Software Engineer, Trading Systems

Posley; Hong Kong; On-site; HKD 600,000 - 800,000; Full time

Job summary

Posley is a quantitative investment firm focused on opportunities across traditional and alternative markets. We study how price, funding, liquidity, market structure and execution interact across markets, building in-house systems used for live trading.

We are looking for a strong software engineer to build and improve our trading and execution infrastructure, touching exchange connectivity, order management, monitoring and production systems with emphasis on correctness and edge cases.

Qualifications

• Strong software engineering fundamentals.

Responsibilities

• Develop exchange connectivity through WebSocket / REST APIs.
• Improve order, position and account state management.
• Handle execution edge cases, failures, retries and reconciliation.
• Build monitoring and safeguards for live trading systems.
• Improve latency, reliability and operational resilience.
• Investigate discrepancies in positions, balances, fills, fees and P&L.
• Support deployment, cloud infrastructure and DevOps where needed.
• Work directly with quantitative researchers to bring strategies into production.

Skills

Software engineering

Distributed systems

Asynchronous design

Ownership

Trading interest

AI-assisted coding

Tools

WebSocket/REST APIs

Python

TypeScript/Node.js

Redis

Time-series DB

Cloud/DevOps

Job description

Posley is a quantitative investment firm focused on opportunities across traditional and alternative markets.

We study how price, funding, liquidity, market structure and execution interact across markets, and build systematic trading strategies around those opportunities.

We combine the discipline of a licensed investment environment with the speed and ownership of a startup. Our core research, trading and technology capabilities are built in-house, so engineers work closely with researchers and traders and see their systems running in live markets.

The Role

We are looking for a strong software engineer to help build and improve our trading and execution infrastructure.

This is not a pure DevOps role and not a traditional backend role. You will work on systems that directly interact with live markets — including execution engines, exchange connectivity, position and order management, monitoring, reconciliation and production infrastructure.

You should be someone who cares about correctness, edge cases and details, while having enough trading intuition to understand why those details matter.

What You Will Work On

• Develop exchange connectivity through WebSocket / REST APIs


• Improve order, position and account state management


• Handle execution edge cases, failures, retries and reconciliation


• Build monitoring and safeguards for live trading systems


• Improve latency, reliability and operational resilience


• Investigate discrepancies in positions, balances, fills, fees and P&L


• Support deployment, cloud infrastructure and DevOps where needed


• Work directly with quantitative researchers to bring strategies into production

Because we are a startup, the scope will evolve. If something important sits between research, trading and infrastructure, you may end up owning it.

What We Are Looking For

• Strong software engineering fundamentals


• Experience building reliable backend or distributed systems


• Strong attention to detail and a high standard for correctness


• Able to reason about asynchronous systems, state and failure scenarios


• Comfortable taking ownership without needing detailed instructions


• Genuine interest in trading, markets or quantitative systems


• Able to use AI coding agents effectively while critically reviewing and validating production-critical code

You do not need to be a quantitative researcher, but you should have enough numerical and market intuition to understand concepts such as:

• orders, fills and positions


• bid / ask and liquidity


• exposure and P&L


• fees and funding


• latency and execution quality


• basic risk controls

Our systems primarily use:

• Python for trading, execution, research and analytics


• TypeScript / Node.js across selected infrastructure and internal systems


• Redis and messaging / streaming infrastructure


• Time-series databases and monitoring systems


• APIs across centralized and decentralized trading venues

Experience with every technology above is not required. Strong engineering ability matters more than matching the stack exactly.

Nice to Have

• Experience with trading systems, exchanges or market data


• Low-latency or high-throughput systems


• Experience with reconciliation or financial systems


• Understanding of market microstructure


• Personal interest in systematic or algorithmic trading

Why Posley

You will not be maintaining one small component inside a large engineering organisation.

You will have the opportunity to:

• work within a licensed quantitative investment environment


• build systems used directly in live trading


• gain exposure to both traditional and virtual asset markets


• own meaningful pieces of production infrastructure


• work closely with traders and quantitative researchers


• see the impact of your engineering decisions quickly


• solve problems across software, markets and infrastructure

We value people who are curious, rigorous, hands-on and serious about getting the details right.

If you enjoy building systems where small engineering details can have real financial consequences, we would like to hear from you.