While integrating Bulma with other front-end libraries or frameworks is generally smooth, there are a few considerations and challenges to keep in mind:

Class Naming Conflicts : Bulma uses its own set of class names for styling elements. When using Bulma with other CSS frameworks or custom styles, there might be conflicts in class names, leading to unintended style overrides or unexpected behavior.

Specificity Issues : In CSS, specificity determines which styles are applied to an element when conflicting rules exist. If your custom styles or another framework's styles have higher specificity than Bulma's classes, they might override Bulma's styles unintentionally.

Responsive Design Consistency : When combining Bulma with other frameworks or custom styles that have different approaches to responsive design, achieving a consistent and coherent responsive layout across all components might require careful adjustments and testing.

CSS File Size : If using Bulma alongside other CSS frameworks, the cumulative file size might increase. This could impact page load times, so it's essential to consider optimizing and minimizing unnecessary stylesheets for better performance.
Framework Interoperability : Some JavaScript frameworks or libraries might have their own ways of handling components, styles, or layouts. Ensuring seamless interoperability between Bulma and these frameworks might require additional effort and potential customizations.

Namespace Clashes : In component-based frameworks like React or Vue.js, conflicts might arise between Bulma's class names and component names. Using scoped styles, aliasing, or specific class naming conventions can help mitigate this issue.

Customization Challenges : When heavily customizing Bulma or using its utility classes extensively, maintaining consistency and avoiding conflicts with custom styles or other frameworks might become challenging, requiring a systematic approach to manage modifications and overrides.

Testing and Debugging : Integration with multiple frameworks or libraries might lead to complex scenarios during testing and debugging. Isolating issues arising from conflicts or unexpected behavior could take more effort in such cases.