Welcome to the Demian Kostelny website!


Sure, here you can find my own services of web and blockchain development. I'm can create for you your own smart contracts with Solidity, but also I can write for you your own NFT game :)


Here you can find technologies of your dream!


When I want to build some cool apps with PHP, I prefer to use the Laravel framework for building all app logic and API.


I provide nice services for the development of e-commerce websites and everything that I can build with WordPress CMS.


The main front-end framework that I'm using - is Vue, and the reason for that is the simplicity of this tool.


There is also no problems with writing custom ERC721, or EC20 smart contracts for your DApp.


So when I want to build a new Solana program - I use Rust, Anchor, and TypeScript to do that.


I have good skills with PHP development - want to build some apps? Use PHP ✌️


My story begins in 2017 when I had programming only as a hobby, but soon this become more interesting for me that just coding some small scripts or calculators. And then I began my path as WordPress/PHP developer, and in the spring of 2018, I got my first job as a Junior WordPress developer. In that days I was a real noob 😉

Soon with more practice and time, I started becoming more and more professional in this part of my development. Today I have 3 years of experience in web development and I can say that with all projects that I created and experienced I become a Middle PHP Developer. But also I started my path in blockchain development, in this kind of development I’m not super – but I’m like a junior blockchain dev ✌️

Sometimes I like to write some articles about web development or make courses for Udemy, and I do this in my free time. It’s cool to feel that the material that you created helps someone to become a much better developer 🔥 And yeah, if you want – you can find my book “PHP Junior Kit” on Google Play Books.


But that's not all


2018 May - 2018 Oct | Morkva | Junior PHP Developer

Templates and plugins development for WordPress websites.

2018 Oct - 2019 Jan | Anvi | Wordpress Developer

Fixing bugs and updating websites/plugins that were created with WordPress.

2019 Jan - 2019 Jun | Freelance | PHP/Wordpress Developer

Apps development with Symfony and Laravel.

2019 Jun - 2020 Feb | Sovalogic | Laravel PHP Developer

Apps development with Wordpress, Laravel, Symfony, React.

2020 Feb - Now | Self Employed | Wordpress/Blockchain Developer

E-commerce development and smart contracts writing with Solidity.

Latest from blog

Tech articles, tutorials, courses and other things that can upgrade your skills you can find here


Set up Laravel app with Inertia.js, React.js, and Vite.js

If you want to create a new Laravel application that will use React for client-side, and everything will be only on one server, this article is for you. Today I’m gonna show how you can set up a new Laravel application that will use React with Inertia.js. So let’s begin🤘 Create application First of all, […]

AWS S3 and Laravel Filesystem

When we want to build a real scalable Laravel app and don’t save users’ files in app storage — we will need to use an AWS S3 Bucket service. So what’s this means and how this works? How does AWS S3 Bucket work? If you haven’t heard anything about Amazon Web Services, I’ll tell you […]

Laravel and GraphQL? — Guide for beginners

Maybe one day you will have a task to integrate Laravel and GraphQL into one app. Or to create GraphQL API by using only Laravel. In this short article, I’m going to show you how you can do this by using one composer package — and how you will build all schemas, types, and other […]

Laravel & Redis — Tutorial for beginners

As you see — in this short article I’m gonna show you how you can use Redis and Laravel. So, let’s begin 💥 And if you don’t know Redis — store, you can use it to save some hashes, sets, or even cache if you want. The logic of the Redis store is simple key-value. That’s all […]


For now I started making my own courses for Udemy and also soon I'm gonna upload all this on my own YouTube channel. But here is some stuff that you can find.

GraphQL - Beginner's Course 2022

May 2022 - I published my new course on Udemy and this is a small course about the main concepts of GraphQL with Node.js

Vue.js - Complete Course For Beginners

In spring of 2020 I created my own Vue.js free course for Udemy. And now I've got 10k students and 4/5 rating 🎉

PHP: Junior Kit

So, in 2018 I wanted to write my first programming book - and here it is. This is PHP Junior Book, that's is good for beginners that want to become PHP Junior Developers.

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