Siem Vaessen
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Siem Vaessen Email & Phone Number

CEO | ZIMMERMAN B.V. at Zimmerman
Location: Amsterdam, North Holland, Netherlands 33 work roles
1 work email found @zimmerman.team 2 phones found area 120 LinkedIn matched
✓ Verified Jun 2026 4 data sources Profile completeness 86%

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Current company
Role
CEO | ZIMMERMAN B.V.
Location
Amsterdam, North Holland, Netherlands

Who is Siem Vaessen? Overview

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Siem Vaessen is listed as CEO | ZIMMERMAN B.V. at Zimmerman, based in Amsterdam, North Holland, Netherlands. AeroLeads shows a work email signal at zimmerman.team, phone signal with area code 120, and a matched LinkedIn profile for Siem Vaessen.

Siem Vaessen previously worked as IATI Governing Technical Board Member at International Aid Transparency Initiative and Data Management Specialist | FCDO at Zimmerman B.V..

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Profile bio

About Siem Vaessen

Siem is a data visualisation expert and a passionate advocate for open data and machine learning in the international aid development sector. He has over 25 years of experience working with global organisations to provide data products and services that help them understand their data life cycle and the impact of their work.As the CEO of Zimmerman B.V., he leads the agile design and development team that creates innovative and user-friendly data visualisation portals for clients such as FCDO and The Global Fund. He also contributes to raising awareness of open data and data quality standards through the IATI.Cloud platform, which enables data sharing and analysis across the sector. Siem's mission is to enable effective aid development through the lens of data, and to empower organisations to make data-driven decisions.

Listed skills include Strategy, Web Design, Multimedia, Project Management, and 9 others.

Current workplace

Siem Vaessen's current company

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Zimmerman
Zimmerman
CEO | ZIMMERMAN B.V.
Amsterdam, NH, NL
AeroLeads page
33 roles

Siem Vaessen work experience

A career timeline built from the work history available for this profile.

Ceo | Zimmerman B.V.

Amsterdam, NH, NL

Iati Governing Technical Board Member

Current

The IATI Governing Board takes a leadership role in overseeing the implementation of IATI’s work. The board puts recommendations on key budget and strategic issues to the Members’ Assembly for final approval.The Board is made up of seven members representing providers of development cooperation, partner countries and civil society, non-governmental and.

Apr 2024 - Present

Ceo | Zimmerman B.V.

Current

Amsterdam Area, Netherlands

We contribute to a better understanding for effective aid development through the lens of open data and data visualisation. Over the past decade we have been serving global organisations operating in the field of humanitarian assistance to provide data products and services and raise awareness of open data making use of machine learning and data.

Jan 2011 - Present

Data Management Specialist | Fcdo

Current

Amsterdam Area

Foreign, Commonwealth & Development Office (FCDO )is a United Kingdom government department responsible for administering overseas aid. The goal of the department is "to promote sustainable development and eliminate world poverty". DFID is headed by the United Kingdom's Secretary of State for International Development.

Jan 2012 - Present

Product Development Manager | The Global Fund

Current

Geneva, Switzerland

The Global Fund aims to accelerate the end of AIDS, tuberculosis and malaria as epidemics. As an international organization funded by the European Union, the US, China, Japan and several philanthropic organizations, The Global Fund mobilizes and invests more than $ 4 billion annually to support programs in more than 100 countries.In order to gain a better.

Jan 2018 - Present

Information Technology Management | Unesco

Amsterdam Area

UNESCO is the educational, scientific and cultural organization of the United Nations. Siem, together with the digital innovation team of UNESCO in Paris, went through various parts of the Design Thinking method. In the first phase, they jointly established the strategic framework and mapped out the technical requirements. Subsequently, he initiated a user.

Jun 2015 - May 2022

Information Technology Specialist | Odi

Amsterdam Area

ODI is an independent, global think tank based in London. Their vision is a sustainable and peaceful world in which everyone thrives. They use the power of evidence and ideas through research and partnership to face challenges, develop solutions and create change.Siem worked with a scrum team from ODI on a completely new open IATI Transparency Portal. Siem.

Jan 2014 - May 2022

Product Delivery Manager | Iati

Amsterdam Area

IATI is a global initiative to improve the transparency of development and humanitarian resources and their results for addressing poverty and crises.IATI brings together governments, multilateral institutions, private sector and civil society organisations and others to increase the transparency of resources flowing into developing countries.

Oct 2018 - Jul 2021

Data Manager | Development Initiatives

Amsterdam Area

The IATI Humanitarian Data Portal has been developed by Development Initiatives as part of its programme to support the Grand Bargain transparency workstream. The portal provides information on the Grand Bargain transparency commitments, how they are measured, and monitors progress at an aggregate level for signatories in meeting their commitment to.

Jan 2019 - Jan 2021

Data Management Team Lead | Aidsfonds

Amsterdam Area

Aidsfonds is available for everyone in the Netherlands and abroad who is dealing with HIV / AIDS. Aidsfonds finances scientific research, stands up for the rights of people with HIV and develops and finances projects for prevention and treatment for vulnerable groups.Together with a project team from the Aidsfonds, Siem designed the Zoom data platform.

Jun 2015 - Dec 2020

Product Manager | International Organisation For Migration

Amsterdam Area

With 173 Member States and offices in more than 100 countries, IOM is committed to promoting humane and orderly migration. It does this by providing services and advice to governments and migrants. IOM is committed to orderly and humane migration management, to promoting international cooperation on migration issues, to seeking practical solutions to.

Jun 2017 - Jul 2020

Product Delivery Manager | Municipality Of Almere

Amsterdam Area

In 40 years, Almere has grown into the 8th city of the Netherlands with more than 200,000 inhabitants. Together with the registry of Almere and Leiden University, SIem worked as a senior UX advisor on the Open Council Information web platform. The primary goal was to make decision making more transparent for councilors and residents of Almere.Siem's.

Jan 2018 - Jan 2020

Project Delivery Manager | Netherlands Enterprise Agency

Amsterdam Area

The national government is committed to an excellent business climate. Ministries set out policies for this. The task of implementing this policy lies with the Netherlands Enterprise Agency (RVO).The user tests consisted of a think aloud procedure and an open question interview that were conducted on location. Based on the results, he gave advice on.

Jan 2016 - Jan 2020

Product Development Manager | Un-Habitat

Amsterdam Area

UN-Habitat headquartered in Nairobi (Kenya) is working for a brighter future for all cities in the world. UN-Habitat is located in more than 90 countries and promotes the development of socially and environmentally sustainable cities, towns and communities. UN-Habitat strives for sufficient shelter with a better standard of living for everyone.Siem.

Jan 2013 - Sep 2018

Product Manager | Iati Studio

Amsterdam Area

IATI Studio was an interactive Data Toolkit that made it possible to visualise, analyse and publish aid development data published to the IATI Standard. IATI Studio extracted all IATI datasets covering $150 billion of aid published in the IATI format, and provided access to easy online tools to interact with all of that aid data. It promoted accountability.

Jan 2016 - Jan 2018

Data Specialist | Interaction

Amsterdam Area

Founded in 1984, InterAction is the largest alliance of international NGOs and partners in the United States. They mobilize members to think and act together to help the world's poor and vulnerable.

Oct 2016 - Oct 2017

Ceo | Open Data Company B.V.

Current

Amsterdam, North Holland, Netherlands

The Open Data Company aims to create a transparent world where people and organisations are empowered to use data to drive change for a better future by unlocking the full potential of aid development data in order for them to drive change in today's complex & interconnected world.

Jun 2021 - Present

Project Manager | Oxfam Novib

Amsterdam Area

Oxfam Novib tackles the problems that cause and perpetuate poverty: hunger, insecurity, injustice and lack of perspective. Together with local partners, they offer people the means and knowledge to stand on their own two feet.Siem has designed the information architecture, the UX and visual design of the new dashboard in various ways and tested this.

Jan 2015 - Jan 2016

Data Specialist | Leiden University

Amsterdam Area

At the Center for Innovation / HumanityX in The Hague, part of Leiden University, they focus on people and context. They develop learning experiences, applications, technologies and methodologies, always focused on understanding, exploring and influencing basic problems.The challenge was to develop a UX concept together with a research team from Leiden.

Jan 2015 - Oct 2015

Product Delivery Manager | Ministry Of Foreign Affairs The Netherlands

Amsterdam Area

The national government is committed to an excellent business climate. Ministries set out policies for this. The task of implementing this policy lies with the Netherlands Enterprise Agency (RVO).Siem has been involved in the first Netherlands Enterprise Agency open IATI Data Portal that was developed on behalf of The Netherlands Enterprise Agency. The web.

Jan 2011 - Jan 2015

Project Manager | Rain Foundation

Amsterdam Area

Sufficient and safe water must be available to everyone. Unfortunately, many people do not have access to safe water. How do you change that? Harvest rainwater! Since its establishment in 2003, RAIN has been working with its partners to develop, distribute and implement rainwater collection systems.

Jan 2012 - Jan 2013

Digital Consultant

Hilversum, The Netherlands

Sound and Vision is the institute for media culture; an inspiring, creative and accessible meeting place for private individuals and professionals. We interpret current developments concerning people, media and society from a media-historical perspective.As part of the project ‘Images for the Future’ Siem was requested to create specifications for a.

Sep 2009 - Nov 2014

Project Manager

The Hague Area, Netherlands

Akvo believes in equal access to public services, reliable infrastructure and a safer environment for everyone. They are convinced that this will happen faster if governments and non-governmental organisations become more effective, accountable and collaborative.Akvo’s combination of tools, services, local expertise and sector knowledge, Akvo’s partners.

Dec 2009 - Apr 2010

Consultant

Aspo Netherlands

Wrote specifications for an oil benchmarking tool for SME's in the Netherlands.

Sep 2009 - Apr 2010

Governing Board Member

Aspo Netherlands

Finding awareness opportunities for the foundation and laying out the financial structure.

Jun 2005 - Sep 2009

Marketing Director

Branding development, advertising solutions, product sales.

Oct 2007 - Jun 2009

Coo

Maintained a healthy balance between project scope, delivery and products.

Jun 2005 - Aug 2007

Project Manager

Lead a variety of complex ICT integration projects involving different (third) parties, controlling and monitoring set milestones and deliverables.

Oct 2004 - May 2005

Director | Webcode

Webcode

Amsterdam Area, Netherlands

Webcode was an internet agency based in Amsterdam with a key focus on providing internet solutions to clients in the field of cultural heritage.

Sep 1999 - Jul 2005

Board Member

Stork'S Nest

Localising affordable artists workspaces in Amsterdam and creating a sustainable businessplan for artists to run their own workspaces.

May 2002 - Apr 2005

Freelance Photojournalist

Pakistan

Getty Images is among the world’s leading creators and distributors of award-winning still imagery, video, music and multimedia products, as well as other forms of premium digital content, available through its trusted house of brands, including iStock© and Thinkstock©.Siem covered the conflict in Kashmir (1999).

Apr 1999 - Jun 1999

General Manager

Amsterdam, North Holland, Netherlands

Day to day production management of photo-reportages. Editing, sales.

Jun 1997 - Jun 1998

Senior Photo Editor | Abc Press

Amsterdam Area

ABC Press was an international photo agency in Amsterdam that represented international renowned photographers and photo collectives like Magnum Photography.Archiving and editing. Creating pre-selections of images for client-portfolio, mainly dutch magazines and newspapers.

May 1993 - May 1997
FAQ

Frequently asked questions about Siem Vaessen

Quick answers generated from the profile data available on this page.

What company does Siem Vaessen work for?

Siem Vaessen works for Zimmerman.

What is Siem Vaessen's role at Zimmerman?

Siem Vaessen is listed as CEO | ZIMMERMAN B.V. at Zimmerman.

What is Siem Vaessen's email address?

AeroLeads has found 1 work email signal at @zimmerman.team for Siem Vaessen at Zimmerman.

What is Siem Vaessen's phone number?

AeroLeads has found 2 phone signal(s) with area code 120 for Siem Vaessen at Zimmerman.

Where is Siem Vaessen based?

Siem Vaessen is based in Amsterdam, North Holland, Netherlands while working with Zimmerman.

What companies has Siem Vaessen worked for?

Siem Vaessen has worked for Zimmerman, International Aid Transparency Initiative, Zimmerman B.V., The Open Data Company, and Sound And Vision.

How can I contact Siem Vaessen?

You can use AeroLeads to view verified contact signals for Siem Vaessen at Zimmerman, including work email, phone, and LinkedIn data when available.

What skills is Siem Vaessen known for?

Siem Vaessen is listed with skills including Strategy, Web Design, Multimedia, Project Management, Research, Software Development, Marketing, and Business Strategy.

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