Have you tried Hashnode Stories? The editor is capable of handling code examples using the markdown code syntax or by adding an embed. There are lot's of code heavy stories on the site, so it's definitely possible to accomplish what you are trying.
Also, if the content you create is interesting and engaging, which I'm certain of, you can be promoted by the Hashnode team as they share these posts on their twitter account.
If Hashnode Stories doesn't fit your needs, you can submit a feature request and the team will make sure your voice is heard.
Another solution will be to create a personal blog and promote the content by yourself. This can be really time consuming, but on the other hand give you better results if executed properly. You can share your tutorials on websites like reddit, Hacker News, Hashnode, twitter - the list goes on.