Luke Dashjr, known in the Bitcoin world as Luke-Jr, is a Bitcoin Core developer and the founder of Eligis mining pool. He has made over 200 contributions to Bitcoin Core, and maintains the Bitcoin Improvement Proposals section on GitHub.
Bitcoin Core
Dashjr has been contributing to Bitcoin Core and Bitcoin since 2011.
Segregated Witness, a proposal that among other improvements increases Bitcoin’s transaction capacity, was implemented as a soft-work with Dashjr’s help.
BFGMiner
Released in 2014 , Dashjr’s BFG Miner has become one of the most widely used implementations of Bitcoin mining software. It supports a wide range of mining hardware and is available on Mac, Windows, and Linux.
Eligius Mining Pool
Dashjr founded Eligius, one of the first Bitcoin mining pools. Today it amounts to less than 1% of the Bitcoin network hashrate. Eligius is an anonymous mining pool and no registration is required.
BIPs 22 & 23
Dashjr is responsible for BIPs 22 and 23.
BIP 22 added protocol support for long polling, which allowed to be notified of new templates immediately. BIP 23 allows miners to “check the basic validity of their next block before expending work on it, reducing risks of accidental hardforks or mining invalid blocks.”