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Sergei G.SG

Sergei G.

Senior Developer

€579/day
London, GB
8-15 years

Average response time: 1 hour

About Sergei

Senior Software Developer with 10+ years delivering high-traffic e-commerce and backend platforms. Expert in PHP (5-8)
and Go; design and build microservices and APIs (REST/GraphQL/gRPC) with Symfony, Laravel, Yii2, and CLI tooling.
Skilled across data and messaging, MySQL/Percona, PostgreSQL, MongoDB, Redis, Kafka with Avro, and in
containerisation and delivery using Docker, Swarm, Linux, Bash, and CI/CD. Champion of engineering quality (BDD/TDD
with Gherkin, PHPUnit, Codeception) and a proven team lead who collaborates closely with the frontend to ship secure,
scalable features.
  • Russian

    Native or bilingual

  • English

    Conversational

Remote only
Primarily works remotely

Experience

  • Self-employed
    Software Developer
    DIGITAL AND IT
    March 2026 - May 2026 (2 months)
    London, United Kingdom
    Founder & Software Engineer — Clean Plate Society

    Designed and launched a subscription-based iOS application that helps families encourage positive mealtime habits through achievement tracking and collectible rewards.

    Responsibilities included product design, software architecture, SwiftUI development, App Store monetization, subscription management with RevenueCat, App Store Connect configuration, TestFlight distribution, compliance management, and production deployment. Successfully navigated Apple's review process, implemented auto-renewable subscriptions, and delivered a fully operational consumer application from concept to public release.

    Technologies: Swift, SwiftUI, RevenueCat, StoreKit, App Store Connect, TestFlight, Git

    The app URL:
    Swift SwiftUI RevenueCat StoreKit TestFlight
  • OnBuy
    Senior PHP Developer
    E-COMMERCE
    March 2024 - Today (2 years and 3 months)
    London, United Kingdom
    Delivered and iterated on high-impact features for the marketplace platform, partnering closely with the frontend
    to scope and evolve APIs.
    Diagnosed and resolved critical performance bottlenecks for high-traffic marketplace pages, improving system
    uptime and response times under peak load.
    Stabilised and modernised legacy services and microservices (Laravel), prioritising and paying down technical debt
    to improve reliability and maintainability.
    Strengthened quality with automated tests and actionable regression notes; mentored peers through reviews and
    pair programming.
    Drove continuous delivery within Scrum ceremonies, improving flow and visibility across the team.
    Enhanced system resilience by implementing PubSub messaging patterns and DeadLetter queues to ensure reliable
    processing of asynchronous tasks.
    Leveraged Google Cloud Platform (GCP) to architect resilient backend monitoring and storage solutions, including
    centralised logging, real-time queue health monitoring, and scalable cloud storage.
    PHP MySQL Docker API REST Laravel
  • self-employed
    Software Engineer
    DIGITAL AND IT
    November 2022 - March 2024 (1 year and 4 months)
    London, United Kingdom
    Built a ChatBot microservice bridging Facebook and Telegram using Domain-Driven Design (Clean Architecture);
    designed clear interfaces and documentation. For customers who prefer reading information using Telegram. Stack:
    PHP, Docker, PostgreSQL, Doctrine. GitHub: Developed a meal-planner API using Domain-Driven Design (Clean Architecture) Stack: in Go (Go-Chi), MongoDB
    and Redis; exposed REST, GraphQL, and gRPC (MVP); containerised with Docker and instrumented with Logrus. For
    customers who want to know what they need to buy for the next few weeks and how they can cook it. GitHub:
    PHP Docker Doctrine GoLang DDD

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Education

  • Bachelor
    Synergy
    2019
    It was the state university in Moscow.

Certifications

Skill set

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