Duy is available for hire

Duy Pham

Verified Expert in Engineering

Software Developer

Location

Hanoi, Vietnam

Toptal Member Since

October 29, 2019

Duy has 20+ years of software development experience using Microsoft's technology stack, primarily with .NET. He builds high-quality and high-performance back-end systems and creates web applications with good UX using modern frameworks like Angular or React. Duy's proactive and results-oriented with a love of not only writing but also removing code to ensure efficient, stable, and flexible software is delivered within the projected scope and budget.

Portfolio

ContractPodAi

SQL, .NET, ASP.NET Web Forms, Vue, JavaScript, jQuery, .NET 5, .NET 6, Docker...

SecureSheet Technologies, LLC

Visual Basic .NET (VB.NET), .NET, XML, Microsoft Excel, OpenXML...

Exemplar Human Services, LLC

.NET, APIs, Architecture, Project Consultancy, SlickGrid, JavaScript, jQuery...

Experience

SQL - 20 years C# - 17 years Agile - 12 years ASP.NET MVC - 8 years ASP.NET Web API - 8 years React - 3 years Blazor - 3 years .NET Core - 3 years

Availability

Part-time

Preferred Environment

Agile, Visual Studio, .NET, C#, Windows, GitHub, Visual Studio Code (VS Code)

The most amazing...

...thing I've contributed to is an eCommerce platform where I can work with different modern technologies to help with optimization, stabilization, and extension.

Work Experience

.NET Engineer - ASP.NET WebForms

2019 - PRESENT

ContractPodAi

Maintained and developed ContractPodAi's client-specific features in both the legacy cognitive version and the new cloud version of the product.
Optimized the client product (SQL, back end with .NET, and front end with Vuex) for better stability and performance in general and for specific modules such as approvals, workflows, legal intake forms, etc.
Consulted and proposed technical solutions and architecture for different problems and modules.
Architected and built a highly available and scalable auditing system for the whole application using .NET Core, Azure Service Bus, and Azure Container Instances.

Technologies: SQL, .NET, ASP.NET Web Forms, Vue, JavaScript, jQuery, .NET 5, .NET 6, Docker, Containerization, REST APIs, Azure Blob Storage API, Azure Service Bus, Bitbucket, CI/CD Pipelines, Azure Cosmos DB, MongoDB, Azure Container Instances

Visual Basic Developer

2019 - PRESENT

SecureSheet Technologies, LLC

Used Open XML and VB.NET to develop an efficient and fast Excel reader that provides a highly structured Excel object model to help manipulate Excel workbooks easily, even with large Excel files.
Developed a simplified Excel Writer to effectively create an Excel workbook with almost all basic features such as named ranges, custom formatting, themes, formulas, cross references, data validations, charts, comments, protections, etc.
Developed a tool using .NET Core and C# to communicate with Amazon S3 service to backup data on a daily basis and send backup status email notifications.
Developed a tool to parse Excel formulas quickly and effectively using VB.NET.

Technologies: Visual Basic .NET (VB.NET), .NET, XML, Microsoft Excel, OpenXML, Amazon S3 (AWS S3), C#, .NET Core

.NET Consultant

2023 - 2023

Exemplar Human Services, LLC

Helped the client develop an internal module to manage their clients' organizational employees and their managers, together with organizational report subscriptions.
Integrated hybrid signing ceremony with DocuSign into their client-facing application, which supports both embedded and standard DocuSign signing flows. Integration was done using C#, REST APIs, and OAuth 2 to communicate with DocuSign API.
Enhanced the existing web page using SlickGrid control to allow the manipulation of both subordinate managers and employees together with their hierarchical report subscriptions using JavaScript, jQuery, and HTML/CSS.
Optimized performance of back-end ASP.NET Core handler methods (web methods) using LINQ with Entity Framework Core.

Technologies: .NET, APIs, Architecture, Project Consultancy, SlickGrid, JavaScript, jQuery, ASP.NET Core, Web Methods, Entity Framework Core, CSS, HTML, LINQ, OAuth 2

Full-stack Developer

2022 - 2022

Exemplar Human Services, LLC

Helped the client optimize and enhance their internal tool modules to manage organizational report subscriptions for their clients and internally.
Integrated SlickGrid control into the web application using JavaScript and jQuery, which communicates with the back end using web or handler methods in ASP.NET Core.
Refined and optimized LINQ queries (used with Entity Framework Core) to manipulate data to improve performance and user experience.

Technologies: JavaScript, Ajax, .NET Core, CSS, HTML, .NET 6, SlickGrid, CSS Grid, Entity Framework Core, Web Methods, LINQ

Technical Lead

2017 - 2022

MCB A/S

Worked as a technical supervisor for an offshore development team to ensure the quality of the code by doing peer reviews and applied unit and automation tests heavily.
Contributed as a system architect or technical advisor to research and propose the best technical solutions that meet customer-specific requirements and feature enhancement while still being able to ensure system integrity and conformity.
Built and led a high-performance team of senior developers to maintain and develop the eCommerce platform—the core product—with several versions developed in ASP Classic, ASP.NET Web Forms, ASP.NET MVC, React, .NET Core, Blazor, and more.
Utilized React as a drop-in solution into the existing ASP.NET MVC application to enhance user experiences, flexibility, application performance, and throughput.
Optimized front-end applications on both desktop and mobile devices using dynamic bundling and chunking system plus device-splitting solutions to minimize page loads as neatly as possible.
Built and delivered a new version of platform back-end CMS (content management system) using Blazor (.NET Core).
Applied and ran the development process smoothly using Agile, Scrum, and Kanban daily.

Technologies: GitHub, RESTful Web Services, Web Services, Sass, Windows PowerShell, VBScript, CSS, jQuery UI, Swagger, Visual Studio Code (VS Code), Scrum, Git, Redux, HTML5, Selenium, MVC Razor, Bootstrap 3, REST APIs, XML, SQL Server Management Studio (SSMS), Microsoft SQL Server, ASP.NET Web API, ASP.NET Web Forms, Agile, Visual Studio, SQL, .NET, C#, Windows, Docker Swarm, Docker, Microservices, TeamCity, Continuous Delivery (CD), Continuous Integration (CI), DI, LLBLGen, Entity Framework, Web API, .NET Core, ASP.NET MVC, Blazor, JavaScript, jQuery, Bootstrap, Node.js, Gulp, TypeScript, React, Angular, Kubernetes, Entity Framework Core, NUnit, Multithreading, APIs, RESTful Development, Subversion (SVN), REST, Ajax Control Toolkit, Classic ASP, Dependency Injection, Extreme Programming, Redux Thunk, Entity, JSON, HTML, Back-end Development, Back-end, C#.NET, Web Development, Razor, Software Consulting, Software Consultant, T-SQL (Transact-SQL), Active Server Pages (ASP), Single Sign-on (SSO), OAuth, OAuth 2, SAML, Architecture, SAML-auth, Identity Server, OpenID, Azure, ASP.NET Core, Plugins, Full-stack, JSON Web Tokens (JWT), Web App Development, Integration, Software Architecture, Code Review, Source Code Review, CI/CD Pipelines, Project Consultancy, Design Patterns, Mobile Development, Technical Leadership, Microsoft, Minimum Viable Product (MVP), UI Components, IIS, Dapper

Offshore Development Lead

2012 - 2019

ChangeDriver

Led a team of three offshore developers to maintain and develop more advanced features for a product that allows large organizations to control and publish their blueprints.
Maintained and enhanced ActiveX control for embedding Microsoft Office applications into a web-based organization-blueprint editor tool using COM+, DCOM, ActiveX, and JavaScript.
Set up a CI/CD system using ThoughtWorks GO and MSBuild scripts to automate the build and deployment of the product. Developed SharePoint web parts to help show organization blueprint publications inside SharePoint, used as their ERP system.
Developed a new version of a web-based publication wiki application where organization employees could sign in to see information and instructions about the processes, activities, regulations, and compliance they need to follow and perform.
Implemented the SSO (single sign-on) function, which can be federated with the clients' organization corporate network seamlessly using Active Directory Federation Services (AD FS) and WIF.
Integrated and built an extended identity provider service to allow sign-in with Google, Facebook, and LinkedIn using C#, WIF, and OpenAuth1/2.
Constructed an on-demand infrastructure with AWS CLI and C# that would automatically scale up or down to serve multiple heavy operations simultaneously.
Created an automated backup and restore system to improve product availability and fault tolerance. Built a centralized claim-based authentication and authorization system for the product using AD FS, C#, SAML1.1/2, WIF, and WCF.
Incorporated WiX, XAML, and C# to build an installer of the whole product for customers who want to run their private version within their corporate network.
Created and developed a remote logging system to synchronize logs from private installations of the product with a cloud-based logging system for more accessible support and diagnostics. Applied Agile and Scrum using Jira and Microsoft Excel.

Technologies: RESTful Web Services, Visual Basic for Applications (VBA), MySQL, Amazon EC2, Amazon EC2 API, VBScript, OpenXML, jQuery UI, Git, HTML5, C, Continuous Delivery (CD), ADFS, MVC Razor, VB, Bootstrap 3, Visual Basic .NET (VB.NET), Telerik, REST APIs, C++, SQL Server Management Studio (SSMS), Microsoft 365, Microsoft SQL Server, ASP.NET Web API, ASP.NET MVC, ASP.NET Web Forms, Agile, XML, Visual Studio, SQL, .NET, C#, Windows, Windows PowerShell, Batch, SAML, Active Directory Federation, StringTemplate, Selenium, Microsoft Excel, DCOM, ActiveX, CSS, HTML, JSON, SharePoint, WIF, Web Services, JavaScript, jQuery, Ajax, ASP.NET, NUnit, Multithreading, Microsoft Office Interop, APIs, RESTful Development, Subversion (SVN), Continuous Integration (CI), MSBuild, Bash Script, REST, Ajax Control Toolkit, Dependency Injection, Extreme Programming, Wix Installer, Entity, Entity Framework, DI, Back-end Development, Amazon Web Services (AWS), Single Sign-on (SSO), Back-end, C#.NET, Web Development, Razor, Software Consulting, Software Consultant, T-SQL (Transact-SQL), Visual Basic 6 (VB6), OAuth, OAuth 2, Architecture, SAML-auth, Identity Server, OpenID, Plugins, Full-stack, JSON Web Tokens (JWT), Web App Development, Integration, Software Architecture, Code Review, Source Code Review, CI/CD Pipelines, Project Consultancy, Visual Basic, Design Patterns, Mobile Development, Technical Leadership, Microsoft, Minimum Viable Product (MVP), IIS, Dapper, Windows Communication Foundation (WCF)

Project Lead

2010 - 2012

DTT Globeteam Incorporation

Led the team of around eight developers to build a product that helps large organizations to document, maintain, and publish their blueprints.
Coordinated with clients for ideas and feedback to improve the product.
Re-architectured and designed product based using Visio, UML, and Rational Rose.
Developed an ActiveX control for embedding Microsoft Visio, Word, and Excel into a browser to allow users to work with the product seamlessly using C++, JavaScript, and COM+/DCOM/ActiveX.
Ensured that ActiveX control is aligned and could run smoothly in various security scenarios within corporate networks.
Developed web-based editor tools using ASP.NET WebForms, AJAX, jQuery, JavaScript, HTML/CSS, Web services, and XML/JSON for users to edit the content of their organization's blueprints such as diagrams, documents, instructions, and publications.
Developed a publishing system including a web-based application and publishing services to allow organizations to create an official publication of their blueprints.
Created ClickOnce installation for WinForm application using Visual Studio.
Used JIRA/MS Excel to apply Agile/Scrum into the development process.

Technologies: Visual Basic for Applications (VBA), MySQL, jQuery UI, C, Continuous Delivery (CD), ADFS, Selenium, MVC Razor, VB, Bootstrap 3, Visual Basic .NET (VB.NET), REST APIs, JavaScript, SQL Server Management Studio (SSMS), Microsoft 365, Microsoft SQL Server, ASP.NET Web Forms, Agile, XML, Visual Studio, SQL, .NET, C#, Windows, Telerik, CSS, HTML, Microsoft Excel, DCOM, ActiveX, C++, ClickOnce, WIF, RESTful Web Services, Web Services, jQuery, JSON, Ajax, ASP.NET, VB.NET, Multithreading, APIs, Continuous Integration (CI), MSBuild, Extreme Programming, Back-end Development, Amazon Web Services (AWS), Single Sign-on (SSO), Back-end, REST, C#.NET, Web Development, Razor, Software Consulting, Software Consultant, T-SQL (Transact-SQL), Visual Basic 6 (VB6), OAuth, Architecture, Full-stack, JSON Web Tokens (JWT), Web App Development, Integration, Software Architecture, Code Review, Source Code Review, CI/CD Pipelines, Project Consultancy, Visual Basic, Design Patterns, Technical Leadership, Microsoft, Minimum Viable Product (MVP), IIS, Dapper, Windows Communication Foundation (WCF)

Development Lead

2007 - 2009

DTT Globeteam Incorporation

Worked closely with the project manager, QA lead, and customers to evaluate requirements; provide technical solutions; define SRS (software requirement specifications); and define scopes, milestones, and high-level iteration plans using MS Project and Microsoft Word/Excel.
Coordinated with all team leads to work out detailed implementation plans for each and every iteration using MS Project and Excel.
Set up and built a CI (continuous integration) system using TFS (Team Foundation Server) and Cruise Control.
Built and developed core business services with ESB (Enterprise Service Bus) using C#, WCF (Windows Communication Foundation), XML, and SOAP.
Built and set up a unit testing system to integrate into CI in order to ensure quality. Trained and embraced developers to create unit tests which eventually reached 55% code-coverage.
Supported front end team to built up web-based applications using ASP.NET Web-forms, JavaScript, WCF, SOAP, and AJAX.
Participated in recruiting and training new developers for project needs.
Joined scrum review sessions every week with the project manager and customer to update them with status, progress and issues.
Set up a network load-balancing system to improve the availability and performance of web-based applications that could serve thousands of concurrent users.

Technologies: Continuous Delivery (CD), REST APIs, SQL Server Management Studio (SSMS), Microsoft SQL Server, XML, Visual Studio, SQL, .NET, C#, Windows, Infragistics, Oracle Service Bus (OSB), Object-oriented Programming (OOP), Service-oriented Architecture (SOA), JavaScript, Microsoft Project, CruiseControl, TFS, Ajax, ASP.NET, Windows Presentation Foundation (WPF), Web Services, Multithreading, APIs, Continuous Integration (CI), MSBuild, Extreme Programming, JSON, Back-end Development, Back-end, REST, C#.NET, Web Development, Razor, Software Consulting, Software Consultant, T-SQL (Transact-SQL), Visual Basic 6 (VB6), Architecture, Full-stack, Web App Development, Integration, Software Architecture, Code Review, Source Code Review, Project Consultancy, Visual Basic, Design Patterns, Technical Leadership, Microsoft, IIS, Dapper, Windows Communication Foundation (WCF)

Team Lead

2007 - 2007

DTT Globeteam Incorporation

Developed a rich and smart desktop-base PIM (Product Information Management) client application using C#, WinForms, Infragistics library, WCF (Windows Communication Foundation).
Participated in designing an SOA (Service-oriented Architecture) for the whole system.
Used WCF to build an ESB (Enterprise Service Bus) to serve as a generic message-based communication channel for all services and applications.
Designed and built a dynamic form-based application using C# and XML which can easily be extended and modified to meet UI and UX requirements without having to change the codes.
Widely applied asynchronous communications between end applications and services to give users the best experiences.
Led a small team of six developers to work mostly on end applications.
Coordinated with the services and databases team to ensure development priorities and planned are aligned together efficiently.
Worked together with the QA team and customers to evaluate requirements, to review and continuously improve the application.

Technologies: Continuous Delivery (CD), SQL Server Management Studio (SSMS), Microsoft SQL Server, XML, Visual Studio, SQL, .NET, C#, Windows, Infragistics, Oracle Service Bus (OSB), Object-oriented Programming (OOP), Service-oriented Architecture (SOA), JavaScript, Microsoft Project, CruiseControl, TFS, Ajax, ASP.NET, Windows Presentation Foundation (WPF), Web Services, Multithreading, APIs, MSBuild, Classic ASP, Visual SourceSafe, Extreme Programming, JSON, Back-end Development, Back-end, C#.NET, Web Development, T-SQL (Transact-SQL), Integration, Software Architecture, Code Review, Source Code Review, Visual Basic, Design Patterns, Technical Leadership, Microsoft, IIS, Windows Communication Foundation (WCF)

Teaching Assistant

2004 - 2006

Faculty of Technologies, National University of Hanoi

Developed and created a digital library for the faculty using Greenstone open-source software.
Assisted in giving lectures to students in various areas of computer and information systems.
Trained and supported students to work on a lot of small projects using C#, C/C++, VB, VB.NET, SQL, and ASM.
Set up and worked on different internship projects with several government departments using Microsoft Access + VBA, PHP, MySQL, and .NET-based WinForms.

Technologies: Assembly, Visual Basic .NET (VB.NET), Microsoft SQL Server, Visual Studio, SQL, C#, Windows, MySQL, PHP, Pascal, VB, C++, C, HTML, Back-end Development, Back-end, C#.NET, T-SQL (Transact-SQL), Visual Basic 6 (VB6), Active Server Pages (ASP), Visual Basic, Microsoft

Intern Developer

2003 - 2004

Data Technology Co. Ltd.

Created production-level codes using both C++ and C# to build a unified communication system.
Applied Agile methodologies to build a professional software development process that acted fast on changes and reduced time to live.
Widely used and applied OOP/OOAD, design patterns/SOLID, and best practices.
Built an interactive voice response system based on XML and VXML.

Technologies: C, XML, Visual Studio, SQL, .NET, C#, Windows, Remoting, VXML, C++, Visual SourceSafe, Extreme Programming, HTML, Back-end Development, Back-end, C#.NET, T-SQL (Transact-SQL), Visual Basic

Experience

MCB A/S

Almost right after joining MCB, as the lead developer, within 9 months I have successfully built a new version of our eCommerce platform using ASP.NET MVC and React as a drop-in solution. The new version is so flexible, stable and faster that almost 80% of our existing customers have decided to upgrade to new version. Besides, we have also succeeded in selling for 5 more big B2B customers.

By adding more unit/automation tests, pair reviewing/programming refactoring and mentoring to build high-quality code, we have reduced support hours by 50% not only on the new versions but also on old versions of our e-commerce platform.

We have been tuning performance using RedGate ANTS profiling tools, using DI (Dependency Injection), caching, dynamic bundling, lazy loading, asynchronous loading to help increasing throughputs up to 45% and optimizing page loads by more than 60% to be around < 1s in average on all online shops.

ChangeDriver A/S

Leading a team of 3 core and senior developers, I built a completely new version of ChangeDriver from scratch to bring it from a Desktop-based application to a cloud-based SaaS (Software as a Service) running on AWS.

I made it possible to embed Microsoft Office Applications such as Visio, Word, and Excel using C++/COM+/ActiveX to allow process owners to use ChangeDriver Editor as a unified tool/application for building their organization blueprints.

Based on WIF (Windows Identify Foundation) and with AD FS (Active Directory Federation Services), I was able to add SSO (Single-Sign-On) to ChangeDriver multi-tenancy system supporting federation with customer corporate networks, LinkedIn, Google, SharePoint.

Using ChangeDriver, organizations usually publish their blueprints for their employees to understand their processes and execute them accordingly. In order for being able to handle multiple large publications concurrently, I developed an auto scale-out publishing system with AWS EC2 CLI, WCF, .NET 4.0 multi-threading techniques.

I also created several powerful RESTful APIs to serve the data to not only present publications to organization employees but also to allow integration with organizations' ERP systems.

Vacasol A/S

Within 3 and a half years, as offshore development lead most of the time, I was able to reach 90% of milestones throughout the project.

By using WCF (Windows Communication Foundation), SOAP/XML, self-made ESB (Enterprise Service Bus), we did build up a very flexible, highly scalable SOA (Service-oriented Architecture) system that helped property owners to easily enter vacation houses; contract partners to define flexible and multi-level pricing systems; end-users to search and book vacation houses through our load-balanced web applications; and reseller partners to do bi-directional synchronization with Vacasol databases.

For the last 1 year within the project, I did tune the performance a lot to allow loading property detail page and searching thousands of houses in less than 3 seconds.

Skills

Languages

C#, SQL, XML, C#.NET, T-SQL (Transact-SQL), Visual Basic, SAML, C++, Visual Basic .NET (VB.NET), TypeScript, JavaScript, HTML, CSS, HTML5, VB, C, Bash Script, Visual Basic 6 (VB6), Active Server Pages (ASP), Pascal, PHP, VB.NET, Batch, VBScript, Assembly, Visual Basic for Applications (VBA), Sass

Frameworks

.NET, ASP.NET, ASP.NET MVC, ASP.NET Web API, NUnit, ASP.NET Web Forms, Razor, Bootstrap, Classic ASP, .NET Core, MVC Razor, WIF, Blazor, Bootstrap 3, Entity, ActiveX, Redux, Swagger, Selenium, OAuth 2, ASP.NET Core, JSON Web Tokens (JWT), Windows Presentation Foundation (WPF), Angular, Windows PowerShell, Entity Framework Core, .NET 5

Libraries/APIs

jQuery, REST APIs, Node.js, Web API, Entity Framework, React, Ajax Control Toolkit, Azure Blob Storage API, OpenID, jQuery UI, Amazon EC2 API, Infragistics, SlickGrid, LINQ, Vue

Tools

Visual Studio, GitHub, LLBLGen, MSBuild, ADFS, TFS, Visual SourceSafe, Git, Redux Thunk, Subversion (SVN), xUnit, Wix Installer, Microsoft Office Interop, Dapper, FxCop, Microsoft Project, Microsoft Excel, StringTemplate, Gulp, TeamCity, Docker Swarm, Figma, Bitbucket

Paradigms

Agile, REST, Design Patterns, RESTful Development, Scrum, Extreme Programming, Continuous Integration (CI), Continuous Delivery (CD), Dependency Injection, Mobile Development, Service-oriented Architecture (SOA), Object-oriented Programming (OOP), Microservices, COM+

Platforms

Windows, Visual Studio Code (VS Code), Telerik, Microsoft, SharePoint, Docker, Amazon EC2, Kubernetes, Amazon Web Services (AWS), Azure

Other

Ajax, Back-end Development, Back-end, Web Development, Web App Development, Code Review, Source Code Review, Project Consultancy, Technical Leadership, Front-end Development, Windows Communication Foundation (WCF), Static Analysis, Web Services, RESTful Web Services, Microsoft 365, APIs, Multithreading, DI, Single Sign-on (SSO), Software Consulting, Software Consultant, OAuth, Architecture, SAML-auth, Identity Server, Full-stack, Integration, Software Architecture, CI/CD Pipelines, Minimum Viable Product (MVP), UI Components, IIS, Remoting, CruiseControl, Oracle Service Bus (OSB), ClickOnce, DCOM, Active Directory Federation, VXML, Plugins, DevExpress, .NET 6, CSS Grid, Web Methods, Containerization, Azure Service Bus, Azure Container Instances

Storage

JSON, Microsoft SQL Server, SQL Server Management Studio (SSMS), OpenXML, MySQL, Amazon S3 (AWS S3), Azure Cosmos DB, MongoDB

Education

2000 - 2004

Bachelor's Degree in Computing and Information System, Software Technologies

Faculty of Technologies, National University of Hanoi - Hanoi, Vietnam

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