Jeffrey Voorhaar Email & Phone Number

Amsterdam, North Holland, Netherlands

Nextens is the market leader for fiscal software in the Netherlands and is part of the global RELX group.I have worked on many different projects during this hiring period.2024/2025: working on a RAG system using Azure OpenAI to provide a natural language interface to customers for their fiscal questions.2024: architected and shipped two new Azure Functions that integrate with the European Central Bank and services of the European Union that serve as information and validation endpoints within the Nextens ecosystem.2023: architected and shipped two completely new fiscal products that weren´t part of the portfolio yet.2022/2023: architected and shipped a product suite that services a completely new market segment for corporate customers. Its architecture balances perfectly between using existing core components and requirements, while using future oriented technologies and a modern design language.2021/2022: shipped a future proof fiscal knowledge search solution from scratch using ElasticSearch which delivers a much higher search relevance to users than before, while allowing for data driven tuning and optimization through continuous relevance monitoring. Skills: .NET, Azure, Azure OpenAI, Docker, DevOps, Git, ElasticSearch, Angular

Amsterdam Area, Netherlands

Allshare builds a modern, distributed and secure trading platform that forms a key component of major investment banks (Van Lanschot, Insinger Gilissen).I played a lead role in developing a module to calculate the buying power of a portfolio in real time based on complex mathematical rules and optimizations. The module was built around event sourcing and an LMAX disruptor, to achieve maximum processing performance and a very high throughput.The ecosystem in which the module lived consisted of over 80 containerized services communicating through a servicebus.Skills: .NET 5, DevOps, Git, Docker, RabbitMQ, MassTransit, MediatR, NATS, ElasticSearch,event sourcing, LMAX disruptor

Amsterdam Area, Netherlands

Nextens is the market leader for fiscal software in the Netherlands and is part of the global RELX group.Most of the time I spent designing and developing various scalable Azure applications using the latest backend and frontend technologies (.NET Core / Angular). I was closely involved in the architecture behind those applications, both from a software and an infrastructure perspective.I did extensive research on DDD, microservices and Kubernetes in my spare time, trying to apply the knowledge in practice as much as possible in my daily work.I was also involved in more global technology strategy and closely worked with product owners for planning, to define roadmaps and to align business with technology.I set in motion a plan to gradually work towards a full CI/CD pipeline to slowly migrate away from a classic release schedule, while not affecting team productivity of the 7 development teams in the process.Skills: .NET Core, Azure, DevOps, Git, Angular

Breukelen

Reeleezee was the very first online bookkeeping software company in the Netherlands. My primary task was architecting a cross-platform MVVM framework using Xamarin and build their mobile point-of-sale Cashr.Skills: C#, .NET, Xamarin, SQL, Silverlight

Utrecht

I have worked on various projects as a consultant during my time here:Raad van StateI was a developer on the team that realized the rework of the central knowledge and information system Raster to adapt it to current standards. I contributed to both the architecture and development of various use cases.Ministerie van Economische ZakenI was asked to evaluate and redesign the current version of a European tender system into a more robust future proof version. I led the team to migrate the application from classic ASP to a more actual ASP.NET version.IntergraphI was part of the team that implemented the mapping of gas tubes used during urban and industrial project planning in a new GIS software solution.ING BankI had a developer/architect role in a team that designed and built a new lead registration system. I also coordinated the offshore development team in India.Akzo Nobel Car RefinishesI was a developer on the team that worked on an application that translated input values from a photospectrometer to a color formula for car paint, for a best match with the actual car color during damage repairs.Skills: C#, ASP.NET MVC, SCSF, LLBLGen, Oracle, SQL, Project management, offshore development

Purmerend

Archie Europe is a leading CRM provider in the Netherlands. I primarily worked on the CRM product line, improving and extending functionality. I worked on the team migrating the product suite to a SQL backend. I also encouraged the use of source control and bug-tracking tools which I later integrated to support the development processes.Skills: Delphi, C#, .NET, ASP.NET, SQL, Bugzilla, Subversion

Hoofddorp

My main project was a mobile gate registration and notification system at Schiphol Airport that served multiple PalmOS handheld devices held by security personnel to make sure the gate status matched inbound and outbound flights.Skills: Delphi, SQL, HTML, CSS, JavaScript, PalmOS

Amsterdam

I have worked on several parts of the application Regedoc; an application for end-to-end encrypted transmission of documents. It also irrefutably logged when the document was sent and received for non-repudiation purposes.As this was my first junior programming role, I was learning on the job but also studied at home a lot to learn and improve the skills required for the job.Skills: C, C++, MFC, SQL, XML, PKI

Nutshell Webdevelopment was the name of my own company that I founded at the age of 17 to carry out web development work for clients.Skills: HTML, CSS, JavaScript, PHP, SQL, XML

Ing., Computer Science

Discrete Mathematics