Data Engineer

About Maincode

Maincode makes Matilda, an Australian-made AI stack we own end to end, from tin to token. We own and operate our own infrastructure here in Australia, we train and maintain our own frontier models, and we run multiple surfaces on top of them, including chat, coding and API. Everything we ship is built on capability we control ourselves. We are hiring someone who cares about that. You should be passionate about Australian-made technology, a builder first, and keen to execute at the frontier of data engineering and model training.

The role

A frontier model is only as capable as the data it learns from, and every model carries the worldview of the data it was trained on. We did this for Australia with Matilda’s voice. Now we are building the capability to do it for any country or market: training open weights models on custom datasets that reflect the cultural, regulatory, governance, and ideological requirements of the people who will use them.

You will be the hands on engineer who builds the system that makes those datasets. You will own the pipeline end to end, from web scale crawling of hard to reach, country specific sources through to filtering, deduplication, quality control, and the agent driven pipelines that turn raw material into training sets. We need someone who moves fast, writes code every day, and knows how to use AI agents to multiply what a small team can produce without letting quality slip.

What you will do

- Build, run, and scale crawlers and scrapers for web scale collection, including specialized crawlers for high value, hard to reach sources such as legislation, regulator guidance, government publications, local media, and community forums.

- Develop robust pipelines for extraction, filtering, cleaning, deduplication, and formatting to ensure the highest quality inputs for model training.

- Build agentic pipelines where AI agents generate, annotate, critique, and verify data at scale, with the evaluation and spot che...