About
Andrew Castor
John Andrew — I go by Andrew
I am the Tech Operations Lead for Medical Missionaries of Divine Mercy, a Houston-based 501(c)(3) nonprofit that runs free medical clinics for underserved populations. The organization operates in the Cabecar indigenous community in Costa Rica and in Laredo, Texas.
My background is not clinical — I am a student who is comfortable on the Linux command line, but I came into this project without prior EMR experience. This was my fifth MMDM mission — my first was to Laredo in 2018 — and the first in which technology was my primary role rather than clinical support. That is not a credential gap; it is the actual shape of the challenge. The technical work is real, the clinical constraints are real, and the people who depend on the system are real.
My role is technical implementer and strategic analyst. Station leads hold clinical ground truth; I hold the infrastructure. Decisions that cross those lines get made together.
"There's a quiet dignity in being remembered, and if our technology can give that to even a fraction of the people we serve, that feels like a form of presence worth building."
— MMDM Costa Rica 2026 Newsletter
The Organization
Medical Missionaries of Divine Mercy (mmdm.org) is a 501(c)(3) nonprofit based in Houston, Texas. It sends traveling volunteer medical teams to provide free care to underserved communities. Services span registration, triage, medical, pediatrics, vision, and dental, with third-party pharmacy and counseling at most missions.
The organization ran on paper forms for years before this project began. Station leads have conducted 26 and 32 missions respectively on those paper forms. The EMR transition is not a replacement for their expertise — it is infrastructure that makes their expertise more legible and more recoverable.
What I Brought to This
What I Did Not Know Going In
I had not worked with an EMR before this project. I had not deployed clinical software before this project. I had not built a private PKI before this project, or designed forms for clinical workflows, or diagnosed a system failure mid-mission while a queue of patients was waiting.
That is what makes this record worth keeping. The journal is not a portfolio of things I already knew how to do. It is a record of learning under real constraints with real stakes.
Contact
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