Sergey Kuzminich

Senior Software Engineer | AI Engineering
Brest, BY.

About

Senior Software Engineer with 15+ years of experience specializing in backend systems, API architecture, and scalable AI-powered software delivery. Expert in AI engineering, agentic workflows, and LLM-powered applications using Python, FastAPI, and LangChain, I design and implement robust, scalable solutions.

Proven ability to take full ownership of the engineering lifecycle, from system design to deployment, across diverse environments including startups and remote international teams, ensuring high standards and rapid production delivery.

Work

AI Systems & Backend Architecture Project
|

Senior Software Engineer - AI Systems & Backend Architecture

Poland

Summary

Designed and implemented AI-powered software solutions and AI-assisted development workflows using modern LLM tooling and Python ecosystems to enhance sales processes and engineering productivity.

Highlights

Designed and implemented an MVP RAG platform for sales workflow automation, projected to improve sales-to-lead communication speed by 2x.

Built a scalable asynchronous modular monolith architecture with retrieval, caching, authentication, and prompt orchestration layers, designed for future microservices extraction.

Improved development workflows through AI-assisted practices, reducing prototyping time by ~3x, refactoring effort by ~2x, and documentation generation time by ~5x, with routine implementation tasks reduced by up to 5-10x.

Developed context engineering harnesses and prompt orchestration approaches, improving LLM response consistency and reducing unnecessary token consumption by ~25%.

Independently delivered and maintained Python-based web applications with lightweight user-facing interfaces (React-based), focusing on rapid iteration, maintainable architecture, and low operational overhead.

phlow
|

Senior Backend Engineer

London, England, United Kingdom of Great Britain and Northern Ireland

Summary

Contributed to architecture, scalability, and API platform development for a digital art startup product, pushing engineering boundaries and collaborating directly with CEO/CTO on an open-source development project.

Highlights

Expanded, implemented, and optimized a large API based on REST and JSON:API, significantly lowering response times.

Achieved 90% code coverage with easily maintainable functional tests, ensuring high software quality and reliability.

Created OpenAPI documentation for 90+ endpoints using reusable PHPStorm live templates, enhancing developer productivity and API usability.

Initiated migration to a microservices architecture to improve application scalability and maintainability.

Participated in both high- and low-level decision-making processes, experimenting with new technologies, development methodologies, and remote processes.

CHILICON IT SOLUTIONS GmbH
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Senior Web Developer

Berlin, Germany, Germany

Summary

Participated in SaaS product back-end web development, simplifying maintenance complexity of multiple modifications, and learning effective non-technical communication skills to drive project improvements.

Highlights

Deconstructed a monolithic application and refactored over 400 legacy classes, significantly improving code structure and maintainability.

Simplified environment building by successfully advocating for Docker adoption among the team, streamlining development workflows.

Minimized total merge conflicts by implementing Git Flow within the company, enhancing team collaboration and code integration efficiency.

Implemented easy-to-maintain localization for 4 languages across 6 projects with a partially common user interface, expanding market reach.

Simplified code maintenance by effectively communicating and selling the benefits of upgrading to non-technical stakeholders.

Cleoo.sg
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Senior API Developer

Berne, Switzerland, Switzerland

Summary

Developed APIs (web services) within a well-structured remote teamwork environment, transitioning expertise from full-stack development to specialized API building.

Highlights

Successfully transitioned from full-stack development to specialized API building, enhancing expertise in web services.

Introduced Docker to the development workflow, improving environment consistency and deployment efficiency.

Gained extensive experience in building robust remote processes and agile methodologies within a startup culture.

Cultivated strong code review practices, significantly improving code quality and team collaboration.

Learned and applied best practices for API building, ensuring robust and scalable service development.

Freelance
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Freelance Senior Software Engineer

Summary

Led full software development lifecycle for diverse projects, growing into a senior role with enhanced problem-solving and analytical skills across e-commerce and CRM systems, while building and managing a small development team.

Highlights

Built and managed a small team consisting of 2 developers and 1 quality assurance engineer, overseeing project delivery and quality assurance.

Developed and implemented remote processes for priority setting, code quality control, troubleshooting, security, and performance management.

Managed production servers on Linux, ensuring continuous operation and high availability.

Conducted comprehensive business and requirements analysis, collected user stories, prepared roadmaps, and estimated costs for projects.

Gained expertise in SEO and digital marketing strategies, contributing to project visibility and client success.

G2X ItWorks Antalika
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Junior/Middle Developer

Belarus

Summary

Progressed from junior to middle+ developer, transitioning from Java to PHP, and taking responsibility for software design of web applications while improving communication and conflict resolution skills.

Highlights

Successfully transitioned from Java to PHP development, expanding technical versatility and project capabilities.

Managed direct customer communication, task estimation, and project planning, enhancing leadership and client management skills.

Developed proficiency in SQL (MySQL) and database management, crucial for robust web application development.

Gained hands-on experience with core web technologies including JavaScript, jQuery, Bootstrap, AJAX, CSS, HTML (HTML5), and XML.

Applied Object-Oriented Programming principles to design and develop scalable and maintainable web applications.

Education

Belarusian State University of Informatics and Radioelectronics
Minsk, Belarus

Bachelor of Science

IT

Languages

Russian

Native

Belarusian

Native

Polish

Conversational

English

Fluent

Certificates

Kubernetes for developers

Issued By

Slerm

Stratoplan Team Lead 101

Issued By

Stratoplan

Zend Certified PHP Engineer

Issued By

Zend

Maching Learning & Data Analysis

Issued By

Coursera

Skills

AI & Machine Learning

AI Engineering, Agentic AI Development, LLM Applications, RAG (Retrieval-Augmented Generation), AI-Assisted SDLC, Vector Databases, Embeddings, Claude Code, LLMs.

Backend Development

Software Architecture, API Architecture, Scalable Backend Systems, REST, Microservices, Modular Monolithic Architecture, System Design, Django, FastAPI, Object-Oriented Programming.

Frontend Development

React, jQuery, Bootstrap, AJAX, CSS, HTML, HTML5.

DevOps & Cloud

Docker, Kubernetes, Cloud Infrastructure, CI/CD Pipelines, Linux.

Tools & Methodologies

Cursor, Claude Code, IntelliJ IDEA, Git Flow, Agile.

Business & Product

Product Engineering, Digital Marketing, Business Analysis, Requirements Analysis, Project Planning.

Soft Skills

Full Ownership, Analytical Skills, Team Leadership, Conflict Resolution, Problem Solving.

Programming Languages

Python, JavaScript, PHP, Java, MySql.