Senior AI and Integration Engineer for a multi-system business build (Australia, long-term)

We're building an AI operating layer for an established Australian trades and services business, and we're looking for an experienced engineer to build it. The core of the work is connecting the software the business already runs (HubSpot, ServiceM8, Xero, WhatsApp Business and a few others) so that one job flows through all of them as a single record, instead of being re-entered by hand in each system. On top of that sits a knowledge base the tools search to answer technical questions, with strict rules: every answer names its source, and if the tool isn't certain it hands over to a qualified person rather than guessing. This is a real, multi-month build working with sensitive business data. It is not a quick automation job. It will be delivered piece by piece, with each part going live as it's finished. The code lives in a repository we own, the data stays in Australia, and there's a security review before any real data is touched. What you'd be doing: - Connecting several live business systems into one reliable data layer, including two systems that are mid-migration - Building a searchable knowledge base that cites its sources and safely handles "I don't know" - Building AI-assisted tools on top of that layer, such as design checks, a field tool, a finance layer and a dashboard - Setting up testing, logging and cost tracking so the system is dependable and its running cost is known per job Who we're looking for: - Strong backend engineering (for example Python or TypeScript, databases, cloud hosting) - Real experience integrating live business systems through their APIs (please name which ones) - Experience building production AI or retrieval systems with grounding and citations, not just chatbots or demos - Awareness of data privacy and security, ideally with Australian data residency in mind - A track record of finishing substantial, multi-month builds - Clear, responsive communication, as you'll work closely with us, not directly with the end client Nice to have: - Direct experience with HubSpot, ServiceM8, Xero or the WhatsApp Business API - A habit of recommending an alternative, simpler or cheaper approach when one exists To apply: - A confidentiality agreement is signed before the full scope is shared - Please share examples of live systems you've built, whether integrations, AI retrieval work, or both - Answer the two screening questions