DeepSeek published a 31-page systems paper detailing DSec, its self-developed elastic computing sandbox platform for large-scale agent training. Led by founder Liang Wenfeng, the 130-author team reveals DSec's production capabilities: a standard unit with 30,000 CPU cores handles 3 million instances daily and supports over 380,000 concurrent sandboxes. The infrastructure significantly reduces resource costs and improves memory efficiency, showcasing the underlying engineering supporting DeepSeek's massive training operations.