This research provides an exhaustive investigation into the architectural paradigms and mitigation strategies required to ensure reliability in advanced semiconductor technologies, specifically focusing on SRAM-based Field Programmable Gate Arrays (FPGAs) and multi-core processor environments. As transistor dimensions continue to shrink into the sub-nanometer regime, the susceptibility of integrated circuits to radiation-induced soft errors, such as Single Event Upsets (SEUs), has increased exponentially. This article synthesizes foundational theories of fault tolerance with contemporary implementation techniques, including Triple Module Redundancy (TMR), Dual-Core Lockstep (DCLS) configurations, and hybrid non-intrusive error detection. By analyzing the intersection of safety-critical automotive zonal controllers and nuclear instrumentation systems, the study evaluates the trade-offs between hardware overhead, latency, and error coverage. The methodology adopts a descriptive analytical approach, detailing the evolution from traditional redundancy to advanced algorithmic-based fault tolerance and control-flow monitoring. Findings suggest that while hardware redundancy remains the gold standard for spatial applications, hybrid software-hardware approaches offer a more power-efficient solution for terrestrial automotive and industrial sectors. The discussion further explores the shift toward zonal control in vehicular networks, emphasizing the necessity of timely error detection to maintain functional safety in autonomous systems.