Are you currently writing any tests — unit, integration, or others?

Yes, I write tests to ensure the quality and stability of BI solutions. Mostly, these are integration tests that verify the correctness of data loading and transformation, as well as visualization in Tableau or PowerBI. Unit tests are less common in BI environments, but I use them to check scripts and functions, for example, written in Python or SQL.

An example of a simple Python test for checking a data transformation function:

def transform(data):
    return [x * 2 for x in data]


def test_transform():
    input_data = [1, 2, 3]
    expected = [2, 4, 6]
    assert transform(input_data) == expected

if __name__ == "__main__":
    test_transform()
    print("Test passed")