Senior Software Engineer — Fintech AI & Payments

Xephyr; Sydney; Hybrid; AUD 140,000 - 190,000; Full time

Job summary

Lessn is hiring a Senior Software Engineer to join its embedded engineering team in Sydney. You will build production systems across the payments orchestration platform and contribute to the AI/ML decision engine that optimises invoice payments.

You will mentor a graduate engineer, uphold code quality, and drive scalable engineering practices in a regulated fintech environment. This hybrid role combines office work and remote collaboration.

Qualifications

• 5+ years hands-on software engineering in production systems.
• Proficiency in Python and at least one strongly typed language (C#, Java, C++).
• Experience with cloud infrastructure and IaC.
• Ability to design and ship software independently in a small team with founders.
• Familiarity with fintech/payments is a plus.

Responsibilities

• Design, build and deploy production software across Lessn's payments platform.
• Contribute to the AI/ML decision engine design and delivery.
• Maintain reconciliations and integrations with accounting systems like Xero and MYOB.
• Champion repeatable, scalable engineering practices including CI/CD.
• Mentor a graduate engineer and uphold quality before production.

Skills

Python

C# / Java / C++

Cloud platforms

Infrastructure as Code

CI/CD

Independent delivery

Tools

AWS

Azure

GCP

Job description

Lessn is hiring a Senior Software Engineer to join its embedded engineering team in Sydney. You will build production systems across the payments orchestration platform and contribute to the AI/ML decision engine that optimises invoice payments.

You will mentor a graduate engineer, uphold code quality, and drive scalable engineering practices in a regulated fintech environment. This hybrid role combines office work and remote collaboration.