Ace Your Next JavaScript Interview
Hi, I'm Jesper Loso, a Tech Lead who's helped scale teams at My Neighbor Alice and Aira. Learn the async JavaScript challenges I actually use when interviewing developers, from trading system architectures to IoT platform design.
Interview Prep That Works
Practice with real interview questions from tech companies
Real Interview Questions
Practice with actual async challenges I've used while hiring at Handelsbanken and Aira
Insider Knowledge
Learn what tech leads actually look for in code reviews and system design interviews
Interview-Ready Skills
Master the async patterns top tech companies actually use in production
Practice Like It's The Real Interview
Get feedback from someone who's conducted hundreds of technical interviews
Real Interview Environment
Practice in conditions that match actual technical interviews, with the same time pressure and expectations
Technical Interview Feedback
Get the same detailed code reviews I give during real technical interviews
Success Stories
From interview preparation to landing the job
Emma S.
Hired at My Neighbor Alice
"The system design questions and async patterns I learned here were exactly what came up in my senior dev interviews. Jesper's insider perspective was invaluable."
Rasmus Rudling
Founder of Julo
"I loved how easy it was to practise async JavaScript challenges right from my phone. The mobile-friendly interface meant I could prep for interviews anywhere—on the train, at lunch, or even in bed"
Alex W.
Passed Technical Round
"Having a tech lead's perspective on what makes good async code was game-changing for my interviews. The real-world scenarios helped me stand out."
Available Courses
Choose your path to async JavaScript mastery
Free Trial
Try out JS Brain Teasers with this course, free of charge. Get a feel for the platform
Junior Javascript Developer
Prepare for the first interviews for the junior javascript developer role. This course will go through all of the async code a junior developer absolutely needs to understand
Senior Javascript Developer
Prepare for that dream position that requires you to be an absolute star as the javascript event loop. This course will make sure that you can easily and intuitively tell how asyncrounos javascript code is executed
Ready to Ace Your JavaScript Interviews?
Get access to real interview questions and expert feedback from a tech lead who's been on both sides of the table
Start Interview Prep