Senior Software Engineer (C++) Remote (Spain) High-Performance Trading Systems Up to £180k + bonus + equity We’re hiring a Senior C++ Engineer to work on the systems that sit at the heart of a integral trading platform. This is a backend, systems-focused role centred around performance-critical engineering — building the infrastructure that enables fast, reliable, and secure execution at scale. The Role You’ll be working on the core framework and performance-critical components that underpin the trading engine. Your responsibilities will include: * Designing and building low-level systems that support high-frequency transaction processing * Developing robust, reusable components used across the trading platform * Engineering for low latency, high throughput, and system resilience * Working on concurrent and distributed systems operating under real production load * Identifying and resolving bottlenecks across CPU, memory, and network layers * Writing efficient, maintainable, and well-tested C++ code * Partnering with cross-functional teams to deliver scalable technical solutions What They’re Looking For * Strong experience building production systems in C++ * Background working on high-performance, low-latency, or high-throughput systems * Solid understanding of multithreading, concurrency, and memory management * Experience working in Linux-based environments * Familiarity with distributed systems or large-scale architectures * Experience with performance tuning and profiling at system level * Exposure to other languages (e.g. Python, Java, SQL) is beneficial * Interest in trading systems, financial infrastructure, or market mechanics is a plus * Comfortable operating in a fast-paced, delivery-focused environment Why This Role * Strong comp (including bonus & equity) * Opportunity to solve complex, performance-driven engineering problems * High ownership culture * Remote-first setup with a globally distributed team