We’ve just opened a call for applications for a 2-year (possible extension to 4-year) postdoc position in our Oxford office, working on declarative scientific modelling in the context of ecological systems.
In the context of ecological systems and their resilience, can we provide mathematical scaffolding to enable broader communication and understanding between ecologists, policymakers, ethics and oversight boards, and other key stakeholders, all with differing technical backgrounds? How does this relate to the story of formal declarative modelling phrased in terms of category theory? What sorts of tools are useful to build here, and what affordances should they make, and how do people want to use them?
I’m excited about these questions, and a large part of my excitement comes from the variety of work that they entail: fundamental research in category theory, conversations across academic boundaries with experts in ecology and policymaking and ethics oversight boards, software development supported by the members of our research software engineering team, and probably quite a few things that I haven’t even thought of.
We are soon to start work on these questions, and others like them that will naturally arise, in close collaboration with teams of ecologists and other domain specialists. As part of this, we’re hiring for a 2-year postdoc position.
Call for applications: UK-2026-Eco
To understand what sort of work this position entails, I think it’s helpful to look back at some of the work that people at Topos, and our collaborators, have been doing. Over the past year or so, I’ve been working as part of the CatColab team, looking at how we can take some of the foundational research work happening at Topos on declarative formal modelling (Lambert and Patterson 2024; Libkind and Myers 2025) and embed it into use-case contexts, and then . Historically, a lot of this work has been contextualised within public health and epidemiology: AlgebraicPetri.jl (Libkind et al. 2022) is a core example, as is the AIM workshop that we ran at the start of this year with the US NSF Center for Analysis and Prediction of Pandemic Expansion (APPEX). More recently, we’ve been working with IDEMS and CASAS on software for modelling complex systems arising in the study of invasive species (Simmons et al. 2025).
I sketched out the story of one particular research thread in some blog posts earlier this year: the mathematical side (Part 11) and the software side (Part 2) of an extension of mass-action semantics. There I talked through what this process of implementing new features into CatColab looks like, and how it involves a good amount of back-and-forth, going from category theory to software to the domain in question and back again. In particular, it involves working within a group of diverse expertise, acting more as a translator than as a direction-setter.
To give a brief example of what sort of work I expect we’ll be doing, consider the formalism of Bayesian networks. These can be useful in exploring the impact of changes to an ecosystem, providing a graphical language to express statements and pose questions in terms of conditional probabilities. So what is a good categorical syntax-semantics description of these networks? How can we understand quantitative analyses of these networks in analogy to how we understand ODE semantics of, say, Petri nets? What would it look like to add the capability to build these in CatColab? Can we actively enable the practice of participatory modelling through co-designed software?
If this sounds interesting to you and you’re looking for a postdoc position, then I strongly encourage you to take a look at the job advert and apply!
Call for applications: UK-2026-Eco
References
Footnotes
This post is actually rather light on the more technical details, but hopefully serves as a good indicator of the types of questions that we are led to consider. Something more technical, arising from the same research thread, is Evan’s CatColab RFC on set-theoretic models of double theories and their application to ODE semantics: RFC-0001.↩︎