At trivago, we use a Cucumber based framework for end-to-end tests of our most important web applications. Cucumber stores test result as JSON files which can be turned into human-readable test reports.

When I joined trivago a year ago, we had problems with our releases. The traffic was increasing each day. When we put the server back into the load balancer without warming up the OPcache it would die. From time to time the warmup failed silently. Our DCO (data center operations) crew had to log into the servers and restart a few processes manually. During this time every release was very intense.

When using webpack to build your assets, it's only a matter of time until you wish for targeted builds. Whether it's the output of the library you're working on (CJS, UMD, AMD, Var, etc.), or the specific feature set (IE8 support, no IE8 support). parallel-webpack can run those builds in parallel, thus making full use of the multi-core processing capabilities of modern devices.

You know those bugs, like, those. Where the application state dances around you like a crazed Polynesian fire dancer. Where changing the sorting order of a search in London reverts the result list back to Paris.... Seriously? Unfortunately, a lot of us are specialists in dealing with this kind of bug.