Oleksii P. focused on strengthening Verifiable Credential handling in the affinidi/affinidi-ssi-dart repository by enforcing strict type validation within the VcDataModelV2 class. Using Dart, he implemented logic to ensure the 'type' field always includes 'VerifiableCredential', throwing an SsiException if this requirement is not met. This approach improved data integrity and aligned the model with verifiable data standards. Oleksii also developed comprehensive unit tests to cover the new validation scenario, reducing the risk of future regressions. His work demonstrated depth in API validation, data modeling, and testing, directly enhancing the reliability of credential issuance and verification flows.