Nite ize makes a variety of products, for example https://www.amazon.com/dp/B00KSKY0KS/ref=cm_sw_r_cp_apa_glt_fabc_TCRHDJ7MWV0704H72FHG

If webbing is ok instead of rope then there are many buckets, cam, or ratchets. https://www.amazon.com/dp/B0774KKHWF/ref=cm_sw_r_cp_apa_glt_fabc_0C5TMQ242E8N9GYQ4BN5

There are tons of rigging, sailing, and climbing products but you'd need to describe your use case in more detail.

There are also knots like a clove hitch that can be used with a carabineer, tensioned, and adjusted very easily.