Sergey Mikolaitis
Avalonia Developer, Product Owner, Team Lead
I build fast desktop products, improve performance, and solve difficult technical problems in real systems. My strongest area is cross-platform .NET desktop development with Avalonia, but I also work deeply with ASP.NET, Entity Framework, PostgreSQL, WebSockets, pipes, profiling, dump analysis, and multithreaded bug fixing.
I like making software simpler, faster, and easier to ship. That often means zero-allocation refactoring, architecture cleanup, and removing bottlenecks that slow both the product and the team.
About me
I have more than 14 years of experience in software engineering. I enjoy owning both product and technical responsibility: leading teams, reviewing architecture, mentoring developers, improving delivery processes, and still taking on the hardest implementation work myself.
I am comfortable in lead roles where I need to combine hands-on engineering with planning, prioritization, and communication across development, QA, and product.
For cross-platform work and testing, I keep macOS, Linux, and Windows machines in regular use.
Skills
Core strengths
AvaloniaUI, WPF, MVVM, .NET 6+, C#, Performance Tuning, Zero-Allocation Optimization, Multithreading, Concurrency Debugging, WebSockets, LINQ, TPL, JSON, SVG, XML, Skia, Clean Code, Refactoring
Strong working knowledge
ASP.NET, Entity Framework, SignalR, PostgreSQL, MsSql, Sqlite, LiteDB, S3, CDN, DNS, Git, Linux, MacOS, REST, Memory Dump Analysis, OpenCode, LLM, MCP, MsStore, AppStore
Leadership and product
Scrum, Agile, Code Review, Team Leadership, Product Ownership, Decision-Making, Strategic Vision, Development Process Design, People Management, Team Management, Technical Documentation, Product Quality Ownership, Requirements Management, Technical Debt Management
Additional experience
AWS, Protobuf, Objective-C, Docker, WASM, Pipes, WinAPI, Continuous Delivery, Continuous Integration, Shaders, NuGet, Nginx
Earlier experience
JS, HTML, CSS, PHP, SQL, Sharepoint, Oracle, GraphQL, FFMPEG, VLC, OpenGL, DirectX, C, C++, WCF, ADO.NET, WinForms, UWP, IIS, Lua, Java, SOAP
Familiar technologies, no production experience
Apache Kafka, Prometheus, ClickHouse, RabbitMQ, MongoDB, gRPC, Grafana, Kubernetes
Experience
Icons8
Team Lead, Product Owner
Feb 2019 - Apr 2026
Led a startup-style team of 10-12 people and combined several roles at once: lead developer, team lead, scrum master, and product owner.
Key results:
- moved a large product from WPF to Avalonia for cross-platform delivery
- made Lunacy one of the first serious Avalonia products shipped in the App Store
- participated in the first major Avalonia WASM release for a production application
- implemented GPU rendering and major performance improvements in a previously slow application
- owned architecture, technical decisions, code review, and development process
- contributed hundreds of product features and many complex bug fixes
- worked with NativeAOT-related direction and performance-sensitive engineering
Main product: Lunacy
360bound
Lead .NET Developer
Jul 2018 - Dec 2019
Led a 4-person development team, estimated and scheduled work, distributed responsibilities, improved communication with management, and accelerated the team's development process. I was responsible for project structure, XAML UI, complex algorithms, profiling, research, and the most difficult components.
Earlier at the same company, I also worked on a Windows application for creating advanced surveys in a PowerPoint-like designer and exporting them to popular survey engines.
Arkadium
.NET Developer / PreSenior .NET Developer
Jan 2016 - Dec 2017
Worked on Microsoft Casual Games titles including Solitaire, Mahjong, Jigsaw, Sudoku, and Minesweeper. Focus areas included crash dump analysis, bug fixing, optimization, multithreaded tooling, and an ads module shared across multiple games. I also improved Mahjong startup and page-loading speed by up to 5x.
Related project background: Microsoft Casual Games
Laitis
Founder, Developer
Sep 2013 - Feb 2020
Built Laitis from idea to product as a solo founder and engineer. The project included the desktop app, installer, browser extensions, website, Web API, database, security, localization, analytics, support, profiling, testing, and distribution.
Laitis is a Windows application for voice control and text dictation.
Related project background: Laitis
FlexBricks
.NET Developer
Apr 2012 - Dec 2016
Worked on several business and media products, including WPF applications, an OS X application, an internal company website, an inventory system, and software for a 360 video workflow with 16 cameras around a scene.
Related project background: Orbital Video
TOP Computer Academy
.NET Teacher
Jan 2012 - Sep 2014
Taught C#, Windows Forms, WPF, system programming, network programming, MS SQL, ASP.NET, ADO.NET, and WCF.
Education
Master's degree in Mathematics and Computer Science.
Read full education background
Recommendations
I have over 15 recommendations from teammates, managers, and QA colleagues who worked with me on real products over multiple years.