I went looking for dropped requests during a rolling restart and found something more annoying than dropped requests: a deploy that looks perfect and isn't. Setup is deliberately boring. Two Node/Express replicas behind nginx, ten clients hammering an endpoint that takes three seconds, docker stop on one replica halfway through. The app is the version most of us have shipped at some point, with no signal handling at all: app . get ( ' /work ' , async ( req , res ) ...