The ranking covers 100 assignees drawn from the 533 records in scope, and it is concentrated at the top: the leading assignee alone accounts for 41 records, and the top five combined hold 128 records, or 24.0% of all 533. That leaves a long tail of single- and few-filing entrants below the ranked leaders, so a newcomer is not necessarily competing against one dominant blocker but against a cluster of five to ten active filers.

Filing volume rose steadily from 2 records in 2017 to a peak of 108 in 2025, but the most recent one to two years always understate real activity because publication lags filing by roughly 18 months. The only clean complete-year comparison is 2021 to 2024, which shows 77 records falling to 61, a -21% change best read as the field settling into a mature filing plateau rather than losing momentum, since the underlying invention work continues to surface in later publications.

WO2024127462A1, filed by NEC Corporation on 2024-06-20, claims an automatic machine-learning pipeline that runs a neural architecture search, narrows the candidate search space with an alpha-analyzer, compresses the resulting small model by replacing sublayers within that narrowed space, and then deploys the lightweight model. It blocks that specific sequencing of search-then-narrow-then-compress, but pipelines that narrow the search space using a different signal, or that compress without that intermediate narrowing step, sit outside its claim language.