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.

Designed and implemented fault-tolerant architecture in Kotlin and C# for 4 real-time audience-segmentation services, processing up to 50,000 events per second. One delivered feature replaced an external product through internal dogfooding.
Led a zero-downtime migration of 3 microservices and ~1 TB of data from a MongoDB replica set to a sharded cluster.
Improved platform performance by optimizing MongoDB query p95 latency and redesigning the leader-election algorithm, achieving a 5–10× improvement in key technical metrics.
Developed internal tools in C# and Go to automate maintenance and troubleshooting.

C#KotlinGo (Golang)TypeScriptReactASP.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.

Built a RESTful integration between Veeam Backup for Azure and Veeam Backup & Replication using C#, ASP.NET Core, and Swagger-documented APIs.
Implemented a real-time notification center in Veeam Backup for Azure using WebSockets.
Engineered an event-driven data synchronization pipeline handling thousands of daily entity updates, ensuring eventual consistency between two major products.

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 for B2B clients.
Refactored the monolithic backend by replacing the global context with scoped services in ASP.NET, enabling batch document processing per request.
Migrated a legacy JavaScript UI to React, Redux, and TypeScript.

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 improving the user experience.
Implemented custom caching and a full offline mode using the Realm database, reducing remote API calls and improving load times.
Refactored legacy code into a 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, with over 100 employees.

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 involving engineers.
Refactored a jQuery codebase to Knockout.js (MVVM), halving front-end defect rates and speeding up feature delivery.
Optimized heavy LINQ queries in Entity Framework for Oracle, cutting average query 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 for post markup in ASP.NET MVC, reducing publishing time and increasing click-through rates by ~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

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.

Svelte 5TailwindCSSTypeScript

HumbleHire

HumbleHire is a free, open-source CV builder that runs entirely in your browser. You keep one master CV with your whole history in it, branch a tailored copy for each job you apply to, and export a clean PDF to send.

Svelte 5TailwindCSSTypeScript

🔄

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

Hobbies & Interests

📚

Reading

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

🧗

Rock Climbing

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

⛷️

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