Andreas Tolfsen

Hello, I’m Andreas Tolfsen. I work on the underpinnings of the web platform, in particular on tooling and standards for interoperability and automation. This site curates some of the things I create.

Current projects

More projects at GitHub and on my git mirror.

Writing & presentations

Future of WebDriver presented at Selenium user groups in Belfast and Tel Aviv.

The case against visibility checks in WebDriver, positing that platform APIs to deal with hit-testing is necessary.

Thoughts on distributed bug tracking.


Tech determinism and its consequences


Old and new


Lunchtime brownbags

Over the Summer I’ve organised lunchtime brownbags in Mozilla’s London office. I recount some of the highlights and advice for replicating them elsewhere.

Persistent connections in WebDriver

A bug was recently reported that some of WebDriver’s error codes used the 408 Request Timeout HTTP status code and that this is in conflict with HTTP clients trying to use persistent connections.

WebDriver update from TPAC 2017

TPAC this year marked the culmination of six years of hard work defining the WebDriver standard. Here I talk a little bit about the new features that is coming.

What is libexec?

libexec is a system directory meant for system daemons and utilities executed by other programs, but which are not intended to be executed directly by users.