About Me

Hello, I'm Aleksey Maltsev

Senior Software Engineer

I've been programming for fun and profit since 2014, focusing on distributed systems and highload applications. My main stack is C#, Kotlin, and TypeScript, but I'm also proficient in Go.

Fun fact: I was born on the 11th of April, just a day before Yuri Gagarin's flight. Poehali! 🚀

aleksey@maltsev.space GitHub LinkedIn

My Journey

August 2020–present • Infobip • Senior Software Engineer

Infobip is a global Communications-Platform-as-a-Service (CPaaS) provider offering APIs for messaging, voice, video, and contact center services.

Led a zero-downtime migration of 3 microservices and approximately 1 TB of data from a MongoDB replica set to a sharded cluster
Improved platform performance by optimizing bottleneck queries, reducing p95 latency by 5 to 10 times
Designed and implemented a fault-tolerant architecture in Kotlin and C# for 4 real-time audience segmentation microservices, processing ~10,000 events per second
Delivered a segmentation feature that replaced an external product via "dogfooding".
Developed internal CLI and CI/CD tools, replacing manual work with automation

C#KotlinGoTypeScriptReactASP.NETSpring BootKafkaMongoDB

August 2019–August 2020 • Veeam Software • Software Engineer

Veeam Software is the global leader in backup and data recovery solutions for virtual machines, serving over 550,000 customers across more than 30 countries.

Integrated a RESTful microservice connecting Veeam Backup for Microsoft Azure with Veeam Backup & Replication using C#, .NET Core 3.1, ASP.NET Core, and Swagger-documented APIs
Engineered an event-driven pipeline ensuring sub-1-second for daily entity updates, maintaining eventual data consistency through SignalR, PostgreSQL, and Entity Framework Core
Implemented a real-time notification center in the web UI, reducing status-check time from 6 clicks to a single click via React, TypeScript, and SignalR

C#AzureTypeScriptReactASP.NETPostgreSQL

October 2017–August 2019 • Kontur • Software Engineer

Kontur is Russia's second-largest SaaS provider, offering 70+ cloud services for accounting, compliance, and e-government to 2.2 million business customers in Russia and abroad.

Delivered 5 enterprise features for Kontur Extern using C#/.NET and React, supporting over 800,000 B2B clients
Refactored the monolithic backend by replacing global context with scoped services in ASP.NET, enabling batch processing of 1,000+ documents per request
Migrated legacy JavaScript UI to React, Redux, and TypeScript, cutting feature delivery time by 6 to 10 hours per task

C#.NET FrameworkTypeScriptReactASP.NETWCFMSSQL Server

April 2018–December 2019 • Freelancing • Software Engineer

Independent contractor working on mobile application development.

Optimized the rendering pipeline of a Xamarin.Forms Android app, increasing frame rate from 30–35 fps to a steady 55–60 fps (+70%), significantly enhancing user experience
Implemented custom caching and full offline mode using Realm database, reducing remote API calls and improving load times
Refactored legacy code to clean MVVM architecture, shortening feature lead time and boosting unit-test coverage to nearly 90%

C#XamarinAndroidRealmMVVM

October 2015–August 2017 • PRO IT • Software Developer

PRO IT is a Russian software company developing web-based electronic document workflow systems for government agencies, employing over 100 staff.

Engineered a push-based scheduling daemon, reducing client polling traffic by approximately 80%
Developed self-service admin panels, enabling support staff to resolve ~90% of common tickets without engineering involvement
Refactored a jQuery codebase to Knockout.js (MVVM), halving front-end defect rates and accelerating feature delivery
Optimized heavy LINQ queries in Entity Framework for Oracle, cutting average latency from 1 minute to 4–5 seconds

C#.NET FrameworkASP.NETReactMSSQL ServerLINQ

December 2014–October 2015 • Kai Development • Junior Software Engineer

Kai Development is a Russian software engineering studio specializing in web-based business and government automation. Since 2007, the company has delivered 45+ projects, including the legal-tech spin-off XSUD for Russian ministries and major corporations.

Developed a jQuery-based WYSIWYG admin panel for the XSUD project blog and introduced semantic versioning of post markup in ASP.NET MVC, reducing publishing time and increasing click-through rates by approximately 35% within 4 months
Designed and launched an offline-capable Android app for the Safe-Childhood Map project within 2 months
Refactored CPU-heavy business logic into parameterized Microsoft SQL Server stored procedures, reducing p95 latency from 30 seconds to under 5 seconds

C#.NET FrameworkPHPJavaScriptJavaAndroidMSSQL ServerTransact-SQL

Professional Interests

Personal Projects

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CarryFit

An online tool that helps travelers check if their carry-on luggage meets size requirements for different airlines worldwide. Simply enter your bag's dimensions to instantly see which of 150+ airlines will accept it as cabin baggage.

SvelteKit TailwindCSS TypeScript

Visit Site

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MongoTransit

A tool for automatic replication of documents between MongoDB clusters. Supports iterative transfers, sharded collections, and configurable synchronization parameters, making it ideal for database migrations and data synchronization tasks.

C# MongoDB

View on GitHub

Hobbies & Interests

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Reading

I enjoy reading books on technology, science, and other topics to learn new things.

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Rock Climbing

I like rock climbing to stay active and enjoy the outdoors.

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Mountain Skiing

I enjoy mountain skiing in the winter.

Programming Challenges

I enjoy participating in coding challenges to sharpen my skills and explore new programming concepts.

Advent of Code

I've completed multiple years of Advent of Code challenges:

2023 2022 2021 2020 2017

LeetCode

I practice algorithmic problem solving on LeetCode to improve my coding efficiency and understanding of data structures.

View Solutions