## Load balancing is impossible Load balancing is impossible as the load balancer can't know the latency of the request in advance ---- For a web page the number of requests means that one request is guaranteed to hit the 99 percentile ---- Joint shortest queue does not work in a distributed system as the information it had is out of date and under load it signs to much traffic to a few nodes. ---- Random choices is stateless but has the same profile as a single node JSQ implementation ---- Round Robin and Random have the same runtime profiles at scale ---- **CSS Transitions** with [Jad Joubran](https://github.com/jadjoubran) Some of the ways of getting fast animations are a bit disappointing. Using pixel sizes to avoid having the browser having to calculate dimensions makes sense but is throwing the baby out with the bathwater as well. Visual effects need to be handled off to the compositor which means using `transform`. Doing 3D transformations for 2D animation has been deprecated as a practice for mobile due to the poorer GPU supported. ---- [will-change](https://developer.mozilla.org/en/docs/Web/CSS/will-change) provides an optimisation hint that a property will change. Requires discipline to avoid over-application. Need to be careful with pseudo-selectors to make sure will-change is visible before the application of the selector. Requires profiling to prove that the optimisation has worked as expected. ---- [FLIP](https://aerotwist.com/blog/flip-your-animations/) ---- ## Serverless architecture > Serverless means not explicitly managing servers > AWS Lambda is to services what S3 was to storage ## Principles 1. Run code on compute services not servers 1. Write single-purpose stateless functions 1. Design push-based event-driven pipelines 1. Create thicker client-side applications 1. Use third-party services ---- Interesting argument that there shouldn't be a backend validation and logic layer. ---- ## PWA keynote Surely there is more to PWA than pinning things to your home page and faking an app wrapper. ---- It seems not, it's caching, notifications and homepage (but just on mobiles). I think Service Worker is interesting but on this basis it's not the new messiah.