Computer Scientist for dynamical core development
Bonn, Germany

Job reference: VN23-11

Location: Bonn, Germany

Deadline for applications: 29/03/2023

Publication date: 15/02/2023

Salary and Grade: Grade A2 EUR 83,888 NET annual basic salary + other benefits

Contract type: STF-PL

Department: Research

Contract Duration: 30 months with the possibility of extension

Your role 

This position is an exciting opportunity to make significant contributions to the development of the FVM dynamical core for the IFS with the GT4Py domain-specific library.  GT4Py will enable the model to be portable to the latest hardware and to run efficiently on the largest supercomputing platforms in Europe at km-scale global resolution. GT4Py will also provide a productive domain scientist interface agnostic to hardware-specific optimisation.  

The position is funded by the European Commission under the e-infrastructure programme in the third edition of the Excellence in Simulation of Weather and Climate in Europe (ESiWACE3) Centre of Excellence (  

At ECMWF, the successful candidate will work on the extension, optimisation and maintenance of the open-source Python embedded GT4Py domain-specific library targeting computational patterns of local cell-based discretization such as finite volumes that are common in the latest generation numerical weather prediction and climate models. The successful candidate will also study the use of reduced numerical precision for parts of the FVM model, to reduce the computational cost of integrations. 

The position will be part of the Numerical Methods Team of the Earth-System Modelling Section with close links to the Performance & Portability Team of the IFS Section at ECMWF. The candidate will perform advanced software development in agile projects with a larger expert team at our external partner institution, the Swiss National Supercomputing Centre (CSCS), who are leading the overall GT4Py library development. The position will be based in Bonn, Germany and we anticipate occasional visits to CSCS in Zurich, Switzerland and the ECMWF Headquarter in Reading, UK.

About ECMWF 

ECMWF is the European Centre for Medium-Range Weather Forecasts. It is an intergovernmental organisation created in 1975 by a group of European nations and is today supported by 35 Member and Co-operating States, mostly in Europe. The Centre’s mission is to serve and support its Member and Co-operating States and the wider community by developing and providing world-leading global numerical weather prediction. ECMWF functions as a 24/7 research and operational centre with a focus on medium and long-range predictions and holds one of the largest meteorological archives in the world. The success of its activities relies primarily on the talent of its scientists, strong partnerships with its Member and Co-operating States and the international community, some of the most powerful supercomputers in the world, and the use of innovative technologies such as machine learning across its operations.

Over the years, ECMWF has also developed a strong partnership with the European Union, and for the past seven years has been an entrusted entity for the implementation and operation of the Climate and the Atmosphere Monitoring Services of the EU Copernicus Programme, as well as a contributor to the Copernicus Emergency Management Service. The collaboration does not stop there and includes other areas of work, including High Performance Computing and the development of digital tools that enable ECMWF to extend its provision of data and products covering weather, climate, air quality, fire and flood prediction and monitoring.

ECMWF is a multi-site organisation, with its headquarters based in Reading, UK, a brand-new data centre in Bologna, Italy, and a large presence in Bonn, Germany. 

For additional details, see

Your responsibilities 

  • Extend, optimise, and maintain the domain-specific library for FVM 
  • Contribute to agile software development project cycles with close collaborations to ECMWF’s partners at the Swiss National Supercomputing Centre (CSCS) 
  • Perform comprehensive model testing on various CPU and GPU based supercomputing platforms 
  • Perform tests on the use of reduced numerical precision within the FVM model to reduce computational cost of model integrations 
  • Contribute to regular progress reports to the European Commission 

What we’re looking for

  • Flexible with a can-do attitude to handle the diverse requirements of this role
  • Excellent attention to detail, procedures and supporting solutions
  • Excellent analytical and problem-solving skills with a proactive approach
  • Excellent interpersonal and communication (verbal and written) skills 
  • Excellent coordination, planning and organisational skills.
  • Dedication and enthusiasm to work in a team efficiently and complete diverse tasks in a timely manner
  • Ability to work collaboratively in an international environment with teams from diverse cultures and backgrounds. 

Education and experience

  • An advanced degree (EQF Level 6) or equivalent in a relevant discipline.
  • Proficiency in advanced Python and C++
  • Experience in High-Performing Computing
  • Experience to work as part of a large software development project

Knowledge and skills 

We are searching for candidates with expertise across the majority of the following:

  • Implementation of numerical algorithms for NWP models or related fields 
  • Parallel and distributed computing
  • Domain-specific languages
  • Performance engineering
  • GPU programming (CUDA or HIP)
  • C++ Template Metaprogramming
  • Version control, release management and continuous integration

Candidates must be able to work effectively in English and interviews will be conducted in English. A good knowledge of one of the Centre’s other working languages (French or German) would be an advantage.

Other information 

Grade remuneration:  The successful candidates will be recruited at the A2 grade, according to the scales of the Co-ordinated Organisations. The annual basic salary will be EUR 83,888 NET of tax. ECMWF also offers a generous benefits package, including a flexible teleworking policy. The position is assigned to the employment category STF-PL as defined in the ECMWF Staff Regulations. Full details of salary scales and allowances available on the ECMWF website at, including the ECMWF Staff Regulations and the terms and conditions of employment. 

Starting date:              As soon as possible

Length of contract:   30 months, with the possibility of extension

Location:                      Bonn, Germany

As a multi-site organisation, ECMWF has adopted a hybrid organisation model which allows flexibility to staff to mix office and tele-working. 

Successful applicants and members of their family forming part of their households will be exempt from immigration restrictions.

Interviews by videoconference (MS Teams) are expected to take place shortly after the closing date of the vacancy announcement.

Who can apply 

Applicants are invited to complete the online application form by clicking on the apply button below. 

At ECMWF, we consider an inclusive environment as key for our success. We are dedicated to ensuring a workplace that embraces diversity and provides equal opportunities for all, without distinction as to race, gender, age, marital status, social status, disability, sexual orientation, religion, personality, ethnicity and culture. We value the benefits derived from a diverse workforce and are committed to having staff that reflect the diversity of the countries that are part of our community, in an environment that nurtures equality and inclusion. 

Applications are invited from nationals from ECMWF Member States and Co-operating States, as well as from all EU Member States. 

ECMWF Member and Co-operating States are: Austria, Belgium, Bulgaria, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Georgia, Germany, Greece, Hungary, Iceland, Ireland, Israel, Italy, Latvia, Lithuania, Luxembourg, Montenegro, Morocco, the Netherlands, Norway, North Macedonia, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United Kingdom. 

In these exceptional times, we also welcome applications from Ukrainian nationals for this vacancy.  

Applications from nationals from other countries may be considered in exceptional cases.