The Nord Pool system runs the process fixing the day-ahead hourly electricity spot prices in Northern Europe. Market mechanisms adjusts these spot prices to ensure the alignment of the power production schedule to the forecasted power demand. This price adjustment can be cast as a dual minimization problem, corresponding to maximizing the societal welfare of the market participants. However, this process is intrinsically static, in the sense that the spot prices are computed for each hourly bidding interval independently of the others. While valid today, this approach could be invalidated if the power demand becomes significantly price-responsive. EV charging, flexible consumers, prosumers, storage and Energy Communities will create such a price-responsiveness as they become wide-spread. In this chapter, we describe how a dynamic spot market could address the problem, while retaining the core properties of the current spot market, i.e., economically optimal energy exchanges, fair and transparent trading rules. We then show how Distributed Optimization can be used to tackle that dynamic spot market, in principle allowing for a large scale participation of flexible consumers and prosumers. We detail the process for Energy Communities, where novel spot market approaches can arguably be validated first.