Disclosed are some implementations of systems, apparatus, methods and computer program products for facilitating the validation of assessments in an eLearning environment. Validation is facilitated using an assessment definition that includes one or more application programming interfaces (APIs) and identifies, for each of the APIs, a corresponding plugin and handler. Each of the APIs is configurable to obtain at least one user response to a corresponding challenge task via the corresponding plugin and each handler is configurable to validate the user response returned via the corresponding API. The accuracy of the user response to each challenge task is determined via the corresponding handler identified within the assessment definition. APIs can include a third party API, enabling validation of user responses across different systems. The user's knowledge may be assessed based upon the accuracy of the user's responses to all of the challenge tasks.