Lucas da Costa

I’m a Brazilian software engineer, published author, and international speaker living in London. I’m passionate about open-source, and, for the past few years, I have been a maintainer of Chai.js and Sinon.js (two of the most popular testing libraries in the JavaScript world). Furthermore, I significantly contributed to numerous projects, including Jest and NodeSchool. As an author, I’ve written Testing JavaScript Applications, a book published by Manning Publications. I’ve spoken in more than ten countries and have had my content translated into Russian, Mandarin, French, Portuguese, and Spanish.