“DeepSeek-V4.1-Flash: Pushing the Limits of KV Cache Compression” With the rise in popularity of long-horizon agents, prefill compute and KV cache storage are becoming major efficiency bottlenecks as context lengths grow. DeepSeek-V4.1-Flash attacks this at the architecture level. Its new Causal Encoder-Decoder architecture computes the lower half of the network as an encoder, then projects decoder global KV directly from the encoder state, cutting prefill complexity from roughly O(NL) to…