A practical reference for software engineers working in healthcare. Written from a developer's perspective — focused on what you need to know to build, integrate, and ship.
The notes below are organized like a book: a Preface, five thematic Parts of numbered Chapters that build on one another, and an Appendix for reference material. Read in order if you're new to healthcare IT. Jump to a specific chapter if you're hunting for a topic.
Orient yourself in the healthcare software landscape.
- Healthcare IT - Home — Big-picture index with tech analogies for every core concept
- Common Healthcare Workflows — Admit/discharge, lab orders, referrals, billing, and the events behind them
- EHR Landscape — The major Electronic Health Record vendors
The formats and vocabularies every healthcare integration speaks.
- Healthcare Data Standards — Overview tying HL7v2, FHIR, CCDA, and X12 together
- Medical Coding Systems — LOINC, SNOMED CT, ICD-10, CPT, RxNorm — the vocabularies clinical data is built from
- HL7v2 Essentials — The legacy pipe-delimited messages used inside hospitals
- FHIR Deep Dive — The modern REST/JSON API standard
- CCDA — The XML document format for clinical document exchange
You cannot ship in healthcare without these.
- HIPAA for Developers — The privacy law, BAAs, and what you must build to stay compliant
- Healthcare Authentication — SMART on FHIR (OAuth2 for healthcare apps)
Tools, vendors, and architectural patterns for wiring systems together.
- Mirth Connect — The most common open-source integration engine
- Integration Patterns — Hub-and-spoke, pub-sub, facade, bulk data, and more
- Epic Systems — The dominant US EHR and how to integrate with it
How data moves between separate organizations.
- Direct Messaging Protocol — Encrypted "email" for clinical documents
- Health Information Exchange (HIE) — Regional networks for sharing patient data, including state/regional HIEs in detail
- QHIN and TEFCA — The federal framework and the 8 designated national QHINs
- Kno2 — Managed API for Direct, HIE, TEFCA, and the PD/DQ/DR query workflow
- A. Healthcare Glossary — Acronyms and terms. Bookmark this; you'll come back constantly.
These are working developer notes — practical, opinionated, and code-first. Every chapter targets engineers building healthcare software, not clinicians or compliance officers. Expect:
- Real HL7 messages, real FHIR JSON, real curl calls
- Web-dev analogies (Stripe, OAuth, Kafka, GitHub Apps, etc.) for unfamiliar healthcare concepts
- "Beginner primer" callouts at the top of every chapter for fast orientation
- Cross-references to related chapters whenever concepts overlap
- Cross-references use Obsidian-style
[[wikilinks]]. On GitHub these don't render as clickable links — open the vault in Obsidian for full navigation, or use the table of contents above. - Read in order if new. Each Part builds on the previous one; chapters within a Part can be read sequentially.
- Jump around if experienced. Every chapter is self-contained enough to read alone.
- If something is wrong or missing, open a PR.