fsi-capital-oms

name	fsi-capital-oms
description	Case study of a cloud-native Order Management System (OMS) for capital markets / securities firms (資本市場 OMS, オーダー管理システム, 証券会社 受発注), based on real domestic and overseas brokerage OMS architectures. It shows how to balance the latency / scalability / high-availability trilemma by separating "order receipt & fill" from "order placement & execution" and connecting them with a low-latency messaging tier (Amazon ElastiCache for Redis / Redis Streams), plus AWS Outposts for exchange-proximity execution and AWS Auto Zone Shift for AZ failover. Use this skill when designing or reviewing an OMS / EMS / low-latency trading platform on AWS for a securities firm (証券取引システム, トレードライフサイクル, 低レイテンシー, 取引所連携), or when the user references BLEA for FSI capital-oms.
license	MIT No Attribution
metadata	{"author":"aws-jp-fsi-sa","version":"1.0"}

FSI Capital Market OMS (資本市場 OMS)

Workload Overview

This is a case study (not a deployable reference implementation) describing a cloud-native architecture for a securities firm's Order Management System (OMS) — the core system that sits in the front-to-middle layer of a brokerage's system landscape. The design is modeled on real OMS architectures currently running in domestic and overseas securities firms, and is shaped to meet the latency and availability requirements those firms demand.

Scenario. The OMS accepts orders from retail investors, institutional investors, and traders, manages fills, and places orders to exchanges. It also delivers real-time market information (price movements, quotes) received from information vendors to investors. During trading hours the front-to-middle system performs real-time processing of customer orders and provisional add/subtract of positions, balances, and buying power. A separate back-office system — outside this OMS scope — receives and processes final settlement data from exchanges and clearing houses after the market closes, computes confirmed values, and transfers that confirmed data to the front-to-middle system via overnight batch so it can be refreshed before the next business day.

Purpose and significance. Brokerage OMSs face a trilemma of latency, scalability, and high availability. Historically each firm developed its own OMS and maintained it on-premises for a long time; large systems still commonly run on mainframes. The purpose of this reference architecture is to provide guidance for a cloud-native OMS that achieves the optimal balance across that trilemma according to each firm's diversifying needs.

Business drivers / challenges. Recent sharp growth in trading volume drives expectations for cloud adoption to enable flexible capacity adjustment and cost optimization of the order-receipt/placement system. Three challenges are called out:

• Latency requirement. To minimize price slippage between order acceptance and execution and to raise the probability of filling at the best quote, extremely low latency is required. Firms traditionally used exchange colocation services or same-datacenter placement, but as products and investor services diversify, uniformly spending large cost to prioritize latency above all else no longer always has the best return on investment.
• Scalability. Continuously increasing trading volume and unpredictable sharp peaks during market events widen the gap between required capacity at peak versus normal times, making the cost of securing peak-handling resources a challenge.
• High availability. As securities trading grows in importance as social infrastructure, the availability requirement for the OMS — the center of the trade lifecycle — is becoming ever more stringent.

Real cloud-native OMS references cited by the case study: Vanguard critical trading platform; Fidelity Asset Management's Equity Trading Platform; Santander trading platform. (Public case links are collected in references/architecture.md.)

For an architecture that runs the EMS (Execution Management System) together on AWS Outposts, the case study points to the BLEA for FSI Hybrid securities-trading system reference architecture.

Best Practices and Key Components

Best Practices

• MUST: Separate the "order receipt & fill" (受注・約定) processing from the "order placement & execution result" (発注・出来) processing, and connect the two through an asynchronous messaging tier — this decoupling lets each layer scale independently, keeps consistency within each layer, and lets firms swap the messaging backbone to fit their needs.
• SHOULD: Place the "order placement & execution result" processing close to the EMS (Execution Management System) that routes orders to exchanges, to minimize exchange-communication latency.
• PREFER: When extremely low latency is required, disable cross-AZ communication and complete all processing within a single AZ using an AZ-level Active/Standby architecture; when the latency requirement is relaxed, the same architecture can be configured as a cross-AZ Active/Active multi-AZ deployment.
• SHOULD: Enable AWS Auto Zone Shift so that when an AZ fails, traffic is automatically shifted away from the affected AZ — it is recommended for both the Active/Standby (cross-AZ disabled) and the Active/Active (cross-AZ allowed) configurations to quickly detach a failing AZ.
• MUST: For services not directly supported by Auto Zone Shift (as of 2025/08, Amazon ECS and Amazon ElastiCache for Redis), implement custom failover using an Auto Zone Shift start-event notification delivered via Amazon EventBridge and orchestrated with AWS Step Functions and AWS Lambda.
• SHOULD: Combine reactive load-based autoscaling with scheduled scaling — e.g. predict opening-auction order volume and scale out before the market opens — because the reaction speed of load-based scaling alone is a limitation against sudden bursts.
• SHOULD: For OMS-to-back-office data linkage (positions/balances, customer master, credit info, fee/tax calculation results), use managed services — Amazon S3 as the data-exchange relay point, AWS Step Functions for workflow control, and AWS Lambda for execution — to gain scalability and reduce operational load in the overnight batch (ingest, consistency verification, refresh).
• PREFER: For mission-critical DR, adopt a multi-region configuration; use Aurora cross-region replication to avoid data loss, but note messaging-tier data needs separate loss-pattern protection.
• SHOULD: Plan the DR switchover as a deliberate, largely manual process (re-establishing exchange connectivity, verifying back-office data consistency), reserving a realistic window of several hours to about one business day and choosing timing that minimizes business impact.
• MAY: Consider AWS Outposts placed near the exchange or in a colocation center to minimize FIX-protocol communication delay to the exchange; a single Outposts is the base configuration, and multiple Outposts can be considered for higher availability at the cost of added data-consistency work.
• MUST NOT: Assume the Auto-Zone-Shift custom-failover implementation for out-of-scope services will work during an AWS control-plane outage — it depends on the AWS control plane and may not function then.

Key Components

Order Receipt & Fill (Front) Microservice

• Component Overview: Accepts orders from retail investors, institutional investors, and traders, and manages fills. Runs as a container-based microservice because its load characteristics and business-logic change frequency differ from the execution side; it can scale independently.
• Assumed AWS Services: Amazon Elastic Container Service (ECS)

Order Placement & Execution-Result (Execution) Microservice

• Component Overview: Handles order placement to and execution results from exchanges, positioned logically close to the EMS to minimize exchange-communication latency. Can be relocated onto AWS Outposts near the exchange for the lowest latency. Scales independently from the front layer.
• Assumed AWS Services: Amazon Elastic Container Service (ECS); optionally AWS Outposts

Low-Latency Messaging Backbone

• Component Overview: Asynchronous messaging tier connecting the "order receipt & fill" and "order placement & execution result" layers. Uses in-memory Redis Streams for high-speed, low-latency processing with simple operations. The component is swappable: MSK for long retention / many consumer groups, or SQS for simple queueing where ordering is less important.
• Assumed AWS Services: Amazon ElastiCache for Redis (Redis Streams); alternatives Amazon MSK, Amazon SQS

Primary Relational Database

• Component Overview: Main relational database for OMS data. Supports cross-AZ replication for data durability during an AZ failure, and cross-region replication for DR.
• Assumed AWS Services: Amazon Aurora

Market Data Distribution

• Component Overview: Receives market information (price movements, quotes) from information vendors and distributes it to investor clients in real time over WebSocket.
• Assumed AWS Services: WebSocket-based real-time distribution (delivered from the OMS application tier)

Back-Office Data Linkage / Overnight Batch

• Component Overview: Daily linkage with the securities back-office system to refresh OMS data with confirmed customer positions/balances, customer master, credit information, and fee/tax results. Uses S3 as the data-exchange relay point, Step Functions for workflow control, and Lambda for execution (ingest, consistency verification, refresh).
• Assumed AWS Services: Amazon S3, AWS Step Functions, AWS Lambda

AZ Failover Orchestration

• Component Overview: Provides automatic AZ failover. AWS Auto Zone Shift evacuates traffic from a failed AZ. For services not directly supported (Amazon ECS, ElastiCache for Redis, as of 2025/08), a custom failover is driven by an Auto Zone Shift start event via EventBridge, orchestrated by Step Functions and Lambda.
• Assumed AWS Services: AWS Auto Zone Shift, Amazon EventBridge, AWS Step Functions, AWS Lambda

Exchange Connectivity

• Component Overview: Network connection point to exchanges, assumed to be located in the on-premises environment; communicates with exchanges via the FIX protocol. Placing the execution side on AWS Outposts near the exchange minimizes this network delay.
• Assumed AWS Services: On-premises network connection point; AWS Outposts (for proximity)

FISC Compliance Summary

There is no dedicated FISC mapping file for this case study, and the source case-study document does not contain a FISC safety-standards mapping or explicit FISC control references. Accordingly, no FISC/regulatory control mapping is reproduced here (none is fabricated).

The regulatory-relevant points that are present in the source are business/operational resilience characteristics rather than FISC control mappings: securities trading is treated as important social infrastructure with increasingly stringent availability requirements; the design therefore emphasizes AZ-fault tolerance (Auto Zone Shift plus custom failover), data durability (Aurora cross-AZ replication and synchronous writes to multiple ElastiCache for Redis clusters), and mission-critical DR via multi-region configuration with a deliberate, largely manual switchover window of several hours to about one business day.

Reference Architecture

The full architecture description — base architecture, the latency-minimized multi-AZ (Active/Standby, cross-AZ disabled) configuration, the AWS Outposts configuration, the DR configuration, and the FAQ (latency figures, messaging choice, data durability, burst handling) — is preserved in references/architecture.md, along with the architecture diagrams and the public reference links.

Architecture diagrams (in assets/images/):

• Reference architecture: assets/images/reference-architecture.png
• Latency-minimized multi-AZ configuration: assets/images/multiaz-architecture.png
• AWS Outposts configuration: assets/images/outposts-architecture.png

CDK Sample Overview

No CDK sample is provided for this case study.