I built a REST API for Australian business data - here's how

If you've ever tried to programmatically look up an Australian Business Number, you've probably met the ABR's SOAP/XML web service. If you've tried to get ASIC company details or ACNC charity records, you've discovered they don't have an API at all — just weekly CSV dumps. I built OzRegAPI to solve this. It's a REST/JSON API that wraps all three government data sources into one interface. Here's how I built it, what decisions I made, and what I learned shipping my first paid API product. The problem Australia has three separate business registries: ABR (Australian Business Register) — ABN lookups, entity details, GST status. Has an API, but it's SOAP/XML with a WSDL you need to parse. ASIC (Australian Securities and Investments Commission) — Company registrations, types, directors. No API. They publish a ~400MB CSV file weekly. ACNC (Australian Charities and Not-for-profits Commission) — Charity records. Also no API. Also a weekly CSV. If you're building accounting software, a customer