Our recent research (Budish, Cramton and Shim, 2013) proposes frequent batch auctions – uniform-price sealed-bid double auctions conducted at frequent but discrete time intervals – as a market design alternative to continuous-time trading in financial markets. This short paper discusses the implementation details of frequent batch auctions. We outline the process flow for frequent batch auctions, discuss a modification to the market design that accommodates market fragmentation and Reg NMS, and discuss the engineering and economic considerations relevant for determining the batch interval.