James Hilliard (@james_hilliard) — Twitter Score 46 out of 1000

James Hilliard is a Bitcoin protocol and mining-firmware developer who authored BIP91, the consensus-layer soft fork specification that enabled SegWit activation with majority hashpower below the prior 95% threshold. James Hilliard's Twitter Score is 46 out of 1000 as of August 2026, ranking #19,730 (top 5%) among 484,613 tracked accounts.

James Hilliard serves as Chief Technology Officer at Upstream Data Inc., where he leads software initiatives and overall technology direction, including the company's US expansion. His BIP91 specification, formally titled "Reduced threshold Segwit MASF," was assigned in May 2017 and carries a status of Deployed, making it one of the more consequential Bitcoin Improvement Proposals of that period. He also develops Bitcoin-miner and distributed-computing firmware as part of his work at the company.

James Hilliard is an active contributor to Buildroot, the embedded Linux build system, with signed patches that include Bitcoin-package maintenance work. In 2019, he identified a vulnerability in Bitmain's Antminer S15 firmware, and after an anonymous researcher wrote and tested attack code, Hilliard publicly demonstrated the exploit, drawing attention to security risks in mining hardware firmware.

James Hilliard has accumulated 4,802 followers as of August 2026 and has published 746 posts. He has been mentioned by 35 accounts, with 66 total mentions.

Who follows James Hilliard on X?

The accounts that follow James Hilliard include 187 founders, 20 angel investors, 73 influencers and 1 VCs, among them Udi Wertheimer, Jesse Powell, Eric Wall, Tay, Ari Paul and Adam Back.