SPOTLIGHT is a time-domain survey instrument to perform real-time 24/7 commensal search for Fast Radio Bursts (FRBs) and Pulsars with the GMRT [1]. It uses a state-of-the-art GPU-based compute cluster which is expected to generate 2000 post-correlation beams in real-time. We present here details of four main components of the SPOTLIGHT system - 1. the design and architecture of the correlator and post-correlation beamformer, 2. real-time beam synthesis ensuring precise beam shape and tiling of the field-of-view, providing on-the-fly localisation of the burst with up to arc-second accuracy, 3. online control and monitoring system to ensure piggy-back operation with the main backend, the GMRT Wideband Backend (GWB) [2], 4. real-time web-based monitoring tool that visualises the run-time status of the SPOTLIGHT system to track the proper run-time functionality of this fully automated system.