This volume presents the thoroughly revised and extended lecture notes of the first SusTrainable Summer School on Promoting Sustainability as a Fundamental Driver in Software Development Training and Education, which took place in Rijeka, Croatia, during July 4-8, 2022. The summer school was organized in the context of the Erasmus+ Strategic Partnership for Higher Education, funded by the European Union and coordinated by the University of Coimbra, Portugal. The focus of the event was on the education of software engineers to consider sustainability in all aspects of the software engineering process, with the aim of limiting the energy footprint of ICT infrastructures. The 11 papers included in the volume cover the following topics: green computing for the Internet of Things; verified software in Web-based virtual environments; sustainable programming in the Julia language; algorithms for sustainable system topologies; energy debt; the effects of feature reduction on machine learning model energy consumption; multicriteria decision methods for sustainable software development; using strong types in C++ for long-term code management; temporal-logic automated solutions for sustainable educational progress; energy-driven software engineering; and group based actor model middleware with UDP protocol.