Senior Software Engineer

GCS Recruitment; Ireland; On-site; EUR 147,600 - 202,950; Full time

Job summary

GCS Recruitment is seeking a Software Engineer to join a Tier-1 investment bank in Dublin on a hybrid contract. You will work on low-latency, high-throughput distributed systems that process millions of market events per second, building in C++, Java, or Rust with emphasis on performance and reliability.

The team works closely with trading desks, profiling at the OS/network level, with NUMA awareness and kernel bypass techniques.

Qualifications

• Strong CS fundamentals: concurrency, memory management, and networking internals.
• Experience with performance-sensitive environments using C++, Java, or Rust.

Responsibilities

• Develop low-latency, high-throughput distributed systems processing market events.
• Optimize performance in execution paths, including kernel bypass and zero-copy designs.
• Ingest market data, route orders, and support risk systems at exchange speeds.
• Collaborate with quant developers and trading desks.
• Profile and tune OS/network performance around NUMA and CPU pinning.

Skills

Low-latency systems

C++/Java/Rust

Kernel bypass

Performance optimization

Concurrency

Tools

DPDK

Job description

Software Engineer - Low Latency / Distributed Systems

Tier-1 Investment Bank, Dublin (Hybrid) - Contract

Leading investment bank's Dublin technology hub is expanding its high-frequency trading infrastructure team. This is deep, hard engineering - the systems you build execute trades in microseconds, and every millisecond you shave off is measurable P&L. Not a CRUD shop, not a maintenance role.

What you'll work on

• Low-latency, high-throughput distributed systems processing millions of market events per second
• Performance-critical execution paths in C++/Java/Rust - kernel bypass, lock-free data structures, zero-copy design
• Market data ingestion, order routing, and risk systems operating at exchange speed
• Direct collaboration with quant developers and trading desks
• Profiling and tuning at the OS/network/hardware boundary - NUMA awareness, CPU pinning, kernel bypass networking (DPDK/Solarflare-style stacks)

What we're looking for

• Strong CS fundamentals - concurrency, memory management, networking internals, cache-aware design
• Production experience in C++, Java, or Rust in a genuinely performance-sensitive environment
• Exposure to FIX protocol, market data feeds, or exchange connectivity is a strong plus
• Comfortable working close to the metal - this isn't abstraction-layer engineering
• Fintech/trading background not mandatory - elite backend engineers from adjacent high-scale, low-latency domains (ad-tech real-time bidding, gaming infra, telco) will be seriously considered

Team & setup

• Small, senior engineering pod embedded within the trading technology group
• Hybrid - Dublin office, with onsite time expected around trading hours/desk collaboration
• Contract engagement, initial term with strong likelihood of extension given desk growth plans

GCS is acting as an Employment Business in relation to this vacancy.