Сергей

Sergey Shishchenko
e-mail: [open contact info](look above in the "contact info" section)
@auctionsline (Telegram)
LinkedIn: [open contact info](look above in the "contact info" section)
PHP Developer & LLM-engineering (Claude code)
⚡ Laravel · Symfony · Microservices · DDD · API Integration

PROFILE PHP developer, specializing in fintech, trading infrastructure, and API integration. Proven track
record of architecting microservices-based platforms from scratch, designing high-throughput
data pipelines, and optimizing database performance for real-time applications. Experience with
Domain-Driven Design (DDD) – including strategic modeling (bounded contexts, ubiquitous
language) and tactical patterns (aggregates, value objects, domain events, repositories). Building a
scalable real-estate platform with LLM-powered features – combining AI with robust backend
systems. Adept at leading technical design, mentoring teams, and delivering production-grade
solutions for US-based product companies.

EXPERIENCE US IT Company (Real estate investments / LLM) 2023 – Present
PHP Developer – Backend Architecture & LLM engineering
▹ Architected a scalable real-estate web application, with Laravel & Symfony microservices orchestrated via
Docker.
▹ Designed, backend architecture, optimized queries, and implemented caching. LLM engineering with
Claude code.
▹ Development from the first commit.
Stack: Symfony · Laravel · PHP 8.2 · MySQL · PostgreSQL · ClickHouse · MongoDB · Redis · Docker · GitLab · LLM
APIs

US IT Company (DDD / Fintech) 2021 – 2023
PHP Developer – Arbitrage Systems & Crypto Exchange
▹ Built high-frequency crypto exchange platforms (spot, futures, options) from scratch, handling 1M+ daily
orders with sub-second matching engine latency.
▹ Implemented microservices-based architecture (Symfony, Laravel, RabbitMQ) achieving 99.95% uptime
and horizontal scaling.
Stack: Symfony · Laravel · PHP 8.1 · MySQL · PostgreSQL · MongoDB · Redis · RabbitMQ · Docker · GitLab ·
WebSocket

Ukrainian Company 2020
Full-Stack PHP Developer (Symfony)
▹ Built and maintained large-scale projects using Symfony framework.
▹ Designed databases, developed backend logic, and integrated frontend modules.
Stack: Symfony 3.2 · Doctrine · PHP 7.2 · PostgreSQL · Docker · Twig · Bootstrap · jQuery

Auction service (Fintech / DDD) 2019
Full-Stack PHP Developer
▹ Delivered a real-time auction platform with WebSocket-based bidding, supporting 5k+ concurrent users
during peak events.
▹ Designed database structure, implemented backend, and developed frontend UI.
Stack: Symfony 4.4 · Doctrine · PHP 7.2 · MySQL · Docker · Twig · Bootstrap · jQuery · WebSocket

TECH Languages & Frameworks
STACK PHP 8.2 / 7.4 Laravel Symfony JavaScript Node.js (basic)

Databases & Messaging
MySQL PostgreSQL ClickHouse MongoDB Redis RabbitMQ

DevOps & Tools
Docker / Compose Git / GitLab CI PHPUnit xDebug Postman Kubernetes (basics)

Architecture & Design
Microservices OOP / SOLID Event-Driven REST / GraphQL Doctrine ORM
API Integration (LLM, REST, WebSocket)

Frontend (basic-to-intermediate)
Twig Bootstrap jQuery HTML5 / CSS3

SOFT 🤝 Team Leadership 🗣️ Cross-functional Communication 🎯 Ownership & Accountability
SKILLS 🧩 Complex Problem Solving ⏳ Agile / Scrum 📈 Technical Mentoring
ADDITIONAL Entrepreneur (2016–2018) – founded and managed a small e-commerce venture.