My name is Jeff Handley. I’ve been creating web applications for over 20 years. I grew up on the Microsoft stack but now I focus on Node, React, Redux, and GraphQL. I have passion for implementing large web applications that provide end-user productivity and delight.

The teams I’ve worked with have a proven ability to deliver short-term developer productivity and long-term maintainability for web applications ranging from 10 screens to over 1000. I’ve been recognized as a compassionate people manager with an unparalleled sense of ownership in products and user experiences. These traits have helped me lead many teams through successful releases.

I’ve had the pleasure of speaking at several conferences including Øredev, MonkeySpace, OuterConf, and Silicon Valley Code Camp. I am the author of the DataAnnotations validation features built into the .NET framework, the Strickland JavaScript validation framework, and a few other npm packages.

SAP Concur

I’m the Senior Director of Web UI Engineering at SAP Concur. I work with the teams that deliver our core UI components, our UI infrastructure, our corporate travel booking experience, our expense experience, and the setup experience for our SMB expense and invoice products.

Our group includes teams in Bellevue, WA, USA and Prague, Czech Republic. We also have team members who work from home across several states and time zones. We partner with teams in California; Texas; Virginia; Maidenhead, UK; Prague; and Frankfurt, Germany.


Many folks know of me from my time at Microsoft. I was the Engineering Manager for the NuGet Package manager, WCF RIA Services, ASP.NET Web Pages, Razor, and a few other projects. I helped open-source the Silverlight SDK and RIA Services. I led NuGet from being a small open-source project to shipping as part of Visual Studio, building a team around it along the way.

While at Microsoft, I was the lead developer of the validation validation features built into the .NET Framework’s System.ComponentModel.DataAnnotations namespace. My work included IValidatableObject, ValidationResult, ValidationContext, and Validator, among other implementation details introduced in .NET 4.0. Those features delivered validation functionality into ASP.NET MVC, ASP.NET Web Forms, WCF RIA Services, Silverlight, and WPF.

Early Career

My first professional programming experience was at a small civil engineering firm in Milford, OH. When tasked with performing complex math calculations for projects, I decided to automate the calculations with a QuickBasic application that saved the company time on many projects.

I then joined SDRC (now Siemens) at the age of 17. There, I worked in the quality certification group where I conducted manual testing, helped the group automate large portions of our test suite, and built intranet applications for managing the test suites and results. I also created the company’s HR website including an online job application form where I used JavaScript for the first time. Back then, only form controls could be manipulated.

After SDRC, I spent over 10 years building business systems for companies of all sizes. I cofounded (now Website Physician) where we built web applications for medical offices and fertility clinics, various small businesses, a point-of-sale system for Proctor and Gamble, a mortgage processing system used by many large lenders, and over 200 clients overall.

I also worked at a consulting company where I architected the student information system used by 680 public school districts across the state of Ohio. I architected and led development of a healthcare waste management solution and I helped build a popular fantasy football web application used by over 30,000 league members.