A UUID is stable by construction — the id itself never changes. What is not stable, and what teams get wrong, is the mapping from a resource in one environment to the same resource in another. Dev, staging, and production each have their...
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A FHIR integration engine is the layer that turns FHIR from a spec into a working bridge between systems. Every non-trivial healthcare deployment ends up with one, and the choice shapes operational ergonomics for years. The 2026 market has
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UUID collisions are theoretically possible and effectively impossible with a properly-generated v4 across every FHIR workload short of the entire industry writing to one namespace. The real problem in multi-tenant deployments is not the...
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UUID v4 is the workhorse — 122 bits of randomness in a fixed layout, cryptographically strong when generated with a proper RNG, no ordering information. UUID v7 is newer — it embeds a millisecond timestamp in the high bits so ids sort by...
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Bundle.entry.fullUrl is where a Bundle assembles entries that reference each other atomically. The urn:uuid: prefix in that field is what makes cross-entry references work in a transaction Bundle where the resource ids do not exist yet. It...
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FHIR has two id-shaped fields on almost every resource, and they do different jobs. Resource.id is the server's logical id — where the resource lives. Resource.identifier[] is the business identity — the MRN, order number, or external...
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Every FHIR resource has a logical id. It can be a UUID, a sequential integer, a natural business key, or anything else that satisfies the id datatype rules. The choice is not academic. A resource id is what every reference in the graph...
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SMART on FHIR app reviewers (the people running app-store-style review programs for SMART apps inside EHR vendor marketplaces) have a validation workload that looks nothing like a developer's IDE pass. The review has to check conformance, s
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The FHIR validator market has a strong open-source baseline and a meaningful commercial layer on top, and most procurement decisions get framed as either-or when the honest answer is usually both. The cost story, the support story, and the
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Bulk data submissions are the validation use case where single-resource validators show their limits. An NDJSON file with a million Patient and Observation resources is a throughput problem before it is a validation problem, and a validator