The concept of defence in depth is built on layered security—ensuring that if one control fails, others are in place to detect, delay, or stop an attack. Unfortunately, many organisations invest heavily in securing the perimeter but leave internal networks far less protected, often described as having a “hard outer shell with a soft core.” Internal assessments help reveal these blind spots by identifying vulnerabilities, misconfigurations, and pathways that an attacker could exploit after gaining initial access. By simulating real-world attack scenarios from inside the network, this assessment exposes gaps that traditional perimeter-focused tests often miss. The insights gained enable organisations to improve their internal defences, reduce the risk of lateral movement, and build a more resilient, layered security posture.