Sergei K.Private profile: Upwork shows its earnings only to signed-in members, so we check it every few weeks, not daily. MRR here is a rough estimate (Upwork's six-month earnings ÷ months active). Last read Nov 5, 2026.

I am a Full Stack Web developer. I am proficient in PHP and have a lot of experience working with in Yii, Laravel, Cryptocurrency and other modern technologies. I follow OOP, SOLID concepts and best practices. I work as a part of a Scrum/Kanban team. I respect Agile principles and always work hard to deliver on time. I am a friendly person with a sense of humor and a good team player! But my most important tool is my reliability, attentiveness to the details and ability to learn fast. I would be happy to cooperate with smart people and carry out your fantastic ideas! SKILLS: - PHP Frameworks: Yii1/2, Laravel - JS Frameworks: React JS, Vue.JS - JavaScript, jQuery, jQuery Mobile - Front-end: HTML5, CSS3, Bootstrap 3/4, SASS, LESS - Template engines: Twig, Smatry, Blade - Databases: MySQL, PostgreSQL, Database optimization - NoSQL: MongoDB, Redis, Memcached - Git version control system - Vagrant virtual machines, Puppet - Automatic testing: Unit, Functional, Acceptance - API integration: Social, Payment, Cryptocurrency - OOP, SOLID and MVC concepts