Anna Henningsen

Improving the autocomplete in MongoDB's database CLI seemed like a great idea. But when the team tried to flip the feature flag, things quickly started to go sideways: A story of memory leaks, bugs that touch the very core of JavaScript as a language, and hard-learned lessons about testing and performance.

Improving the autocomplete in MongoDB's database CLI seemed like a great idea. But when the team tried to flip the feature flag, things quickly started to go sideways: A story of memory leaks, bugs that touch the very core of JavaScript as a language, and hard-learned lessons about testing and performance.

Anna performs a deep dive into the anatomy of a regression that affected Node.js users in development and production in the past year, and analyzes how it gives us insight into how JS engines work under the hood and how Node.js itself is currently being developed.

Character encodings can be confusing for every developer, providing pitfalls even for the most experienced ones, so a lot of the time we want to end up with something that “just works” without an in-depth understanding of the involved concepts. In this talk, Anna will give an overview over what they are, what the JavaScript language provides to interact with them, and how to avoid the most common mistakes in Node.js and the Web.

Node.js is famously a JavaScript runtime that encourages using asynchronous operations wherever possible – but what happens when you really, really need to do synchronous I/O? Anna gives an overview over the – surprisingly many – different ways to achieve this, and what we can learn about how the language and Node.js internals work from them.