Hi, I am Sergey Dolin, software developer with 25 years of experience in creating mobile, desktop and web applications with complex business logic, a modular structure, interacting with network infrastructure through various protocols.
Proficient in both lead and developer roles, with a proven ability to collaborate within teams and manage the full project lifecycle, including planning, CI/CD integration and long-term support.
I founded S4Y Solutions as a company specializing in B2B software development contracts. It also serves as an umbrella brand for publishing applications developed independently, not tied to specific clients.
Android development(Kotlin, Composer UI, Coroutines, Gradle)
90%
Web development (React, RxJS, TypeScript)
90%
Backend development (Node.js, Golang, Java)
90%
Cloud computing (Azure, GCP)
60%
Flutter development (BLoC, Provider)
60%
Scripting Languages (Python, Lua, R, PHP, Scheme, ActionScript)
60%
IOS development (Swift, Objective-C)
30%
ML (Tensorflow, TF Lite/LiteRT)
30%
Embedding systems, CGI/FCGI(C++, C)
30%
Test Automation (JUnit/Junit5, Mockito, Mocha, Chai, Jest, etc)
90%
DevOps (GitHub Actions, Bitbucket Pipelines, Azure DevOps)
90%
OSes (Unix, MacOS, Shell Scripting)
90%
Containers (Docker, Docker composer, K8s)
90%
Documentation (UML, C4, LaTeX, Markdown)
90%
Teamwork (Git, Jira, Azure DevOps, YouTrack)
90%
Databases (SQL, NoSQ)
80%
Project Management (PMBOK, Scrum, XP)
60%
* - percents correspond to level
** - colors correspond to relevance
For US based company adding to their Android application the new functionality related to the voice recognition and implementing text fusion search according to the recognized speech.
Personal projects:
For Serbia based Microsoft partner company, developing a desktop WPF application for the management of the datacenters infrastructure.
For US based company migrating Android application to Composer UI and Coroutines.
Personal projects:
For Russia/Serbia based Microsoft partner company, supporting GitHib Actions and AzDevOps infrastructure. Maintenance of a suite of GitHub Actions, as well as the development and maintenance of CI/CD pipelines for building, testing, and deploying Azure DevOps images to virtual environments. This includes provisioning and configuring tools for mobile development, ensuring they are correctly set up and capable of building any real-world Android and iOS applications, including those built with Xamarin and React Native.
For US based company developing the UI reach, Firebase backend Android and iOS applications for learning Arabic Language; React Admin panel; Gradle plugin to generate Flatbuffer assets.
For EU based company node.js GraphQL microservice for they crypto-currency exchange with Graphana monitoring.
Personal projects:
For Microsoft partner company, supporting MS AppCenter, Xamarin TestCloud infrastructure. Development and maintenance of the React/MobX frontend and Node.js/Express backend for the MS AppCenter. Development and maintenance of Android/iOS applications used for testing and evaluating MS AppCenter and Xamarin TestCloud. Tracking changes introduced with each release of Xcode, Xamarin and Android SDK. Maintenance CI/CD pipelines for the MS AppCenter and Xamarin TestCloud.
Personal projects:
Self-employed, developing Web-sites, web- and mobile applications for the clients from the USA, EU and Russia. Managing the team of the developers.
For IBM partner company, developing the Jira-plugins for in-house use. Migrated inherited z/OS Assembler code to Java. Developed the CGI/FCGI applications for the IBM mainframe.
Personal projects:
During the education and first years of employment, I worked in various fields, including PDP-11 assembler programming, 8086 assembler programming, Pascal, C, C++, Delphi, Paradox, Clipper, FoxPro, Basic, Oracle, DB/2, Novell Netware, Win32 API, DCOM, Corba, ActiveX, COM, MFC, ATL.