Architecture Views

01 System ContextWho uses the platform, which external services it depends on, and what crosses the boundary — with no internal components shown. HTML · SVG · draw.io 02 High-Level ArchitectureThe shape of the system in one picture: clients hold a persistent authenticated socket, the core accepts and orders, and fanout drives delivery per device. HTML · SVG · draw.io 03 Layered ArchitectureWhat depends on what. Dependencies point downward only; delivery back to a device re-enters through the edge layer rather than reversing a dependency. HTML · SVG · draw.io 04 Container ArchitectureThe deployable units, their technology, and the protocol on every link — C4 level 2 for the messaging core. HTML · SVG · draw.io 05 Registration & Device OnboardingPhone-number sign-up end to end: verification, attestation, identity key generation, prekey publication and contact discovery. HTML · SVG · draw.io 06 Message Send and Delivery PathThe primary flow: compose, encrypt, accept, fan out, deliver and confirm — with the idempotency gate that makes a client retry harmless. HTML · SVG · draw.io 07 Delivery and Receipt State MatrixEvery message state, what triggers it, who emits it, what the sender sees, and how long the server keeps anything at all. HTML · SVG · draw.io 08 Fanout by Conversation ClassFour conversation classes, four fanout strategies — showing where the cost sits and why group messaging stays affordable at 1024 members. HTML · SVG · draw.io 09 Offline Queuing and Retry LoopThe loop that makes delivery survive a device being off, offline or asleep — and the acknowledgement that closes it. HTML · SVG · draw.io 10 Media Upload and Download PipelinePhotos, video, documents and voice notes: compressed and encrypted on device, stored as opaque bytes, distributed by CDN. HTML · SVG · draw.io 11 Presence, Typing and Push SignalsThree ephemeral signal classes and the privacy gate that decides whether any of them are visible at all. HTML · SVG · draw.io 12 End-to-End Encryption ArchitectureFrom device key material through asynchronous session setup to per-message ratcheting — and where the platform sits, which is outside the trust boundary. HTML · SVG · draw.io 13 Multi-Device Linking and SynchronisationLinking a companion device, seeding its history, and keeping four devices consistent without making the phone a relay. HTML · SVG · draw.io 14 Voice and Video Call ArchitectureWebRTC signalling over the existing chat socket, keys derived from the Signal session, and an SFU that forwards frames it cannot read. HTML · SVG · draw.io 15 Status and Stories PipelineEphemeral posts with an audience resolved at publish time, encrypted per post, and hard-deleted at 24 hours. HTML · SVG · draw.io 16 Search, History, Backup and RestoreWhere conversation data actually lives, what the platform can search, and how a user moves history to a new phone without the platform reading it. HTML · SVG · draw.io 17 Data Architecture and Ownership ZonesData grouped by who owns it and whether it can be rebuilt — the question that decides what a regional outage actually costs. HTML · SVG · draw.io 18 Core Data ModelThirteen entities covering accounts, devices, keys, conversations, envelopes, receipts and media — and the column that is conspicuously absent. HTML · SVG · draw.io 19 Integration and Interface CatalogueEvery way the platform touches another system, with the protocol and cadence on each interface and the direction of the call. HTML · SVG · draw.io 20 Security Trust ZonesFive zones in decreasing exposure, the attacks that arrive at each, and what stops them — with the flow crossing every boundary labelled. HTML · SVG · draw.io 21 Deployment and Multi-Region TopologyWhat runs where and what survives a failure: anycast edge, two active regions, three availability zones each, accounts pinned to a home region. HTML · SVG · draw.io 22 CI/CD and Environment ProgressionHow a change reaches production and what stops a bad one — including the gates that exist specifically because this system carries cryptography. HTML · SVG · draw.io 23 Observability and Service LevelsSix signal classes across five pipeline stages, each ending in a defined action — the matrix form makes a missing cell visible. HTML · SVG · draw.io