Full Stack Developer (Node.js/ TypeScript)

Описание

Sergei Kolentsev
Backend Developer (Node.js / TypeScript / PHP / SQL)
Location: Tbilisi, Georgia
Phone: +995-558-91-0729
Email: kraken425@gmail.com
Telegram: @kraken700
LinkedIn: https://www.linkedin.com/in/sergey-kolentsev-3435bba5
SENIOR FULL STACK / BACKEND
ENGINEER
Node.js / TypeScript / PHP / SQL
PROFESSIONAL SUMMARY
Senior Backend / Full Stack Engineer with 10+ years of commercial software development
experience building enterprise, banking and high-load systems.
Strong backend expertise in Node.js, TypeScript, NestJS, Express.js, PHP, Laravel and
Symfony, with extensive experience designing RESTful APIs, integrating third-party
services, working with SQL databases and modernizing legacy systems.
Practical experience developing and migrating performance-critical services from
PHP/Symfony to Node.js/TypeScript/NestJS and Go. Strong background in PostgreSQL
and MySQL, including database design, data modeling, query optimization, indexes,
transactions and execution plans.
Experienced in distributed systems, microservice-oriented architecture, asynchronous
processing, Redis, RabbitMQ, Docker and CI/CD. Comfortable working with external APIs,
complex business integrations and production systems processing 100,000+ HTTP
requests per day.
Additional full-stack experience includes JavaScript, HTML and CSS and development of
internal web applications and administrative interfaces.
CORE COMPETENCIES
• Node.js
• TypeScript
• Express.js
• NestJS
• JavaScript
• RESTful APIs

• Third-Party API Integrations
• SQL
• PostgreSQL
• MySQL
• Data Modeling
• Database Design
• Query Optimization
• High-Load Systems
• Distributed Systems
• Microservices
• Asynchronous Processing
• Redis
• RabbitMQ
• Docker
• Git
• GitLab CI/CD
• Automated Testing
• Legacy System Modernization
• Performance Optimization
• OOP
• SOLID
• Design Patterns
PROFESSIONAL EXPERIENCE
Backend Developer / Senior Backend Engineer
NewMarcom — Projects for Openbank / Management Asset Company "Otkritie"
2019 — Present
Development and support of a high-load banking platform, including backend services,
APIs, integrations and gradual modernization of legacy systems.
Responsibilities
• Develop and maintain backend services using Node.js, TypeScript, NestJS, PHP,
Laravel and Symfony.

• Design and implement RESTful APIs and backend business services.
• Develop Node.js/TypeScript services and components for performance-critical
workloads.
• Participate in migration of selected legacy services from PHP 7.x/Symfony to
Node.js/TypeScript/NestJS and Go.
• Design and implement integrations with internal and external APIs.
• Work with third-party services and external financial systems.
• Design and optimize PostgreSQL and MySQL database structures.
• Develop and optimize complex SQL queries.
• Work with indexes, transactions and execution plans.
• Optimize database access and application performance.
• Implement caching strategies using Redis.
• Implement asynchronous business processes using RabbitMQ.
• Develop modular backend components and microservice-oriented services.
• Work with distributed systems and asynchronous processing.
• Containerize applications using Docker and Docker Compose.
• Maintain GitLab CI/CD pipelines.
• Participate in code reviews and technical discussions.
• Collaborate with analysts, QA engineers, DevOps and product teams.
Key Achievements
• Participated in modernization of a large PHP backend platform and migration of
performance-critical services to Node.js/TypeScript/NestJS and Go.
• Maintained and scaled production backend services processing more than 100,000
HTTP requests per day with 99.9% uptime .
• Improved application performance through SQL optimization, indexing and Redis
caching.
• Participated in architecture design for new backend services.
• Introduced asynchronous processing with RabbitMQ for business workflows.
• Developed Go components using goroutines, channels and worker pools for
concurrent processing.
• Participated in refactoring legacy components and transition toward modular and
distributed architecture.

Technologies
Node.js • TypeScript • NestJS • Express.js • Go • PHP 7/8 • Symfony • Laravel •
PostgreSQL • MySQL • Redis • RabbitMQ • Docker • Docker Compose • GitLab CI/CD •
REST API • Git
Backend Developer
NewMarcom — Projects for Management Asset Company "Otkritie"
2015 — 2019
Development of an investment management platform, backend services and integrations
with external financial systems.
Responsibilities
• Develop backend applications using PHP and Laravel.
• Design and implement REST APIs.
• Develop business modules and application services.
• Integrate external financial systems using REST and SOAP.
• Design database schemas for PostgreSQL and MySQL.
• Develop database migrations.
• Optimize SQL queries and database indexes.
• Work with transactions and database performance.
• Implement caching using Redis.
• Implement asynchronous processing using Laravel Queues and RabbitMQ.
• Apply Dependency Injection and common design patterns.
• Refactor and improve existing and legacy application components.
• Participate in architecture design of new application modules.
Key Achievements
• Developed core API modules for an investment management platform.
• Implemented integrations with external financial services.
• Improved database performance through SQL and index optimization.
• Participated in architecture design of new backend modules.
• Implemented asynchronous business workflows.
Technologies
PHP • Laravel • Slim Framework • PostgreSQL • MySQL • Redis • RabbitMQ • REST API •

SOAP • JWT • Composer • SQL • Database Migrations
Full Stack Developer
Informtrend
2012 — 2015
Development and support of internal corporate web applications and information systems.
Responsibilities
• Develop and maintain corporate web applications.
• Develop backend services and REST APIs.
• Develop web interfaces using JavaScript, HTML and CSS.
• Integrate applications with Active Directory.
• Implement role-based access control systems.
• Develop administrative interfaces.
• Integrate HR and KPI management systems.
• Maintain and improve existing applications.
Technologies
PHP • JavaScript • HTML • CSS • MySQL • REST API • Active Directory
TECHNICAL SKILLS
Node.js / TypeScript
• Node.js
• TypeScript
• Express.js
• NestJS
• JavaScript
• Node.js Event Loop
• Asynchronous Programming
• RESTful API Development
• API Design
• Third-Party API Integration
• External Service Integration

• Dependency Injection
• Modular Architecture
Web / Frontend
• JavaScript
• HTML5
• CSS3
• Web Application Development
• Administrative Interfaces
• REST API Integration
• Client-Server Architecture
Databases / SQL
• PostgreSQL
• MySQL
• MariaDB
• SQL
• Database Design
• Data Modeling
• Database Schema Design
• Database Migrations
• Indexes
• Query Optimization
• Execution Plans
• Transactions
• Views
• Stored Procedures
Architecture
• High-Load Backend Systems
• Distributed Systems
• Microservices
• Modular Architecture
• Asynchronous Processing

• Queue-Based Architecture
• Event-Driven Components
• Legacy System Modernization
• Performance Optimization
• API Integrations
• SOLID
• OOP
• Design Patterns
Messaging / Caching
• Redis
• Redis Pools
• Cache Tagging
• RabbitMQ
• Message Queues
• Asynchronous Processing
• Dead Letter Queues
• Worker Pools
Go / Concurrency
• Go (Golang)
• Goroutines
• Channels
• Worker Pools
• Mutex
• Concurrency Primitives
• Concurrent Task Processing
• Synchronization
Infrastructure / DevOps
• Docker
• Docker Compose
• Nginx
• Git

• GitLab CI/CD
• CI/CD Pipelines
• Composer
Testing
• PHPUnit
• Unit Testing
• Integration Testing
• API Testing
• Automated Testing
• CI/CD Test Execution
PHP
• PHP 7.x / 8.x
• Laravel
• Symfony
• Slim
• PSR-4
• PSR-12
• Strict Types
• Typed Properties
• Attributes
• Enums
EDUCATION
Moscow Financial and Law Institute
B.Sc. in Finance, 2009 — 2013
Bauman Moscow State Technical University (MSTU)
Engineer, Electronic Technologies, 1997 — 2003
LANGUAGES
English: B2 — Reading / Listening; B1 — Speaking / Writing. Comfortable working with
technical documentation, architectural materials and distributed engineering teams.
Russian: Native