Microsoft Chakra is the new JavaScript engine on the block, and the bugs are pouring in. This presentation discusses techniques for finding bugs in a ‘fresh’ ECMAScript engine. When standards are implemented, design decisions are made that can affect security for years to come. This talk describes some of the implementation details of Chakra and how they led to specific bugs, as well as some ideas for finding future bugs. Recommended for people who want to find more or better browser bugs!