Software application development is a complex activity which involves various actors and organizations in what is called the software supply chain. The evolution of the software supply chain led to numerous benefits such as profit maximization, code mutualization, and the optimization of lead times. However, the complexity of the software supply chain results in multiple security issues and attacks because compromises are highly prevalent. An attacker that compromises a single link (e.g., by maliciously modifying the software) in the software supply chain, can harm users of this software and this attack technique is frequently being exploited to attack high profile companies. We can provide a holistic and effective security solution to the software supply chain only if its security state and features are well understood. We discuss how we can achieve strong resilience of the software supply chain to cyberthreats. Next, we propose a holistic end-to-end security approach for the software supply chain.