ANDRII VARUNOK

Built a centralized chat and notification service using Go. Integrated it via NSQ to handle real-time events from IoT vehicle trackers, CRM updates, and employee time-tracking systems.

Rewrote the entire Authentication & Authorization module in Python, moving from a legacy implementation to a more secure and scalable architecture.

Refactored legacy code and optimized database queries, reducing API response times to 50–100ms for the most heavily used endpoints.

Developed a high-load survey platform with crypto rewards capable of handling traffic peaks around 10,000 requests per second.

Implemented a statistical performance evaluation system that calculated salary adjustments based on p90, p95, and p99 percentiles of employee data.

Engineered a real-time collaborative data grid (similar to Google Sheets) using WebSockets, allowing multiple users to edit tables simultaneously without conflicts.

Built a data labeling tool for training Machine Learning models, which included an integrated live chat for better team coordination.

Mentored junior developers and interns, conducting code reviews and helping them grow professionally.

Built a control service in Go. It processed real-time coordinates from an external Computer Vision module to automatically adjust the navigation path with high precision.

Used Raspberry Pi 5 as a low-latency bridge to connect the digital system with the hardware microcontroller.

Customized and stripped down Raspbian OS. I wrote scripts to optimize the boot time and reduce resource usage so the system would run stable in difficult environments.

Delivered custom web solutions and automation scripts for small businesses using Python and PHP.

Designed and secured local networks for small offices, handling routing, switching, and firewall configurations.

Maintained Linux servers and provided hardware troubleshooting, helping clients keep their infrastructure stable and secure

Developed and maintained websites for local business clients.

Configured and secured local office networks, handling routing, firewall setup, and general troubleshooting.

Provided technical consulting on hardware selection and IT infrastructure for small businesses.

Developed and maintained the organization’s website.

Managed the IT infrastructure, ensuring all workstations and peripherals were running smoothly.

Configured the local network and handled hardware troubleshooting for staff.