Nubank sees efficiency in its AI model, invests in own GPUs
Bank working toward launching AI private banker for clients
Digital bank Nubank says it is reaping the benefits of developing its proprietary AI model and is investing in its own compute layer.
The centerpiece of the AI strategy is NuFormer, Nubank’s proprietary foundation model for financial behavior that was launched last year and is now is in its latest generation, founder and Chief Executive David Velez said in the bank’s second-quarter earnings call on Thursday.
The Sao Paulo-based bank has spent the past year building “a single AI platform that powers business and customer decisions across Nubank,” Velez said, adding that work now includes owning more of the infrastructure beneath it.
“We increased and upgraded our own GPU fleet, giving us full control of the compute layer,” Velez told analysts, tying that buildout to expanded architecture research efforts.
The latest NuFormer model is built on architecture similar to open-source models such as Kimi K3 and Qwen3.5, Velez said, adding that the efficiency and cost to run NuFormer improves each quarter.
“Today we can achieve the same predictive performance with 20 million fine-tuning data rows that previously required over 400 million, cutting development cycles from weeks to days,” he said.
Nubank’s disclosures pointed to several concrete gains from the AI platform:
- AI agents handle more than 60% of customer support conversations in Brazil;
- The newest generation quadrupled context length, training speed and inference speed while lowering production costs;
- More than 100 marketing campaigns already have run using NuFormer-driven customer targeting; and
- Headcount held roughly flat at 10,400 even as the bank scaled, with Velez projecting employees will be up to five times more productive as AI adoption deepens.
By the numbers
In Q2, the bank reported:
- Net income of $1.1 billion, up 49% year-over-year;
- Gross revenue of $5.9 billion up 39% YoY; and
- An efficiency ratio of 20% compared with 21% in Q2 2025.
AI private banker
Beyond underwriting and support, Nubank is using the model to guide product recommendations, personalize its app and “move toward our vision of an AI private banker,” Velez said.
He also addressed recently joining OpenAI’s board, framing it as a two-way exchange rather than a strategic pivot.
AI, he said, remains “the most important technology transformation” the company has navigated and that the OpenAI seat gives him “a very interesting insight” into how frontier labs are building the technology Nubank is deploying internally.
Management didn’t disclose GPU spend or headcount tied specifically to the compute buildout.
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