Developer/Programmer HAS

Project overview

PLEASE NOTE: This assignment is not available for direct freelance deployment. Deployment is only possible through a secondment agency/supplier or via a payroll/employment contract. The work will be carried out under the direction and supervision of a public executive organization, therefore independent deployment is not permitted. Offering suppliers must be able to be included in the chain. For this, WAADI registration and a G-account are required.

Candidates who wish to participate as independent entrepreneurs can only be proposed when they are deployed through an authorized secondment agency or employment contract.

You are the developer/programmer of our HAS system. HAS stands for Handhaving Administratie Systeem (Enforcement Administration System) and is the administration system for Supervision and Enforcement of the municipality of Rotterdam, cluster City Management.

Your role

The enforcers of T&H use various systems to register violations in the public space of the municipality of Rotterdam. These include handheld applications such as iThor and (partially) automated systems. The input of these violations via mobile phone is processed in HAS in real-time for further processing. From HAS, further handling of these matters is facilitated.

We are looking for someone who can maintain these systems at a source code level, analyze and resolve malfunctions, and develop improvements and new functionalities. Knowledge at source code level is necessary for this.

You will work on maintaining, adapting, and improving existing functionalities and contribute to the further development of the applications. You will work on both the backend and the frontend of web applications.

You develop and maintain applications with C# and the .NET framework and work with MS SQL Server for storing, managing, and accessing data. For the frontend, HTML, CSS, and JavaScript are used.

In addition, you work with web services and API connections, including SOAP.

Besides developing new functionalities, you will be involved in maintaining and supporting existing applications. You analyze and fix bugs and malfunctions and ensure that changes are implemented carefully.

You collaborate with colleagues within an agile working environment and use version control systems such as Git.

Because the systems are used within the municipal enforcement chain, it is important that you handle data carefully and take into account the applicable privacy legislation, including the GDPR.

Requirements

We are looking for a Programmer/Developer/full stack.

You are, first and foremost, a developer/programmer at heart, who is also capable of translating business needs into the application. You have good communication skills to effectively collaborate with various stakeholders. Additionally, you have the ability to analyze and solve complex problems.

You are flexibly deployable based on the hours per week.

Wishes

The Supervision and Enforcement department is involved in various supervisory and enforcement tasks such as control of: Buildings with Urban and Area-Specific Intervention Teams, Markets, Youth, Bikers, Alcohol & Hospitality, Taxi, and Environmental Enforcement. In addition, enforcement is carried out on, among other things, parked cars, car wrecks, bicycles, waste on the street, illegal posters, and depositing waste in underground containers.

The Functional Management department is responsible for the management of the applications that the supervisors use in the field.

Our organization

The living environment is important for the quality of living, working, and staying in Rotterdam. The City Management cluster of the Municipality of Rotterdam shapes the city, both underground and above ground. The fields of Public Works, Clean City, and Supervision & Enforcement work together to achieve this. We know the districts of Rotterdam, are aware of what is happening, and who lives and works there. The needs of citizens, businesses, and clients are central to this. Of course, we also value craftsmanship highly.

City Management is an organization where people are proud of their work and collaborate to improve the results on the street. They roll up their sleeves every day for a well-maintained Rotterdam. Because it can always visibly be better.

• You have at least a completed HBO (higher professional education) degree;
• You have at least 5 years of work experience as a developer, gained in the last 7 years;
• You have work experience gained at a municipality with at least 160,000 inhabitants;
• You have knowledge of and work experience with the General Data Protection Regulation (GDPR) and the GDPR Implementation Act (UAVG);
• You have experience with development methods such as: C# and JavaScript;
• You have at least 5 years of work experience with MS SQL;
• You have at least 5 years of work experience as a .NET developer;
• You have experience with building web applications with C# and ASP.NET;
• You have knowledge of HTML, CSS, and JavaScript.
• You have work experience with VB programming;
• You have work experience with SOAP;
• You have work experience with SQL Server database development;
• You have work experience with Object Oriented Programming;
• You have work experience with iOS development;
• You have experience with developing and integrating SOAP APIs;
• You have experience with maintaining and supporting existing applications, including resolving bugs and implementing new functionalities;
• You have experience with working in agile teams and using version control systems such as Git.

Project details

• Start: 2026-11-01T23:00:00
• Location: Rotterdam Zuid-Holland, NL
• Languages: Dutch