Open to opportunities

Сергей Калашников

@0001448

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Senior backend and fullstack architect building scalable systems and AI workflows.

Brazil

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What I'm looking for

I seek technical leadership roles where I can architect scalable systems, improve developer productivity with AI-assisted workflows, and deliver end-to-end solutions in a collaborative, engineering-driven culture.

I am a senior software engineer and solution architect with 10+ years in backend and 7+ years in frontend development, focused on building scalable systems and AI-assisted development workflows. I specialize in taking platforms from concept to production and maintaining high-availability microservices at scale.

At AliExpress I led architecture and development of a centralized HR platform, recruitment and onboarding systems, and 30+ production microservices, cutting administrative time and error rates dramatically. I have a track record of delivering high-impact internal tools such as corporate stores and automated workflows that improved process transparency and throughput.

As a software architect and lead developer, I migrated large monoliths to modern .NET versions, designed real-time chat and seat-map constructors, and implemented performance improvements up to 50–100× in critical workflows. I also contributed to fintech and SaaS products, driving migrations, refactors, and integrations with systems like Kafka, Redis, and PostgreSQL.

I mentor and evaluate candidates, lecture on C# and Python, and consistently emphasize maintainability, observability, and performance. I seek opportunities where I can architect resilient systems, improve developer productivity with AI-assisted tooling, and lead technical initiatives end-to-end.

Experience

Work history, roles, and key accomplishments

Current

Lead Developer

Current

AliExpress

Dec 2022 - Present (3 years 6 months)

Led architecture and development of centralized HR and internal platforms, automating workflows and unifying employee data to cut HR administrative time by up to 90% while maintaining 30+ production microservices for high availability.

C++ASP.NET Core Microservices PostgreSQL Kafka Entity Framework CI CD

Current

Software Architect

Current

Sirena-Travel

Jan 2022 - Present (4 years 5 months)

Architected and delivered core modules and client-specific systems, migrated a 30+ GB .NET monolith to .NET 8.0, and built real-time chat and seat-map features to launch production solutions within a year.

C++.NET Core React SignalR PostgreSQL Performance Optimization

Lead .NET Developer

Tinkoff

Mar 2022 - Dec 2022 (9 months)

Designed and implemented microservices to automate internal document and onboarding workflows, migrated core services from .NET Core 2.2 to .NET 6.0 with zero downtime and improved compliance and traceability.

ASP.NET Core PostgreSQL Kafka Redis Hangfire Microservices Performance Tuning

Full Stack Developer

Smartcat

Jun 2021 - Mar 2022 (9 months)

Developed B2C marketplace user profile management end-to-end and refactored legacy modules to Vue.js, improving maintainability and accelerating feature delivery.

ASP.NET Core MongoDB PostgreSQL TypeScript Vue.Js REST APIs Refactoring

Senior Full Stack Developer

Sirena-Travel

Feb 2018 - Jun 2021 (3 years 4 months)

Single-handedly developed core full-stack services for a B2B transport platform, implemented payment and real-time communication features, and optimized SQL queries to improve critical workflow performance by up to 50–100×.

ASP.NET Core PostgreSQL TypeScript React SignalR SQL Optimization Entity Framework

Guest Lecturer

National Research University Higher School of Economics

Sep 2017 - Jun 2021 (3 years 9 months)

Developed and delivered C# and Python course materials, supervised student projects and theses with an average supervision score of 9/10 and above-average teaching evaluations.

Teaching C++Python Curriculum Development Mentoring Academic Evaluation Student supervision

System Analyst

ThyssenKrupp Elevator

Sep 2015 - Feb 2018 (2 years 5 months)

Designed and developed web applications and refactored legacy Excel tools for resource management, maintained and optimized MS SQL databases, and produced technical documentation for delivered solutions.

ASP.NET SQL VBA Database Optimization Web Applications Technical Documentation

Education

Degrees, certifications, and relevant coursework

National Research University Higher School of Economics

Master of Business Informatics, Business Informatics

2017 - 2019

Completed a Master of Business Informatics program with coursework and projects focused on business-oriented information systems and applied software solutions.