Ivan Kleshnin

Experienced software engineer, mentor and entrepreneur. 12+ years in webdev. Generalist. Proponent of minimalism and 改善 (kaizen). In his free time, Ivan creates learning materials and blogs about programming and web development. As a mentor, prefers to give knowledge that will remain relevant over the years.

years of
mentoring experience
author exercises
at Paqmind.com
educational articles
and tutorials

Learning Programs

Frontend Development with React

Conquer the world of web clients with React and ReactRouter! Master JSX and components, state and composition patterns. Use functional and async tools to build modern SPAs.

Programming with JavaScript

Become a wizard apprentice with JavaScript knowledge! Master the key programming concepts: statements, expressions, side-effects, mutability. Learn how to write a concise and pragmatic code and how to refactor a bad one.

Individual Consulting

Need a career advice? Got a bunch of questions with no simple answers? An experience engineer will help with your troubles!

Professional Experience

... TODO ...

Random Achievements

  • JavaScript TOP 10 in Warsaw by GitHub Awards
  • Consulted remote "Forbes" teams at PowerToFly, EpicGames, Toptal.
  • Performed technical review for Packt Publishing.
  • Author of 250+ programming and dev. exercises at Paqmind.com
  • Author of almost 50 educational articles and tutorials
  • Contributed to a 3D editor for KwambIO.
  • Implemented a custom markup language & compiler for Paqmind.
  • Made a complex social portal in 500 hours for Inshipping.
  • Contributed to popular libraries: CycleJS, Nunjucks, Parsimmon, etc.
  • Open sourced a number of libraries in JavaScript and Python.
  • Authored a few frameworks and CMS'.

Students' Testimonials

Vitaly Zibulski
Web Developer
I'd like to tell about Ivan who was my mentor for a month. During this month he was open for any question 24/7, ready to help with all problems I asked him about. With just a few lessons it was clear that this person has a huge baggage of knowledge and he's willing to share it with his students. The...
Read more
Angelika Kachur
Frontend Developer
I was lucky to get an experience of learning and working with Ivan as my mentor. Ivan raised clear and detailed technical tasks that were interesting to solve. Ivan answered my questions and created an individual training plan for me to become a front-end developer. Now I'm a junior frontend develop...
Read more
Viktor Kutuzov
Frontend Developer
I have technical (yet unrelated) education and I have never worked in IT. Hovewer, I was always attracted by this industry. I reached all possible heights at my current job. Seemed like a perfect time for something new. So I decided to reeducate myself and go into IT. I started with learn.javascript...
Read more
Igor Pylaev
Frontend Developer
I was mentored by Ivan for several months now, and I highly recommend him. During this time, he has shown that he has the technical and interpersonal skills that make him a truly exceptional mentor. He helped me to become front-end developer step by step. He gave me interesting and, sometimes, chall...
Read more
Denis Davydov
Frontend Developer
Studied with Ivan for about a month and found a job after that. Straightaway I felt myself like a pioneer: new discovery, new knowledge or at least new experience every day. I have to say, I realized a substantial difference between an unguided learning and a mentored one. Going to details – I've q...
Read more
Andrei Saveliev
Frontend Developer
From the first days, Ivan revealed the specifics of the Frontend profession to me. Made and individual learning plan, based on my needs. In the process of learning, he made qualitative code reviews which helped me to write more sophisticated and expressive code. Also he responded in details to all m...
Read more
Alexander Panchuk
Frontend Developer
After learning javascript.info decided to continue my learning with mentor. The choice fell on Ivan, bought over by his approach to mentoring, ability to give knowledge from the very fundamentals to that modern techniques. He builts learning program well, tailoring it to your goals and talents. Dur...
Read more
Serhii Dmytrakov
ML Engineer
One day I decided to become a fullstack developer and learned VueJS and then ReactJS. I even got a first job and imagined a bright future ahead. Soon I realized my mistake – I didn't knew fundamentals, like Async Programming or JavaScript itself and it undermined my further progress. Ivan Kleshnin ...
Read more
Dmitry Topornin
Backend developer
I subscribed to Ivan's mentorship with a background in Ruby & RoR. Due to his trainings, got pretty inspired about SPA applications as well. Despite my love to Ruby, you can't avoid JS today, and after his program – you don't want to :) If you're experienced developer, Ivan always find a few non-tr...
Read more
Alexandr Dorofeev
Frontend Developer
When I subscribed, I had basic JavaScript knowledge with no idea how to convert them to something practical. I didn't expect that hard topics of CSS and JS will be explained to me in so clear manner. Note, that I never programmed before and while I'm still far from a confident engineer the progress ...
Read more
Artem Kozyrev
Frontend Developer
Subscribed to Ivan's mentorship having no practice in my baggage, only a scarce JS theory. Just in two weaks I've got the skills I wanted, mastered the basics of ReactJS, and wrote my first realistic frontend application. In the course of training, quickly realized that I turned to a right person. ...
Read more
Anatoly Babin
Fullstack Developer
Practiced with Ivan for 2 months. Can advise him as an experienced developer, who understands how to choose the learning content, appropriate to his student's level. Ivan made an individual learning plan for me and kept giving invaluable advices in the process. In the future, I will definitely be ba...
Read more
Alex Malyita
Fullstack developer

I've just finished NodeJS Beginner tutorial. And the only question I have – When the next part?! No seriously, the content is amazing and the approach is truly unique. I'm definitely going to continue.

Dmitry Borowsky
Fullstack developer

Functional Programming series is very cool. Enjoyed the exercises, though over some of them I had to sweat :) A lot of new concepts and tricks for me. Thank you guys!

Student's Projects

Food Oils Base

An interactive table to compare fat profiles of food oils.

Made by Viktor Kutuzov

HTTP Clients

A comparison table of HTTP clients in JS ecosystem

Made by Dmitry Topornin


Deciphering of ananalog Morze codes in real-time

Made by Maksym Smagin