Hello, I'm Denys Dmitriiev
Senior DevOps & Cloud Infrastructure Engineer

DevSecOps Engineer experienced in GitLab CI/CD, Linux and cloud infrastructure, Docker/Kubernetes operations, Drupal platform migrations, automated dependency security, Fastly/Cloudflare CDN & WAF edge security, and centralized observability. Delivered standardized project onboarding and deployment pipelines while coordinating secure releases, production changes, and cross-team migration work.

• GitLab CI/CD engineering: Designing, migrating, operating, and troubleshooting delivery pipelines across multiple projects.
• Application and platform onboarding: Moving projects into standardized hosting and deployment environments.
• Drupal platform operations: Coordinating Drupal migrations, core/security updates, deployment workflows, and lifecycle maintenance.
• Edge, CDN & WAF operations: Fastly CDN & VCL edge snippets, Next-Gen WAF bot protection, rate-limiting, CAPTCHA tuning, Cloudflare CDN/WAF rules, and ELK log investigations.
• Web application security at the edge: Implementing and validating HSTS, CSP, Referrer-Policy, TLS/SSL, and secure HTTP redirects.
• Infrastructure automation: Using Bash and Python to automate repeatable operational tasks.
• Containerization and orchestration: Docker image/container management, Docker Compose, and Kubernetes workload operations.
• Cloud infrastructure administration: Azure VMs, networking, snapshots, compute provisioning, and cost-aware resource management.
• DevSecOps and vulnerability management: Security advisory assessment, patch deployment, dependency maintenance, and security-focused release processes.
• Dependency automation: Renovate Bot integration, automated update workflows, QA validation, and merge-request hygiene.
• Observability engineering: Graylog administration/handover, centralized log management, operational troubleshooting, and incident investigation.
• Linux systems engineering: Administration and hardening of Ubuntu, AlmaLinux, and RHEL environments.
• Web and network operations: Nginx, TLS/SSL, reverse proxies, DNS, SMTP, and production debugging.
• SaaS Identity & Access Management: Account provisioning/deprovisioning, RBAC, and MFA enforcement across Google Workspace and Microsoft 365.
• Infrastructure-as-Code and configuration management: Reusable environment configuration and automated provisioning practices.
• Release and change management: Coordinating downtime expectations, migrations, stakeholder communication, and controlled production changes.
• Technical collaboration: Working across development, QA, security, project management, and customer-facing teams in English, German, Russian, and Ukrainian.

Maintained high-availability distributed infrastructure for mission-critical web hosting and global web services.

• Maintained high-availability infrastructure for mission-critical, large-scale web services.
• Automated incident response procedures, reducing Mean Time to Resolution (MTTR) by 60%.
• Collaborated with development teams to implement core SRE principles and error budgeting.
• Performed capacity planning and performance optimization for distributed systems.

Led campus-wide IT infrastructure, enterprise mail platforms, virtualization clusters, and institutional IT security governance. Administered Linux mail systems, Google Workspace, and Microsoft 365 tenants for thousands of academic users.

• Mail System Administration: Administering Postfix, iRedMail, and Amavis mail servers, managing SMTP authentication, anti-spam/anti-malware controls, and mail-flow troubleshooting.
• Google Workspace Administration: Managing user and group lifecycle, domain and DNS records, Gmail administration, security controls, access management, and operational support.
• Microsoft 365 Administration: Entra ID identity management, Microsoft 365 user and license administration, Exchange Online operations, security groups, and tenant support.
• SaaS Identity & Access Management: Account provisioning/deprovisioning, role-based access control (RBAC), and multi-factor authentication (MFA) enforcement across Google Workspace and Microsoft 365.
• Systems Architecture & Security: Engineered high-availability server architectures, virtualization environments, network security, and institutional IT compliance.

Administered workstation fleet (up to 30 PCs), client IT support, website development, and hosting infrastructure.

Supervised technical support operations supporting over 2,000 ISP and digital television subscribers.