Systems and methods for hydroprocessing a heavy oil feedstock with reduced heavy oil deposits, the system employs a plurality of contacting zones and separation zones zone under hydrocracking conditions to convert at least a portion of the heavy oil feedstock to lower boiling hydrocarbons, forming upgraded products. The contacting zones operate under hydrocracking conditions, employing a slurry catalyst for upgrading the heavy oil feedstock, forming upgraded products of lower boiling hydrocarbons. In the separation zones, upgraded products are removed overhead and optionally, further treated in an in-line hydrotreater. At least a portion of the non-volatile fractions recovered from at least one of the separation zones is recycled back to the first contacting zone in the system, in an amount ranging between 3 to 50 wt. % of the heavy oil feedstock.