Serhii Ivanov 🇺🇦/🇵🇱

Software packaging expert Remote (side-project)

Software packaging expert (DEB, RPM), working on #1 open-source communications platform in the world on my own free time. Maintenance of build systems that utilize Autotools, Make, CMake. Packaging software for Debian and Redhat based Linux distributions. Maintenance of CI/CD workflows using GitHub Actions. Facilitation of partial migration from Bamboo to GitHub Actions.

• Build systems (Make, CMake) and distribution of built packages (DEB, RPM)

Senior Software Developer Remote

Developing and managing Kubernetes operators and ClusterAPI providers (Kubebuilder, Operator SDK, Client-Go) that handle BareMetal server provisioning and life-cycle management (metal3.io/baremetal-operator, dnsmasq-operator, artifacts-controller). Developed iPXE edge controller that bridges the integration gap between Kubernetes and OpenStack Ironic. Developed DHCPv4 Relay in pure Golang tailored specifically to dynamic environments such as Kubernetes clusters. Enhanced system scalability, performance, and robustness through continuous improvements and code reviews and effectively solved BareMetal servers provisioning performance issues in huge Kubernetes clusters that increased the provisioning performance up to 10x. Collaborated closely with system engineers and developers to address complex system requirements. Actively participated in the open source community, contributing to various related projects (Metal3.io, OpenStack).

• Kubernetes operators for Kubernetes on BareMetal Servers

Software Engineer (Golang) / Team Lead Ukraine, Kyiv

Team leadership, project coordination, and mentoring junior staff. Developing back-end infrastructure-related services using Golang with some front-end: - Fanotify-based file modification monitoring for Linux containers running on the host node. - Repackaging PHP (pre 7.x) packages for simultaneous mod_apache use on Debian. - Custom L7 (and L2/L3) DDoS protection using Nginx, an image captcha server, JS hash challenge, and a distributed netfilter ban list. - Distributed TLS certificate storage using Golang FUSE filesystem and alternative implementation using Nginx NJS. - Oversees the development of an in-house container backup solution that uses file-level snapshots. - WebUI for container backup solution using Gin, Semantic UI, and PostgreSQL. - PoC system level (PID1) containers control using opencontainers/runc and alternative implementation using LXC Golang bindings. - Network hooks for LXC/LXD and Libvirt for advanced networking setups (TC rules, policy routing, netfilter rules, VxLAN, MAC-Spoof protection). - API, WebUI, and CLI for taking website screenshots using CDP and headless Chromium, with perceptual hashing algorithms for change detection and reporting. - JSON-RPC over HTTP framework with in-house validation framework for PHP Symphony-based client integration. - PoC Libvirt control plane using JSON-RPC over HTTP framework. - JSON-RPC over HTTP API for iLO (HPE BMC) access over NAT (additional level of security). - Custom Cgroups monitoring agent and receiver for Linux containers with Clickhouse as time-series storage and dynamic Grafana dashboards. - Linux container management control plane based on JSON-RPC over HTTP, running on container host nodes and communicating with container agent via execv pipes.

• Team lead, Mentor, Golang developer

DevOps Engineer Ukraine, Kyiv

BareMetal server, Linux Containers provisioning and maintenance using custom solution and SaltStack leveraging Salt-SSH with security patched SSH server on container side and Salt in Master-Minion mode for BareMetal servers.

• SaltStack, automation

System Administrator Ukraine, Kyiv

Administration (including physical setup), provisioning, and monitoring of the network infrastructure and equipment, BareMetal servers, services, and data transport channels using Zabbix and Nagios. Customer consultation and extensive technical support including tailoring Linux Containers based hosting solutions to meet the various customer requirements: managed Nginx, Apache, PHP, MariaDB/MySQL, Redis, Memcached, Sphinx, Elasticsearch, Varnish, and other VPS-related software.

• Customer support (on-call)

System Administrator Ukraine, Kyiv

Customer support, Workstation and Server maintenance (Microsoft based solutions).

• Customer support

System Administrator Siversk, Ukraine

Setup and maintenance of Microsoft Windows based workstations, basic intranet infrastructure management.

• System administration

System Administrator Siversk, Ukraine

Setup and maintenance/administration of FreeBSD and Linux based servers for traffic billing, routing and media sharing.

• System administration