Senior Full Stack Engineer - AI Harness

Xero; Auckland; Remoto; NZD 140.000 - 180.000; Tempo pieno

Descrizione del lavoro

Xero is seeking a senior engineer to own a critical delivery stream on MyXero, a foundational platform handling hundreds of millions of daily requests. You will shape durable architectural solutions, specs, and AI guardrails enabling software agents to implement safely.

You will modernise a massive system into decoupled domain services, build automated verification loops, and mentor teammates to uplift engineering practices and reliability across the team.

Competenze

• Deep full-stack or backend engineering experience with typed languages (C#/.NET).
• Hands-on exploration with AI harnesses, coding agents, or automated verification pipelines.
• Experience with distributed systems architecture and API design.
• Data modeling and managing complex relational database migrations.
• Proven ability to take ambiguous technical problems from concept to production.
• Strong written communication for design records and technical documentation.

Mansioni

• Owns critical delivery stream on MyXero platform.
• Designs specs, verification harnesses, and AI guardrails for safe implementations.
• Develops automated verification loops and test harnesses.
• Mentors teammates and contributes to safe engineering practices with intelligent tools.

Conoscenze

Backend engineering

C#/.NET

AI harnesses

Distributed systems

API design

Data modeling

SQL migrations

Technical documentation

Collaboration

Strumenti

SQL Server

Azure

Git

Descrizione del lavoro

The role / impact

This senior engineering position owns a critical delivery stream on MyXero, the foundational platform that underpins every organisation and user record while managing hundreds of millions of daily requests. You will take ambiguous platform challenges from problem framing to durable architectural solutions, designing the specs, verification harnesses, and AI guardrails that enable software agents to handle implementation safely.

The role / impact

This senior engineering position owns a critical delivery stream on MyXero, the foundational platform that underpins every organisation and user record while managing hundreds of millions of daily requests. You will take ambiguous platform challenges from problem framing to durable architectural solutions, designing the specs, verification harnesses, and AI guardrails that enable software agents to handle implementation safely. Your work directly enables the modernisation of a massive system into decoupled domain services without disrupting dependent products. By engineering automated verification loops and robust testing harnesses, you will ensure high reliability, mentor team members, and shape how our engineering practices operate safely with intelligent tools.

The Team / How They Connect

You will join the MyXero Ghostbusters squad within our Identity and Platform group, collaborating with engineers and product partners primarily based across New Zealand. The team operates with a written-first, remote-first philosophy, using design records, paired kick‑offs, and blameless reviews to ensure every voice is heard and no one works in isolation. While delivery is high‑tempo, the group maintains a supportive, open environment where technical curiosity and shared learning are core to daily routines.

Initially, you will focus on

• Setting up an intentional local development harness with automated validation checks to safely handle production changes.
• Refactoring legacy monolith endpoints and services built on .NET Framework, C#, and SQL Server towards modern APIs.
• Developing automated verification loops, test simulation harnesses, and tools that reduce operational toil and human checks.
• Building cloud agent tooling and collaborative workflows that support the evolution toward an automated development lifecycle.

Where And How You Can Work

This role is open to candidates based in New Zealand, offering a flexible remote‑first setup with office access in Wellington or Auckland. Our working environment is structured around async communication and balanced collaboration.

Here are some of the things we are looking for

• You bring deep full‑stack or backend engineering experience with typed languages, ideally with exposure to C# and .NET environments.
• Hands‑on exploration with AI harnesses, coding agents, or automated verification pipelines in a personal or professional setting.
• Practical familiarity with distributed systems architecture, API design, data modeling, and managing complex relational database migrations.
• Proven capability in taking ambiguous technical problems from initial conception to production delivery.
• Strong written communication skills to articulate system trade‑offs clearly through design records and technical documentation.
• A collaborative mindset with a drive to share learnings, uplift team capabilities, and contribute constructively to production support rotations.