built on Lambda and ECS. Datadog has just landed. Cost optimisation and AWS monitoring are still open ground, so there's a FinOps practice to build here too if that's an itch you want to scratch.

Why This Is Interesting

Real scale, real stakes. pay.com.au processed $10B+ in TTV last year and is aiming for immense growth. This isn't legacy debt to untangle either: there's no existing SRE process, on-call rotation or observability discipline to fit into, so you get to decide what good actually looks like. You'll work closely with the CTO at a formative point for how the platform function gets built, with room to influence architecture and engineering practice well beyond the SRE remit.

Who Should Apply

Engineers who've owned an SRE or reliability charter end to end before: assessing the risk, building the plan, and doing the work to close the gap yourself. You're comfortable in AWS, ideally with serverless (Lambda, ECS) and Terraform, and you've built incident management and observability practice from a low baseline rather than just operating inside someone else's. Fintech experience isn't required. What matters more is judgment, a hands-on approach, and being someone who can turn an undefined problem into a plan people actually trust.