Іван

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Ivan Shamshur ​
Fullstack Engineer | SaaS Architect | React & PHP Expert

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General

Experienced developer focused on creating scalable SaaS solutions from scratch.
My strength lies in designing complex systems: from high-performance databases
(MySQL, ClickHouse) to interactive interfaces on React. I have practical experience
in optimizing high-load systems (caching, queues, big data analytics) and
integrating modern AI solutions (GPT/Gemini). In my work, I value code cleanliness,
architectural soundness, and a focus on the end business metrics of the product.

I know how to turn ideas into working, scalable products.

TECHNICAL SKILLS

Core Stack

●​ Frontend: React, JavaScript (ES6+), Vite, React Query, React Hook Form,
i18next, LESS/CSS.
●​ Backend: PHP 8+, Yii2 (MVC), REST API Design, Service Layer Architecture.
●​ Database: MySQL (Optimization, 3NF), ClickHouse (OLAP/Analytics),
JSON-fields.

Infrastructure & DevOps

●​ Cloud & Storage: AWS S3, CloudFront (CDN), CloudFlare.
●​ Caching & Queues: Redis, Memcached, Message Queues (Background Jobs).
●​ Tools: Docker, Docker Compose, Git, Composer, NPM/PNP.

Advanced & Integrations

●​ AI: OpenAI (ChatGPT) API, Google Gemini API integration.
●​ Real-time: Server-Sent Events (SSE).
●​ Math & Logic: mathjs (complex formulas), Logical branching algorithms.
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Work experience
QuizLead.io​
Founder of QuizLead
02.2025 – Present

A multifunctional SaaS quiz builder for marketing and education. Led the full-cycle
product development from scratch: from architectural design to deployment and
ongoing support.

TECH STACK: React (Vite), PHP (Yii2), MySQL, ClickHouse, Redis, Memcached,
Docker, AWS S3, CloudFront.

KEY ACHIEVEMENTS & RESPONSIBILITIES:

BACKEND & DATABASE ENGINEERING

●​ Architectural Design: Engineered the MySQL database schema following 3NF
principles, ensuring data integrity and high system performance.
●​ Reduced primary database load through multi-level caching (Memcached &
Redis).
●​ Optimized "heavy" queries using Slow Query Log and EXPLAIN; improved data
retrieval via composite indexes and JOIN refactoring.
●​ Implemented ClickHouse to enable real-time processing of millions of events
and conversion funnel building.
●​ Utilized MySQL JSON fields for flexible storage and implemented real-time
updates via Server-Sent Events (SSE).

FRONTEND & LOGIC

●​ Developed a visual builder featuring question branching (logic jumps), a scoring
system, and a dynamic price calculator (mathjs).
●​ Established a modern build process with Vite, React Query for state
management, and React Hook Form.
●​ Implemented full multi-language support (4 languages) using i18next.

INTEGRATIONS & INFRASTRUCTURE

●​ Designed a REST API and integrated Generative AI (Gemini, ChatGPT) to
automate quiz content generation.
●​ Cloud Storage: Configured media storage on AWS S3 with CloudFront
(CDN) for low-latency delivery.
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●​ Developed connections with external CRM systems and messengers via
background queue processing.
●​ Established local development environment via Docker and managed
deployment to dedicated servers.

FINTECH & PAYMENTS

●​ Architected and implemented a secure billing engine from scratch, handling
subscriptions, invoices, and transaction logs.
●​ Integrated Stripe and PayPal for seamless fiat transactions, including
webhooks handling and automated refund logic.

FormDesigner.pro​
Founder of QuizLead
01.2013 – Present

FormDesigner is a versatile web-based tool designed to create professional online
forms of any complexity. It focuses on flexibility and deep customization, allowing
users to build everything from simple contact forms to complex calculators and
booking systems without writing a single line of code.

SeoPult​
Yii developer
12.2012 – 02.2016​
​
LinkUp.ua​
Yii developer
03.2011 – 12.2012

Intraweb Design​
PHP developer
05.2009 – 03.2011
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Education

Donetsk National Technical University​
Specialist degree in engineering · (2003 - 2007)