Maintenance and refinement of the medical information system. Platform: GNU/Linux. Technologies: PHP 7.4, Oracle 11g, PL/SQL, JavaScript. Version control system: Git.

Maintenance and refinement the billing for software by subscription service. Platform: GNU/Linux. Technologies: PHP 7.2, PostgreSQL 9.6, PL/pgSQL, JavaScript, RabbitMQ. Frameworks and libraries: Zend 1.2, JQuery. Automation scripts: Bash, Python. Package manager: Composer. Version control system: Git.

Web-development: the company site and web-application — the part of the SAAS product. Platform: GNU/Linux. Technologies: PHP 5.4, JS, CSS3, NodeJS. Frameworks: Laravel 5, AngularJS 1.2. Package managers: Composer, Bower, NPM. Automation scripts: Gulp, Bash. Version control system: Git.

Development of web- and Linux-applications of the internal infrastructure of the company. Implementation and refinement of applications with open source. Building a system of unified authentication and authorization. Administration of servers based on GNU/Linux. Creating and maintaining a single IP-telephony network with the call center module. Platform: GNU/Linux. Technologies: SMTP, DNS, VoIP, XMPP, LDAP, PostgreSQL, PL/pgSQL, C. Version control system: Git.

Development of the web interface for a mobile content management system. Platform: GNU/Linux. Technologies: PHP, MySQL, JavaScript. Framework: ExtJS. Version control system: Subversion.

Development of cash terminal software, server of processing and administrative web interface. Platform: GNU/Linux. Technologies: C++, Python, PostgreSQL, PL/pgSQL, PHP, JavaScript. Frameworks and libraries: Qt, Yii, JQuery. Version control system: Git.

Development of job-searching web-portal. Platform: GNU/Linux. Technologies: PHP, MySQL, JavaScript. Frameworks and libraries: Yii, JQuery. Version control system: Git.

Development and maintenance payments processing system: cashier workstation software and payments processing server. Platforms: GNU/Linux, MS Windows. Technologies: Java, PostgreSQL, PL/pgSQL, Delphi. Version control system: Git.

Maintenance of Linux-, FreeBSD- and Solaris-servers, NAS. Servicing of the mail system, web, DBMS (Oracle, Firebird). Equipment: HP servers, HP SAN. Tools and technologies: GNU/Linux, FreeBSD, Solaris, Oracle DB, Firebird, SMTP, DNS, Apache Web Server.

Maintenance of Linux- and FreeBSD-servers, network monitoring systems, IP-telephony systems. Development of services based on Cisco Call Manager. Collection and processing of statistics on the services provided. Tools and technologies: GNU/Linux, FreeBSD, MS SQL Server, SQL, Transact-SQL, Cisco Call Manager, VoIP.

Administration of Linux-based servers, active network equipment. Development and implementation of network monitoring and troubleshooting. Interaction with the RIPE for registration of an autonomous system and the allocation of blocks of IP-addresses. Interaction with backbone operators. Equipment: Cisco, Alvarion. Tools and technologies: OSPF, BGP, STP, GNU/Linux, Bash, DNS.