
Karina Ionkina
Karina Ionkina works as a senior software engineer on the Data Visualization team at Bloomberg, which builds and maintains multiple full-stack tools used by the company’s reporters and data visualization developers (see examples of these visuals at https://www.bloomberg.com/graphics). Outside of work, Karina likes to play tennis, paint, and sew. Karina earned her bachelor’s degree in computer science from Hunter College (CUNY).
Bloomberg, USAkarina-ionkina
What We All Pretend to Know: The Differences Between the JS Engine & JS Runtime
JSNation 2025

Upcoming
What We All Pretend to Know: The Differences Between the JS Engine & JS Runtime

Modern web development frameworks provide so many levels of abstraction that developers don’t need a deep understanding of the underlying runtimes or engines to hit the ground running. In fact, ease of use is the point of modern frameworks and a good indicator of their success. When spinning up an application, it’s easy to view Node as just “a piece of the puzzle,” and mistake it for a JavaScript engine, or a language, when, in reality, it is neither.It is valuable for developers to understand the differences between the engines and runtimes employed in their full-stack projects in order to have a mental model of how their code is being executed, and to optimize it for the environments in which it is running. The goal of this talk is to make clear the distinction between a JavaScript engine and runtime, to review how they interact with one another (in both servers and on the web), and to look at practical applications of this knowledge.