Codacy - Automatically reviews code style, security, duplication, complexity, and coverage on every change while tracking code quality throughout your sprints.
JavaScript Quiz - Check your knowledge by having fun.
DeepSource - Automated code reviews with static analysis.
The Ultimate GDPR Quiz - Learn how to get GDPR compliant in seconds
JavaScript Operator Lookup - A full list of JavaScript operators with examples
Triplebyte - Hire engineers by measuring their ability, not credentials