In this role, you will:

• write computer code, using both C++ and R, to refactor lavaan’s internal processes, to improve speed, modularity, and scalability;
• investigate diagnostic properties (e.g., speed, accuracy) of the updated lavaan package, comparing performance to the current package;
• publish about the updated package in the Journal of Statistical Software, as an update to Rosseel’s (2012) frequently cited paper introducing lavaan;
• develop documentation and educational materials with collaborators at other universities.
• Contribute to teaching tasks (15–25% of the full-time appointment)

We are looking for an enthusiastic researcher:

• with at least a master’s degree (preferably a PhD) and extensive training in quantitative statistical methods (particularly SEM). A degree in behavioural sciences (e.g., psychology) is preferred, but we welcome applications from other backgrounds (e.g., mathematics, computer science), if they also have some familiarity with behavioural sciences;
• who can convert (statistical) algorithms to high-quality source code (at least in R, but C++ is an asset);
• with experience working with version-control software like Git (preferably, experience can be demonstrated with activity on a public repository like GitHub);
• with strong academic skills, demonstrated by peer-reviewed empirical publications (or unpublished but institutionally archived thesis/dissertation), written in English (preferably as first author, or at least with writing contributions indicated via the publication’s CRediT statement);
• with a strong commitment to practicing open-science, demonstrated by using a public repository (e.g., the Open Science Framework) to host the SEM software code used for an empirical study (preferably utilizing lavaan).

We offer a fixed-term employment contract for 38 hours per week (1.0 fte), beginning on or before September 1, 2026 (starting as soon as possible after September 1 may be accommodated, depending how soon the applicant can contribute to teaching). The position is initially for one year, with the possibility of extension for a second year subject to a positive evaluation. However, urgent financial and/or organisational reasons may be reason not to continue the employment contract. The position can be carried out on a part-time basis, in which case the duration of the contract will be extended pro rata. The maximum duration of the project is four years. Your salary, depending on relevant experience at the start of employment, ranges from €3,546 to €6,433 gross per month (salary scale 10 - 11) based on full-time employment (38 hours per week), excluding an 8% holiday allowance and an 8.3% year-end bonus. The Collective Labour Agreement for Dutch Universities (Cao Nederlandse Universiteiten) applies. There is a working budget that will allow for international travel, to attend conferences and workshops.

We offer:

• A role in which initiative and input are highly valued;
• An enthusiastic and welcoming team that is open to new colleagues and enjoys computers, research methods, and statistics;
• An inspiring academic and international work environment in the heart of Amsterdam;
• A large (inter)national network of SEM researchers;
• An opportunity to help shape the future of the lavaan ecosystem.