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VETA VETA Trading Platform

Architecture

VETA is a multi-service trading platform connected by a Redpanda message bus (Kafka-compatible). The React frontend talks to a single API Gateway — the only service the browser can reach. Everything else communicates via bus topics.

System architecture

Section titled “System architecture”
graph TB
    subgraph Client["Client Layer"]
        FE["React Frontend<br/><i>Vite / Electron</i>"]:::client
    end


    subgraph Gateway["API Gateway :5011"]
        GW["Gateway (BFF)<br/><i>WebSocket hub + HTTP proxy</i>"]:::gateway
    end


    subgraph Bus["Redpanda Message Bus :9092"]
        KAFKA["Kafka-compatible pub/sub"]:::bus
    end


    subgraph Trading["Order Management"]
        OMS["OMS :5002<br/><i>Validation + routing</i>"]:::trading
        EMS["EMS :5001<br/><i>Execution + FIX bridge</i>"]:::trading
        RISK["Risk Engine :5032<br/><i>6 pre-trade checks</i>"]:::risk
    end


    subgraph Algos["Algo Strategies"]
        LIMIT["LIMIT :5003"]:::algo
        TWAP["TWAP :5004"]:::algo
        POV["POV :5005"]:::algo
        VWAP["VWAP :5006"]:::algo
        ICEBERG["ICEBERG :5021"]:::algo
        SNIPER["SNIPER :5022"]:::algo
        AP["ARRIVAL_PRICE :5023"]:::algo
        MOM["MOMENTUM :5025"]:::algo
        IS["IS :5026"]:::algo
    end


    subgraph Market["Market Data"]
        MSIM["Market Sim :5000<br/><i>GBM price engine</i>"]:::market
        MDS["Market Data :5015<br/><i>Alpha Vantage / Polygon</i>"]:::market
        MDA["Adapters :5016<br/><i>Earnings + economic</i>"]:::market
    end


    subgraph Analytics["Analytics & Intelligence"]
        ANA["Analytics :5014<br/><i>Black-Scholes / Monte Carlo</i>"]:::analytics
        FE_ENG["Feature Engine :5017"]:::analytics
        SIG["Signal Engine :5018"]:::analytics
        REC["Recommendation :5019"]:::analytics
        SCEN["Scenario Engine :5020"]:::analytics
    end


    subgraph Persistence["Data Stores"]
        JOURNAL["Journal :5009<br/><i>PostgreSQL</i>"]:::storage
        FIXARC["FIX Archive :5012<br/><i>Execution reports</i>"]:::storage
        USER["User Service :5008<br/><i>OAuth2 + RBAC</i>"]:::storage
        REPLAY["Session Replay :5031<br/><i>rrweb recordings</i>"]:::storage
    end


    subgraph Microstructure["Market Microstructure"]
        FIXEX["FIX Exchange :9880<br/><i>Matching engine</i>"]:::fix
        DARK["Dark Pool :5027"]:::fix
        CCP["CCP :5028<br/><i>Central clearing</i>"]:::fix
        RFQ["RFQ :5029<br/><i>Request for quote</i>"]:::fix
    end


    subgraph Support["Support Services"]
        NEWS["News :5013<br/><i>Sentiment scoring</i>"]:::support
        LLM["LLM Advisory :5024<br/><i>Ollama</i>"]:::support
        OBS["Observability :5007"]:::support
    end


    FE <-->|"WebSocket + HTTP"| GW
    GW <-->|"pub/sub"| KAFKA
    KAFKA --- OMS
    OMS -->|"POST /check"| RISK
    OMS -->|"orders.routed"| KAFKA
    KAFKA --- LIMIT & TWAP & POV & VWAP & ICEBERG & SNIPER & AP & MOM & IS
    KAFKA --- EMS
    EMS --- FIXEX
    KAFKA --- JOURNAL & FIXARC
    GW -->|"auth validate"| USER
    KAFKA --- MSIM
    KAFKA --- ANA & FE_ENG & SIG & REC & SCEN
    KAFKA --- NEWS & LLM & OBS
    KAFKA --- DARK & CCP & RFQ
    KAFKA --- MDS & MDA
    KAFKA --- REPLAY


    classDef client fill:#818cf8,stroke:#6366f1,color:#fff
    classDef gateway fill:#f59e0b,stroke:#d97706,color:#000
    classDef bus fill:#64748b,stroke:#475569,color:#fff
    classDef trading fill:#22c55e,stroke:#16a34a,color:#000
    classDef risk fill:#ef4444,stroke:#dc2626,color:#fff
    classDef algo fill:#38bdf8,stroke:#0ea5e9,color:#000
    classDef market fill:#a78bfa,stroke:#8b5cf6,color:#000
    classDef analytics fill:#fb923c,stroke:#f97316,color:#000
    classDef storage fill:#2dd4bf,stroke:#14b8a6,color:#000
    classDef fix fill:#f472b6,stroke:#ec4899,color:#000
    classDef support fill:#94a3b8,stroke:#64748b,color:#000

Colour key

Section titled “Colour key”
ColourGroupServices
🟣 PurpleClientReact Frontend
🟡 AmberGatewayAPI Gateway (BFF)
🟢 GreenTradingOMS, EMS
🔴 RedRiskRisk Engine
🔵 BlueAlgos9 algo strategies
🟣 VioletMarket DataMarket Sim, Market Data, Adapters
🟠 OrangeAnalyticsAnalytics, Feature/Signal/Recommendation/Scenario engines
🟢 TealStorageJournal, FIX Archive, User Service, Session Replay
🩷 PinkMicrostructureFIX Exchange, Dark Pool, CCP, RFQ
⚪ GreySupportNews, LLM Advisory, Observability

Order flow

Section titled “Order flow”
sequenceDiagram
    actor Trader
    participant FE as Frontend
    participant GW as Gateway
    participant Bus as Redpanda
    participant OMS
    participant Risk as Risk Engine
    participant Algo as Algo Strategy
    participant EMS
    participant FIX as FIX Exchange
    participant Journal


    Trader->>FE: Submit order
    FE->>GW: WebSocket submitOrder
    GW->>Bus: orders.new
    Bus->>OMS: orders.new
    OMS->>OMS: Validate role, desk, limits
    OMS->>Risk: POST /check
    Risk-->>OMS: {allowed: true}
    OMS->>Bus: orders.submitted
    OMS->>Bus: orders.routed
    Bus->>Algo: orders.routed
    Algo->>Bus: orders.child (slice)
    Bus->>EMS: orders.child
    EMS->>FIX: Execute
    FIX-->>EMS: Fill
    EMS->>Bus: orders.filled
    Bus->>Journal: Persist
    Bus->>GW: Push to client
    GW-->>FE: WebSocket orderFilled
    FE-->>Trader: Blotter updated

Bus topics

Section titled “Bus topics”
CategoryTopics
Tradingorders.new, orders.submitted, orders.routed, orders.child, orders.filled, orders.expired, orders.rejected, orders.cancelled
Algoalgo.heartbeat
FIXfix.execution
Newsnews.feed, news.signal
Intelligencemarket.features, market.signals, market.recommendations

Authentication

Section titled “Authentication”

Sessions are stored as veta_user HTTP-only cookies set by the User Service via OAuth2 authorization-code flow with PKCE. The Gateway validates this cookie on every request (cached 10 seconds). The OMS independently fetches limits from the User Service (cached 30 seconds).

Roles: trader, desk-head, risk-manager, admin, compliance, sales, external-client, viewer. Only trader can submit orders.

See RBAC & Permissions and Trading Styles for details.