An engineer will most likely use IPerf to get detailed measurement data about the user's slow file transfers.
IPerf is a tool used for measuring network performance and bandwidth, and it can be used to measure the speed and throughput of file transfers from the remote office. It can also provide detailed information about the latency and jitter of the connection, which can be used to troubleshoot the slow file transfers. Reference:
CompTIA Network+ Study Manual (Chapter 10, Page 214).

Data center interconnect (DCI) is a solution that allows Layer 2 connectivity and data replication between geographically dispersed data centers. DCI can be implemented using various technologies, such as optical networks, MPLS, VPNs, or Ethernet. DCI can provide benefits such as improved disaster recovery, load balancing, resource pooling, and cloud services.
Reference:
Data Center Interconnect - CompTIA Network+ N10-008 Domain 1.4 - YouTube1 CompTIA Network+ Certification Exam Objectives, page 92

An NDA, or non-disclosure agreement, is a legal contract that binds an employee to keep certain information confidential and not share it with unauthorized parties. This information may include trade secrets, intellectual property, business strategies, customer data, or other sensitive or proprietary information that gives the company a competitive advantage. An NDA protects the company's interests and prevents the employee from disclosing or using the information for personal gain or malicious purposes1.
Reference
1 - 10 Types of Employment Contracts | Indeed.com