Sergei is available for hire
Hire SergeiSergei Ponkrashin
Verified Expert in Engineering
Full-stack Web Developer
Location
Saint Petersburg, Russia
Toptal Member Since
April 4, 2022
Sergei has been working in software development since mid-2000. Throughout this time, he has successfully completed a wide range of software, from standalone desktop applications and Windows services to rich web applications and SPAs. Sergei can understand and transform complex business requirements into software, ensuring applications are delivered on time and are according to specifications while being scalable, performance-optimized, and maintainable.
Portfolio
innRoad
.NET, C#.NET, JavaScript, React, ASP.NET MVC, ASP.NET Core, C#, .NET Core...
Self-employed
ASP.NET, ASP.NET Core, Angular, TypeScript, Web Development, SQL...
Velocity Data Systems LLC
.NET, C#.NET, JavaScript, .NET 4, ASP.NET, LINQ, Full-stack, Front-end...
Experience
Availability
Full-time
Preferred Environment
Windows, JetBrains Rider, Visual Studio, Visual Studio Code (VS Code), Slack, Jira, Git
The most amazing...
...project I've ever developed was a medical solution that processes a massive amount of data from all over the world to help create new vital drugs.
Work Experience
Senior Full-stack Developer
2022 - 2024
innRoad
- Implemented a large number of features and fixed a significant number of bugs in different React applications, which increased users satisfaction.
- Integrated Stripe payment capabilities into the React application, which gave users the ability to pay for hotel stays directly on the site.
- Fixed many bugs in legacy applications, extending their lifecycle without the need for a complete rewrite.
Technologies: .NET, C#.NET, JavaScript, React, ASP.NET MVC, ASP.NET Core, C#, .NET Core, Full-stack, Full-stack Development, TypeScript, Web Development, Microsoft SQL Server, PostgreSQL, HTML, Git, Single-page Applications (SPA), CSS, APIs, REST APIs, HTTP REST, HTML5, ASP.NET Core MVC, Databases, Web Applications, ORMLite, Kibana, Stripe, Stripe API, Stripe Payments, Stripe Connect API, jQuery, LINQ, Next.js, Front-end, User Interface (UI), IIS, Redux, Back-end Development, Front-end Development, MongoDB, SCSS
Senior Full-stack Developer
2021 - 2023
Self-employed
- Developed a web application that automates warehouse routing jobs and reduces the number of mistakes made by warehouse staff, resulting in savings of thousands of person-hours.
- Built a web application that helps warehouse staff handle barcodes by automating their printing based on database information, significantly cutting down on the number of mistakes.
- Created CI/CD pipelines to deliver a working solution to a customer in several minutes.
- Covered all back-end code with tests for better quality control during development.
Technologies: ASP.NET, ASP.NET Core, Angular, TypeScript, Web Development, SQL, Background Jobs, ASP.NET Web Forms, JavaScript, CI/CD Pipelines, Single-page Applications (SPA), CQRS, Jira, .NET, C#.NET, C#, .NET Core, HTML, CSS, CSS3, Figma, APIs, API Integration, Full-stack, Architecture, Web Applications, Web Application Architecture, Technical Leadership, Entity Framework, LINQ, GitHub, Back-end, REST APIs, Scrum, Databases, Bootstrap, Razor, ASP.NET Razor, RxJS, Reactive Programming, Full-stack Development, CSS Selectors, .NET 4, HTTP REST, SQL Server 2016, HTML5, ASP.NET MVC 5, Ajax, Git, ASP.NET Core MVC, Front-end, User Interface (UI), IIS, Back-end Development, Front-end Development, SCSS
Full-stack .Net Developer | Data Services Consulting Firm
2022 - 2022
Velocity Data Systems LLC
- Fixed bugs and added new features in existing ASP.NET Web Forms applications.
- Helped client configure Git repositories for the projects.
- Handled and improved the application deployment processes.
Technologies: .NET, C#.NET, JavaScript, .NET 4, ASP.NET, LINQ, Full-stack, Front-end, User Interface (UI), IIS, Back-end Development
Full-stack Developer
2022 - 2022
Self-employed
- Developed a job board app that allows managers and employees to create job vacancies and apply to them.
- Integrated the application with an existing system to convert applications to vacancies and actual job contracts.
- Tracked and fixed features and bugs using GitHub as an issue tracker.
Technologies: ASP.NET Core, Angular, C#, .NET, Full-stack, TypeScript, Web Development, Microsoft SQL Server, HTML, Git, Single-page Applications (SPA), Identity Server, C#.NET, .NET Core, CSS, CSS3, APIs, Architecture, Web Applications, Web Application Architecture, Entity Framework, LINQ, GitHub, Back-end, REST APIs, Databases, RxJS, Reactive Programming, Full-stack Development, CSS Selectors, HTTP REST, SQL Server 2016, HTML5, ASP.NET Core MVC, Front-end, User Interface (UI), IIS, Back-end Development, Front-end Development, SCSS
Team Lead
2021 - 2022
JSC Arcadia
- Led a team of 5-10 developers, QA, and DevOps successfully completing several major releases and many intermediate stages of various projects without missing deadlines.
- Mentored junior and mid-level developers and helped some people to grow from junior to senior developers.
- Developed MVP for garbage truck sharing based on microservices architecture hosted on AWS.
- Created a RESTful API for live video streaming using SignalR technology.
- Developed a centralized user provisioning system, which simplified the user management process for a large number of distributed applications.
- Improved CI/CD configurations of various applications, which reduced the time for delivering changes to the end users to a couple of minutes.
- Covered most of the code with tests for better quality control during development.
Technologies: Agile Software Development, ASP.NET, ASP.NET Core, ASP.NET MVC, Angular, AngularJS, Microsoft SQL Server, SQL, Git, Hangfire, TypeScript, JavaScript, ASP.NET Web API, Jira, D3.js, SAML, CI/CD Pipelines, Single-page Applications (SPA), CQRS, SignalR, Node.js, .NET, Web Development, C#.NET, C#, .NET Core, HTML, CSS, CSS3, APIs, API Integration, Full-stack, Amazon Web Services (AWS), Architecture, Web Applications, Web Application Architecture, Technical Leadership, Entity Framework, LINQ, GitHub, Back-end, REST APIs, Serverless Architecture, Scrum, Databases, Firebase, Bootstrap, Razor, ASP.NET Razor, Firebase Realtime Database, Firebase Authentication, NoSQL, RxJS, Reactive Programming, Full-stack Development, CSS Selectors, jQuery, .NET 4, HTTP REST, SQL Server 2016, HTML5, ASP.NET MVC 5, Ajax, Windows Presentation Foundation (WPF), Windows Desktop, Windows App Development, ASP.NET Core MVC, Front-end, User Interface (UI), Data Visualization, IIS, Back-end Development, Front-end Development, Leadership, SCSS
Leading Full-stack Developer
2016 - 2021
JSC Arcadia
- Became a leader of a small team of developers and together with the team completed several important releases and many intermediate stages of the project.
- Mentored junior and mid-level developers and helped some people grow from junior to senior developers.
- Developed an application with rich and powerful visualization of huge amounts of data, which helped users reduce routine operations.
Technologies: ASP.NET, ASP.NET MVC, ASP.NET Core, Angular, AngularJS, Microsoft SQL Server, SQL, Git, Agile Software Development, PostgreSQL, Jira, JavaScript, ASP.NET Web API, D3.js, CI/CD Pipelines, Single-page Applications (SPA), CQRS, SAML, .NET, TypeScript, Web Development, C#.NET, C#, .NET Core, HTML, CSS, CSS3, APIs, API Integration, Full-stack, Architecture, Web Applications, Web Application Architecture, Technical Leadership, Entity Framework, LINQ, GitHub, Back-end, REST APIs, Scrum, Databases, Bootstrap, Razor, Stripe Connect API, Google Maps API, Azure DevOps, ASP.NET Razor, Firebase, Firebase Realtime Database, Firebase Authentication, NoSQL, RxJS, NgRx, Reactive Programming, Full-stack Development, CSS Selectors, jQuery, .NET 4, HTTP REST, SQL Server 2016, HTML5, ASP.NET MVC 5, Ajax, ASP.NET Core MVC, Front-end, User Interface (UI), Data Visualization, IIS, Back-end Development, Front-end Development, Leadership, Microservices, SCSS
Senior Full-stack Developer
2014 - 2016
JSC Arcadia
- Developed an application with rich and powerful visualization of huge amounts of data, which helped users to reduce routine operations.
- Created an application to automate the completion of medical research data with further statistical calculations.
- Created a hybrid application using AngularJS and Angular frameworks interacting with each other, which allowed smooth and incremental improvements to the existing application.
Technologies: ASP.NET, AngularJS, Microsoft SQL Server, SQL, Git, Agile Software Development, Jira, JavaScript, TypeScript, D3.js, SAML, ASP.NET Web API, Single-page Applications (SPA), CQRS, .NET, Web Development, C#.NET, C#, .NET Core, HTML, CSS, CSS3, APIs, API Integration, Full-stack, Architecture, Web Applications, Web Application Architecture, Entity Framework, LINQ, GitHub, Back-end, REST APIs, Scrum, Databases, Bootstrap, Razor, ASP.NET Razor, Full-stack Development, CSS Selectors, jQuery, .NET 4, HTTP REST, HTML5, ASP.NET MVC 5, Ajax, ASP.NET Core MVC, Front-end, User Interface (UI), Data Visualization, IIS, Back-end Development, Front-end Development, SCSS
Full-stack Developer
2011 - 2014
Megatec
- Participated in the development of systems for automating activities of tour operators and travel agencies.
- Reworked some modules of the main tour operator system, which led to a decrease of the number of complaints from users.
- Completely rewrote the web booking system where clients could book and pay for a tour.
Technologies: ASP.NET, JavaScript, Windows Forms (WinForms), ASP.NET Web Forms, Windows Communication Foundation (WCF), Windows Presentation Foundation (WPF), TFS, Microsoft SQL Server, ASP.NET MVC, .NET, SQL, Web Development, C#.NET, C#, HTML, CSS, CSS3, Full-stack, Architecture, Web Applications, LINQ, Back-end, Scrum, Databases, Razor, ASP.NET Razor, Full-stack Development, CSS Selectors, jQuery, .NET 4, HTML5, ASP.NET MVC 5, Ajax, Windows Desktop, Windows App Development, Desktop App Development, C#.NET WinForms, Front-end, User Interface (UI), Back-end Development, Front-end Development
Experience
Warehouse Management
A SPA application for warehouse routines automation.
I acted as a full-stack developer and created both back-end and front-end parts of the application. I communicated with a UI designer to integrate screens designs created in an external tool into the application.
This application significantly reduced the number of person-hours spent on routine duties like moving product pallets from one slot to another.
I acted as a full-stack developer and created both back-end and front-end parts of the application. I communicated with a UI designer to integrate screens designs created in an external tool into the application.
This application significantly reduced the number of person-hours spent on routine duties like moving product pallets from one slot to another.
Food Products Manufacturing Recipe Management
A SPA application for automation of food cooking on manufacturers.
I acted as a full-stack developer and created both back-end and front-end parts of the application. I also integrated with an external legacy database which was the source of truth for a previous version. I created a mocking factory to work with database-like data in environments where the database is not accessible.
This application allows food preparation to be more predictable and straightforward, with all exceptional cases processed in a user-friendly way.
I acted as a full-stack developer and created both back-end and front-end parts of the application. I also integrated with an external legacy database which was the source of truth for a previous version. I created a mocking factory to work with database-like data in environments where the database is not accessible.
This application allows food preparation to be more predictable and straightforward, with all exceptional cases processed in a user-friendly way.
Google and Facebook Ads Campaigns AI Optimization Tool
https://unyte.ai/platform/A SPA application that aims to control the budget of a large number of ads campaigns on Google and Facebook. The application uses AI to determine the required budget based on selected campaign user activities.
I was a full-stack developer and developed both the back-end and front-end parts of the application.
I was a full-stack developer and developed both the back-end and front-end parts of the application.
Realtime Video Streaming
An application created to perform live streaming from different devices like drones, quadcopters, and smartphones.
I was a back-end developer and created RESTful API services with real-time communication, which later were used to replace direct calls to the Firebase real-time database. I also developed an authentication server that replaces Firebase Auth and allows authenticating users by local Firebase accounts and third-party providers like Google or other customer-specific providers.
I was a back-end developer and created RESTful API services with real-time communication, which later were used to replace direct calls to the Firebase real-time database. I also developed an authentication server that replaces Firebase Auth and allows authenticating users by local Firebase accounts and third-party providers like Google or other customer-specific providers.
Tests Management System
A web application that is integrated into a legacy huge standalone Windows application. This approach allows improving and modernizing the legacy application to a contemporary one step-by-step, instead of doing this at once—with a risk of breaking everything.
I was a front-end developer but had to fix a communication mechanism from the Windows application side.
I was a front-end developer but had to fix a communication mechanism from the Windows application side.
Education
2006 - 2010
Bachelor's Degree in Computer Science
Astrakhan State Technical University - Astrakhan, Russia
Certifications
AUGUST 2013 - PRESENT
Microsoft Certified Professional
Microsoft
Skills
Libraries/APIs
LINQ, REST APIs, RxJS, Windows Forms (WinForms), SignalR, Node.js, D3.js, Entity Framework, NgRx, jQuery, React, Vue, Facebook Ads API, Google Ads API, Stripe Connect API, Google Maps API, Stripe, Stripe API
Tools
Git, Jira, GitHub, C#.NET WinForms, TFS, Firebase Authentication, Hangfire, Figma, Kibana
Frameworks
.NET, ASP.NET, ASP.NET Core, Angular, ASP.NET MVC, ASP.NET Web API, .NET Core, .NET 4, ASP.NET MVC 5, MVC Razor, ASP.NET Core MVC, AngularJS, ASP.NET Web Forms, Bootstrap, Razor, Windows Presentation Foundation (WPF), Telerik Kendo UI, ORMLite, Next.js, Redux
Paradigms
Agile Software Development, Web Application Architecture, Reactive Programming, Desktop App Development, CQRS, Scrum, Windows App Development, Microservices, Serverless Architecture, Azure DevOps
Languages
TypeScript, JavaScript, C#.NET, C#, ASP.NET Razor, SQL, HTML, CSS, CSS3, VB.NET, HTML5, SCSS, SAML, Delphi
Storage
Microsoft SQL Server, Databases, SQL Server 2016, PostgreSQL, Firebase Realtime Database, NoSQL, MySQL, MongoDB
Platforms
Windows Desktop, Firebase, Amazon Web Services (AWS)
Other
Web Development, Single-page Applications (SPA), APIs, API Integration, Full-stack, Architecture, Web Applications, Technical Leadership, Back-end, Full-stack Development, HTTP REST, Ajax, Front-end, User Interface (UI), Back-end Development, Front-end Development, CI/CD Pipelines, Background Jobs, Identity Server, CSS Selectors, Data Visualization, IIS, Leadership, Windows Communication Foundation (WCF), Artificial Intelligence (AI), Stripe Payments
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