In December 2019, the Bill and Melinda Gates Foundation convened a workshop examining four education systems that have worked to build coherence across their systems, as viewed by “insiders” who played a significant role in carefully studying, designing, or maintaining the systems. This information note summarizes the knowledge shared at the workshop and was produced at the request of key stakeholders at the meeting. It is intended for the benefit of the participants and those who may be designing systems interventions or research, especially around the issue of the "instructional core" and the coherence among the various elements of the instructional core. The note is presented as an informal contribution.