OMS/Trading Systems Engineer (FX) at Wagglyn, London, £Contractor Rate (Outside IR35)

Role Summary

Wagglyn is seeking an experienced OMS / Trading Systems Engineer – Contractor to work with the existing engineering team on the design and implementation of the order management and execution control layer underpinning our low-latency FX trading platform.

This is a hands-on engineering role focused on building the core trading state and execution orchestration layer for a systematic FX trading platform operating across multiple brokers, venues, accounts, and execution routes.

The OMS layer acts as the canonical source of truth for trading state, execution workflow, position attribution, and operational controls across the platform.

You will work closely with the CTO and engineering team to design deterministic, production-ready systems capable of operating reliably under real market conditions.

This role is not suited to generic backend developers or UI-focused engineers.

Responsibilities

· Design and implement core OMS / EMS infrastructure supporting systematic FX trading

· Develop systems responsible for:

o Order lifecycle management

o Strategy instruction handling

o Execution control and routing

o Position attribution and reconciliation

· Contribute to the design of a deterministic, event-driven trading architecture, including:

o Command bus and event bus workflows

o Reliable state propagation across trading systems

o Replayability and deterministic recovery under failure conditions

· Help define and refine the platform’s execution control model, including:

o Strategy-level permissions and controls

o Broker account and venue routing logic

o Risk limits and kill-switch mechanisms

o Auditability of configuration and operational controls

· Implement robust handling for:

o Execution reports, fills, and partial fills

o Drop copy reconciliation

o Idempotency and duplicate order prevention

o Real-world execution edge cases and state consistency

· Work closely with the engineering team to define:

o Domain models

o Component boundaries

o Event-driven workflows between strategies, OMS components, and execution gateways

Platform Direction

The platform is evolving towards a configurable, event-driven trading model where strategies emit trading intent, while the OMS layer manages execution state, routing permissions, reconciliation, attribution, and operational controls.

The contractor will help ensure this model remains deterministic, auditable, and operationally robust under live trading conditions.

Required Experience

· Strong experience building OMS / EMS / trading systems in electronic trading environments

· Deep understanding of:

o Real-world order lifecycle and execution workflows

o FIX order flow, execution reports, and drop copy handling

o Deterministic event-driven system design

· Strong experience with:

o Idempotency and duplicate order prevention

o Position keeping and strategy-level attribution

o Reconciliation workflows and operational state consistency

· Strong backend engineering ability in:

o Rust, Java, C++, or similar low-level systems languages

· Comfortable working within:

o Existing engineering teams

o Existing production-oriented codebases

Technical Environment

Candidates should have experience with, or strong familiarity with:

· Languages: Rust, Java, C++, Python

· Protocols: FIX (4.2), execution report and drop copy workflows

· Architecture: Event-driven systems, command/event bus patterns

· Messaging: Kafka, NATS, Redpanda, Redis Streams or similar

· Data: PostgreSQL, QuestDB, or similar systems

· Infrastructure: Low latency and high-throughput trading systems

Preferred Experience

· Experience in electronic FX trading systems

· Familiarity with:

o Multi-venue execution environments

o Broker and margin account modelling

o Low latency execution infrastructure

· Experience working with:

o Rust-based trading systems

o High-throughput or low-latency environments

What Success Looks Like

In the first 2–3 months, you will:

· Help define and implement the core OMS domain and execution control model

· Improve correctness and determinism across order and execution workflows

· Deliver production-ready components supporting reliable live trading operations

· Improve operational confidence in system state, attribution, and reconciliation

Profile

· Senior hands-on contractor comfortable working on complex trading systems

· Able to:

o Design and implement robust solutions

o Challenge and refine architecture where appropriate

· Pragmatic and delivery-focused:

o Prioritises correctness, determinism, and operational robustness over unnecessary complexity

· Strong collaborator able to work effectively with:

o Backend engineers

o Low latency engineers

o Quantitative researchers

Contract Structure

· Full-time contractor

· Rolling fixed-term arrangement

· Immediate start preferred

· Outside IR35

· Strong preference for candidates who are immediately available

Important

· Applications from candidates with direct OMS / trading systems experience are strongly preferred

· This role is not suitable for generic backend developers without trading systems exposure

· No recruiter or agency approaches, please

About Wagglyn

Wagglyn is a bespoke FX consultancy mandated by a single-family office to develop and implement a systematic total return strategy in foreign exchange markets.

We are building an institutional-grade algorithmic FX trading capability, combining quantitative research and high-performance engineering.