Lead C# Developer - Core Trading Technology

Susquehanna International; Sydney; Hybrid; AUD 180,000 - 240,000; Full time

Job summary

Susquehanna International in Sydney is seeking a C# Lead Developer to drive the design, development, and delivery of core trading applications in a fast-paced front-office environment.

You will mentor a team of developers, collaborate with traders, quants and tech stakeholders, and remain hands-on in critical areas to ensure performance and reliability.

Qualifications

• Bachelor’s degree or higher in a technical discipline.
• 10+ years of C# experience across server-side and client-side development.
• Proven leadership or management experience of a dev team.
• Deep knowledge of software design, OOP, profiling and performance tuning.
• Experience delivering complex, business-critical systems through full SDLC, Agile preferred.
• Strong interpersonal and communication skills for traders, quants and tech teams.
• Ability to meet deadlines and work under pressure in a fast-paced trading environment.
• Attention to detail and accuracy.

Responsibilities

• Lead and manage a team of developers, setting priorities and blockers.
• Mentor junior/mid-level developers through code reviews and pairing.
• Contribute to hiring, onboarding and performance feedback.
• Set technical direction and architecture standards with performance and resilience in mind.
• Uphold engineering best practices, testing, profiling and CI/CD.
• Stay hands-on when tackling complex multi-threading and critical code issues.
• Partner with traders, quants and senior tech stakeholders to align delivery with requirements.
• Drive continuous improvement through automation and process changes.

Skills

Leadership

Mentoring

Multi-threading

Communication

Agile

Team collaboration

Decision making

Education

Bachelor’s degree in technical discipline

Tools

WPF

.NET Core on Linux

Tibco RV

CI/CD practices

Job description

Overview

As a C# Lead Developer in the Core Trading Technology team, you will lead the analysis, design and development of applications in a Front Office trading environment. The software spans server-side systems and user interfaces. You will manage and mentor a team of developers while remaining hands‑on in the technical direction of the platform. You will work closely with traders, quantitative researchers and technology teams to turn requirements into reliable, high-performing software covering almost all aspects of the trading environment.

The Sydney Core Trading Technology team owns a rich mix of proprietary software focused on highly available applications, including trading analysis tools, market and static data feeds, trade monitoring and real-time messaging, all used to support trading decisions.

Responsibilities

Leadership and people

• Lead and manage a team of developers, setting priorities, allocating work and removing blockers.
• Mentor and coach junior and mid-level developers through code reviews, pairing, and career development.
• Contribute to hiring, onboarding, performance feedback and succession planning.
• Foster a high-performing, collaborative and accountable engineering culture.

Technical delivery

• Own the analysis, design and development of business-critical applications, from requirements gathering through to production release and support.
• Set technical direction and architecture standards, and make sound design trade-offs across performance, resilience and maintainability.
• Establish and uphold engineering best practice, including code quality, testing, profiling, CI/CD and operational readiness.
• Remain hands‑on where it matters: prototyping, tackling complex multi-threading and performance problems, and reviewing critical code.

Stakeholders and improvement

• Partner with traders, quants and senior technology stakeholders to understand needs, set expectations and communicate delivery status and risks.
• Drive continuous improvement of the team’s capability and applications through technology, automation and process.
• Stay curious about new technologies and assess where they can add value to the trading platform.

What we’re looking for

Essential qualifications and experience

• Bachelor’s degree (or higher) in a technical or related discipline.
• 10+ years of C# experience across server-side systems (with strong multi-threading) and client-side development.
• Proven experience leading or managing a development team, including mentoring junior engineers and developing talent.
• Deep knowledge of software design, object-oriented principles, profiling and performance tuning, multi-threading, and UI development on both client and server sides.
• Track record of delivering complex, business-critical systems through the full software development life cycle, ideally in an Agile environment.
• Strong interpersonal and communication skills, with the ability to engage traders, quantitative analysts, developers and senior management.
• Ability to meet deadlines and make sound decisions under pressure in a fast-paced environment.
• Excellent attention to detail and accuracy.

Advantageous

• WPF experience.
• Experience running and deploying .NET Core applications on Linux.
• Experience with real-time applications, especially Tibco RV.
• Experience in a front‑office trading or financial markets environment.

What You’ll Bring to the Team

• A balance of hands‑on technical credibility and people leadership.
• The ability to build trust with both engineers and business stakeholders.
• A commitment to raising the bar for the team’s skills, tooling and delivery practices.

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