  Quantum information processing is steadily progressing from a purely academic
discipline towards applications throughout science and industry. Transitioning
from lab-based, proof-of-concept experiments to robust, integrated realizations
of quantum information processing hardware is an important step in this
process. However, the nature of traditional laboratory setups does not offer
itself readily to scaling up system sizes or allow for applications outside of
laboratory-grade environments. This transition requires overcoming challenges
in engineering and integration without sacrificing the state-of-the-art
performance of laboratory implementations. Here, we present a 19-inch rack
quantum computing demonstrator based on $^{40}\textrm{Ca}^+$ optical qubits in
a linear Paul trap to address many of these challenges. We outline the
mechanical, optical, and electrical subsystems. Further, we describe the
automation and remote access components of the quantum computing stack. We
conclude by describing characterization measurements relevant to digital
quantum computing including entangling operations mediated by the
Molmer-Sorenson interaction. Using this setup we produce maximally-entangled
Greenberger-Horne-Zeilinger states with up to 24 ions without the use of
post-selection or error mitigation techniques; on par with well-established
conventional laboratory setups.
