Winery.js is a framework that enables services to run experiments along with production traffic in the same process. Besides A/B testing, it supports experimentation at per-request level, which minimizes turnaround time when code evolves fast. Winery.js also provides a structure for creating applications declaratively, with the access to Napa.js capabilities, such as multi-threading, pluggable logging, metric, and etc. Before this work was branched out as an open source project, it has been used in Bing to empower feature experiments for machine learned models. Winery.js was built based on the idea of dependency injection at multiple levels, thus its core is to encapsulate object creation and object retrieval behaviors with an overriding mechanism. White paper Continuous modification: a process to build constantly evolving services discussed this idea in details.