The stack¶

The stack stands with the internet at the top and the national registrations at the bottom.

                 resident / internet
                          |
                          v
    +-------------------------------------------+
    | PUBLIC DIGITAL SERVICES   (exposed edge)  |
    | websites and CMS, e-formulieren,          |
    | mijn-omgeving portals, payment            |
    | Seneca, SIMgroep, Exxellence, CARE,       |
    | Open Formulieren                          |
    +-------------------------------------------+
                          |
                          v
    +-------------------------------------------+
    | IDENTITY                                  |
    | DigiD, eHerkenning, eIDAS   (SAML / OIDC) |
    +-------------------------------------------+
                          |
                          v
    +-------------------------------------------+
    | COMMON GROUND   (plumbing)                |
    | ZGW REST: Zaken, Documenten, Catalogi,    |
    | Besluiten. Haal Centraal, NLX / FSC       |
    | legacy StUF SOAP alongside                |
    | orchestration: Decos JOIN, Visma Roxit    |
    | ZGW registration: Open Zaak               |
    +-------------------------------------------+
                          |
                          v
    +-------------------------------------------+
    | CORE / BACK-OFFICE   (behind the line)    |
    | Centric, PinkRoccade                      |
    | burgerzaken, financials                   |
    +-------------------------------------------+
                          |
                          v
    +-------------------------------------------+
    | BASE REGISTRATIONS                        |
    | BRP, BAG / BGT   (geo: Vicrea, PDOK)      |
    +-------------------------------------------+

The arrows are trust boundaries. Each crossing is a place where one layer takes on trust what another hands it: an identity assertion, a prefilled field, an API call made on a resident’s behalf. The top is thin and public. The core at the bottom is deep, quiet, and reachable only through everything above it.