  Distributed digital infrastructures for computation and analytics are now
evolving towards an interconnected ecosystem allowing complex applications to
be executed from IoT Edge devices to the HPC Cloud (aka the Computing
Continuum, the Digital Continuum, or the Transcontinuum). Understanding
end-to-end performance in such a complex continuum is challenging. This breaks
down to reconciling many, typically contradicting application requirements and
constraints with low-level infrastructure design choices. One important
challenge is to accurately reproduce relevant behaviors of a given application
workflow and representative settings of the physical infrastructure underlying
this complex continuum. We introduce a rigorous methodology for such a process
and validate it through E2Clab. It is the first platform to support the
complete experimental cycle across the Computing Continuum: deployment,
analysis, optimization. Preliminary results with real-life use cases show that
E2Clab allows one to understand and improve performance, by correlating it to
the parameter settings, the resource usage and the specifics of the underlying
infrastructure.
