Senior Backend Engineer – Critical High-Performance Systems

Description

Job Summary: We are seeking a Senior Backend Engineer for a strategic project involving high-performance critical systems within the financial sector, focused on optimization and real distributed architecture. Key Highlights: 1. Participation in the evolution of high-efficiency critical platforms. 2. Advanced technical environment with a focus on quality engineering. 3. Opportunity to work on architectures where performance is critical. Senior Backend Engineer – Critical High-Performance Systems Madrid (northwest area) \| Hybrid model (3 days onsite) * Full-time \| Immediate start \| Strategic project An international technology firm specializing in digital transformation for large corporations is seeking to hire a Senior Backend Engineer for a technically demanding project within the financial sector. This is not a position oriented toward "standard development." Here, we speak about performance, concurrency, optimization, and real distributed architecture. The Challenge Participate in the evolution of critical platforms where code efficiency and system stability are paramount. You will work in high-concurrency environments requiring minimal latency and absolute robustness. Main Responsibilities Backend development with a strong focus on performance and scalability. Advanced programming in Python (core development, not data-related). Implementation and optimization of components in C\+\+ (Java is a plus). Design and integration of APIs in distributed environments. Working with in-memory databases (Redis and/or Valkey). Participation in architectures based on distributed computing grids (HTC, Condor, IBM Symphony, TIBCO DataSynapse or similar solutions). Diagnosis and resolution of complex production incidents. Application of best practices: testing, technical documentation, and code quality. Proven senior-level backend development experience. Strong structural and architectural mastery of Python. Solid hands-on experience in C\+\+ with an optimization focus. Practical knowledge of distributed systems and grid-style computing. Experience consuming and integrating APIs. Advanced English (C1 or equivalent). Residency in Spain and valid documentation. A university degree is not mandatory if professional experience is substantial and consistent. We seek an analytical, autonomous mind comfortable in technically demanding environments. Participation in a high-impact initiative within the financial sector. Advanced technical environment with a focus on quality engineering. Stable hybrid model (3 days per week onsite in Madrid’s northwest area). Intensive summer working hours. Integration into an international team with a strong technical culture. If you enjoy fine-tuning code down to the millisecond and are motivated by working on architectures where performance is not optional—but critical—this is your next challenge.