Dzmitry Sautchankau

The company has a working service with over 5,000 paid clients, but with a large amount of legacy code, which contributed to slow development and a high number of errors.

My task in a team of 5 people was:

- Gradual refactoring of the codebase from CodeIgniter to Symfony Framework, without impacting current users
- Development of new functionality
- Profiling and optimization of performance bottlenecks to enable a new free trial plan
- Communication and integration with other teams and company services
- Mentoring other developers on best practices for working with code

During my time there, approximately 30% of the existing legacy code was rewritten, resulting in a significant increase in the speed of developing new features and a decrease in the number of bugs.
Performance was improved in bottlenecks, allowing the launch of a free trial plan and attracting new users.
The development culture and quality were significantly improved.

Raisetech is a company focused on developing and maintaining complex, high-load projects. For example:
Project 1: 5element.by - Largest Online Store in Belarus with a daily audience of over 300,000 unique visitors.

As part of a team of 5 people, my tasks on this project included:
Significantly improving Google's page load speed metrics, which involved profiling and optimizing the performance of the main sections of the online store. The blackfire.io tool was used for profiling, and performance bottlenecks were identified and optimized through refactoring and the use of Memcache and Redis caches.
Developing a new price update service using the PHP Symfony Framework, MySQL, and RabbitMQ. Multiple iterations and performance improvements were made to the service.
During my work, the page load speed metrics were improved from a score of 20 to 90. The time required to update prices on the website was reduced from 1 hour to 10-15 minutes. These changes helped the company significantly increase its profits.
Project 2: beeretail.io - Online Service for Competitor Price Analysis
beeretail.io is an online service for analyzing competitor prices. As part of a team of 7 people, my tasks on this project included:
Developing the beta version of the service using the Laravel Framework and the Domain-Driven Design (DDD) approach.
Making minor changes to the parsing system using Python.
Optimizing the service's performance with the MySQL database, denormalization, index tuning in tables, and server parameter adjustments.
Configuring optimal performance for the Laravel Horizon queue service with Redis.
Within 4 months, the first working version of the product was released, which was subsequently significantly improved and included a database of over 50 million products and more than 5,000 service users.

The company developed a modern ecommerce SaaS platform for creating online stores.
My Role and Responsibilities:
As part of a team of 5 developers, my task was to design and develop a fault-tolerant and high-performance solution, and launch the first version within a short timeframe. My responsibilities included:
Server Infrastructure Management
Setting up and maintaining a fault-tolerant server infrastructure consisting of 10 servers: Linux, Nginx, PHP, MongoDB multi-server cluster, Redis multi-server cluster
Backend Development
Developing the backend of the main service using PHP 7.4 + MongoDB.
Developing the backend service for collecting statistics and analytics on website visits and sales using Java 8 + Spring Framework.
Deployment
Deploying the application to the multi-server infrastructure.
Project Outcome
Within 6 months, the first version of the product was developed and the first users were acquired.
Over the course of 4 years, the product was used by more than 1,000 online stores.
The web application stable handled an average of 50 requests per second, with peaks of up to 100 requests per second.

To expand the range of services offered, the company needed to provide hosting services.
My task was to ensure the technical capability to provide hosting services.
To accomplish this task, my responsibilities included:
- Selecting the necessary server hardware
- Installing servers in the data center
- Configuring and installing the required software: Linux, MySQL, Apache, PHP, Hosting Admin panels
- Maintaining system operability
- Responding to incidents: hardware failures, hacker attacks, DDoS attacks
- Scheduled software updates

- Mentoring for another system administrators
During my tenure, the number of hosting clients reached over 200, and the company was able to generate additional revenue from this source.