Strategic DDD for Commodities Trading domain¶
From a DDD perspective, commodities trading decomposes into bounded contexts around trade, risk, logistics, finance, compliance, and analytics.
- Entities & Aggregates manage core business objects (Trade, Shipment, Settlement, Portfolio).
- Value Objects model immutable concepts (Price, Quantity, Currency).
- Domain Events capture state transitions critical to business processes.
- Context Maps define how subdomains collaborate.
Core Domain & Subdomains¶
At its heart, commodities trading is about managing trades and risks across physical flows and financial instruments. We can split the domain into subdomains:
- Trade Capture & Deal Lifecycle (core)
- Risk Management (core)
- Logistics & Operations (supporting)
- Financing & Settlement (supporting)
- Compliance & Reporting (generic/subdomain)
- Analytics & Decision Support (supporting/strategic)
Strategic Design¶
- Core Domain: Trade Capture & Risk Management (where competitive advantage lies).
- Supporting Domains: Logistics, Financing, Analytics (specialized but not unique).
- Generic Domains: Compliance, Reporting (mandatory but commoditized).
This informs build vs. buy decisions — e.g., build risk engine in-house, but buy compliance modules.
Bounded Contexts¶
Each subdomain can be modeled as a bounded context with its own ubiquitous language and models.
Trade Capture Context¶
- Entities:
Trade,Counterparty,Instrument,Contract - Value Objects:
Price,Quantity,TradeDate,TradeId - Aggregates:
Trade(root, holds trade lines, instrument, counterparty, status) - Events:
TradeCaptured,TradeAmended,TradeCancelled - Services:
TradeValidationService,TradeBookingService
Risk Management Context¶
- Entities:
Position,Exposure,RiskLimit,Portfolio - Value Objects:
MarkToMarket,VaR,ScenarioResult - Aggregates:
Portfolio(root for positions & exposures) - Events:
PositionUpdated,LimitBreached,PnLCalculated - Services:
RiskCalculationService,MarketDataFeed
Logistics Context¶
- Entities:
Shipment,StorageFacility,InventoryLot - Value Objects:
Quantity,Location,Incoterms - Aggregates:
Shipment(root; includes lots, schedules, destination) - Events:
ShipmentScheduled,ShipmentDelivered,InventoryAdjusted - Services:
LogisticsSchedulingService,InventoryReconciliationService
Financing & Settlement Context¶
- Entities:
Settlement,PaymentInstruction,LetterOfCredit - Value Objects:
Currency,Amount,SettlementDate - Aggregates:
Settlement(root; holds trade reference, payment details, status) - Events:
PaymentSettled,LCExpired,SettlementFailed - Services:
SettlementProcessingService,BankIntegrationService
Compliance Context¶
- Entities:
RegulatoryReport,AuditLog,KYCRecord - Value Objects:
LEI,UTI,Timestamp - Aggregates:
Report(root) - Events:
ReportGenerated,KYCFlagged - Services:
RegulatoryReportingService,AuditTrailService
Analytics Context¶
- Entities:
Curve,Scenario,Forecast - Value Objects:
ForwardPrice,StressFactor - Aggregates:
MarketAnalysis - Events:
CurveGenerated,ScenarioRunCompleted - Services:
PricingEngine,ForecastingService
Context Map¶
title Commodities Trading Domain - Context Relationships
rectangle "Trade Capture" as TC
rectangle "Risk Management" as RM
rectangle "Logistics" as LG
rectangle "Financing & Settlement" as FS
rectangle "Compliance" as CP
rectangle "Analytics" as AN
TC -[#blue]-> RM : Customer-Supplier
TC -[#blue]-> LG : Customer-Supplier
TC -[#blue]-> FS : Customer-Supplier
RM <-[#green]-> AN : Partnership
FS -[#orange]-> CP : Open Host Service
TC -[#purple]-> CP : Published Language
RM -[#purple]-> CP : Published Language
LG -[#purple]-> CP : Published Language
legend right
== Legend ==
Blue: Customer-Supplier
Green: Partnership
Orange: Open Host Service
Purple: Published Language
endlegend
Bounded contexts interact through integrations and translations:
- Trade Capture → Risk Management: trades feed into positions & exposures.
- Trade Capture → Logistics: physical trades trigger shipment creation.
- Trade Capture → Financing: financial obligations flow into settlements.
- Risk Management ↔ Analytics: pricing, curves, scenarios enrich valuations.
- Financing → Compliance: settlements must generate reports and logs.
- All contexts → Compliance: audit trail is ubiquitous.
Trade Capture → Risk Management¶
- Pattern: Conformist / Customer-Supplier
- Risk depends on trade data and has to conform to the model exposed by Trade Capture.
- Implication: Risk Management consumes trades, but does not redefine them.
Trade Capture → Logistics¶
- Pattern: Customer-Supplier
- Logistics depends on physical trade details (quantities, delivery terms).
- Implication: Logistics must align with trade capture’s definitions of quantity, commodity, counterparty.
Trade Capture → Financing & Settlement¶
- Pattern: Customer-Supplier
- Settlement requires trade details to generate obligations.
- Implication: Trade Capture is the source of truth; Finance aligns to its schema.
Risk Management ↔ Analytics¶
- Pattern: Partnership
- Risk and Analytics collaborate — risk engines depend on analytics (curves, scenarios), analytics depends on trades and positions.
- Implication: Shared model, high collaboration.
Financing & Settlement → Compliance¶
- Pattern: Open Host Service
- Compliance “subscribes” to settlement events and consumes data for regulatory reporting.
- Implication: Compliance is generic and should not impose its model upstream.
Trade Capture → Compliance¶
- Pattern: Published Language
- Compliance consumes trade data for audit and regulatory reports.
- Implication: A shared vocabulary (UTI, LEI, trade identifiers) ensures consistency.
Risk Management → Compliance¶
- Pattern: Published Language
- Compliance consumes risk metrics (VaR, exposures).
- Implication: Needs standardized reporting language.
Logistics → Compliance¶
- Pattern: Published Language
- Compliance consumes shipment and delivery events.
- Implication: Compliance translates delivery events into regulatory language (e.g., REMIT).
Event Storming¶
Key domain events across contexts:
TradeCaptured,TradeConfirmed,TradeAmendedPositionUpdated,LimitBreached,PnLCalculatedShipmentScheduled,ShipmentDeliveredPaymentSettled,LCExpiredReportGenerated,KYCFlagged
These events form the backbone of an event-driven architecture.