Tobias Lidskog contributed to the bmuschko/rewrite-migrate-java and moderneinc/rewrite-recipe-starter repositories, focusing on Java migration and code reliability. He enhanced Jakarta EE migration recipes by pinning EE9 and EE10 dependencies, aligning them with umbrella releases to prevent version mismatches and reduce compilation or runtime errors. In the rewrite-recipe-starter project, Tobias corrected MethodMatcher syntax for ArrayList initialization, stabilizing unit tests and improving the reliability of collection mutation logic. His work demonstrated strong skills in Java, dependency management, and refactoring, addressing nuanced migration and testing challenges while ensuring maintainable, stable codebases for future development and safer feature delivery.