http://www.l24qgjfin436fqou22lusrbqmvoysp6jeey5fdn2fr7zzzv2e35jwrid.onion
Typically we're looking at two or three days for small systems, maybe two weeks for large systems, assuming that design work does not uncover deeper issues or questions (such as discovering that various data sources do not in fact join up, data quality issues serious enough to prevent implementation, and so on), and that client engineers are available without undue delay for questions.