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Parth Parekh
STAGE 07CONTROLEXECUTION PLANE
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The control layer: one signal, many books

This is the layer the desk actually leans on at 09:16. A strategy publishes one master trade in a single lot. The control layer decides, per client, how large that becomes and which order-management system it has to leave through.

client accounts
20–30
brokers, one interface
5
WHAT I BUILTCONTROL

Built here.

  • 01

    A master-slave model: the strategy writes one master tradesheet at unit size, and each subscribed client's order is scaled from that master against the client's own capital and multiplier.

  • 02

    Routing that resolves, per client, which broker the account belongs to and therefore which OMS instance receives the order — the strategy never names a broker.

  • 03

    A routing cache for client subscriptions, funds and endpoints, refreshed on a timer and snapshotted to disk, so the order path keeps routing from same-day state when the client directory is unreachable — and marks those orders as having done so.

  • 04

    Client synchronisation for accounts that join a running strategy mid-session, mirroring either the day's filled legs or the whole book, as chosen.

  • 05

    Desk controls as first-class operations: pause, freeze, square-off previews and system-wide square-off, with a second factor on the destructive ones.

  • 06

    A local write-ahead queue: every order row commits locally first and replicates to the store behind it, so a database problem delays the record instead of rejecting the trade.

  • 07

    Per-minute margin and P&L snapshots per strategy and client through the session, for intraday forensics after the fact.

WHAT IT SURVIVESFAILURE MODES

Failure modes.

  • The client directory being unavailable, which falls back to same-day cached routing and refuses stale previous-day state outright.
  • A storage outage, which the order path never waits on.
  • One client or one host failing, which is isolated to its own lane instead of freezing the fan-out.

One decision becomes twenty to thirty client orders across five brokers without a trader logging into five terminals — and the screens that watch it are never allowed to sit on the order.

STACKON THIS STAGE