He was the son of masonry foreman. Until 1837, Leins attended the Friedrich-Eugens-Gymnasium in Stuttgart, then served an apprenticeship at a local architectural firm. From 1837 to 1840, he lived in Paris, where he found employment with
Henri Labrouste, while he received training from
Eugène Flachat and
Jules Petiet. Upon returning home, he passed the state exam for
structural engineering. His personal papers and original drawings are preserved in the Stuttgart University Library. ==Major projects ==