Senior Engineer, Software

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior Engineer, Software based in Spain. As a Senior Software Engineer, you will help shape and scale a high-performance search platform that powers critical business decisions through AI-driven market intelligence. You will design and optimize distributed systems capable of processing billions of documents and hundreds of queries per second with millisecond-level latency. Working in a collaborative, technically ambitious environment, you will drive platform modernization, improve system reliability, and establish engineering best practices. You will tackle complex challenges across infrastructure, data processing, and application performance while balancing scalability, cost, and efficiency. Your expertise will directly influence how users discover valuable insights and interact with large-scale information systems. This is an opportunity to take ownership of a mission-critical platform, mentor fellow engineers, and contribute to the next generation of intelligent search technology. Accountabilities:
- Architect, build, and optimize distributed systems capable of managing billions of documents and supporting high query volumes with consistently low latency.
- Lead the evolution of the search platform by migrating legacy systems to modern architectures while maintaining service continuity and improving performance.
- Establish robust engineering practices, including comprehensive monitoring, automated testing, deployment automation, and proactive incident prevention.
- Profile, diagnose, and resolve performance bottlenecks across infrastructure, databases, data pipelines, and application layers.
- Design and improve data processing architectures that support real-time workloads, efficient information retrieval, and reliable data access.
- Strengthen system observability through effective monitoring, alerting, and reliability metrics to identify and address potential issues before they affect customers.

- Contribute to the development of advanced search capabilities, including hybrid lexical and vector search approaches.
- Collaborate with engineers across the team, share technical expertise, and promote a culture of continuous improvement, operational excellence, and knowledge sharing.
- Drive measurable improvements in platform scalability, latency, reliability, and infrastructure efficiency throughout the first year and beyond.

Requirements:
- At least five years of experience building, deploying, and operating distributed systems in production environments.
- Proven experience with large-scale data platforms, high-throughput systems, or infrastructure supporting demanding workloads.
- Strong understanding of distributed systems fundamentals, including sharding, replication, consistency models, and partition tolerance.
- Demonstrated ability to analyze and optimize performance, identify bottlenecks, and implement effective solutions across the technology stack.
- Experience designing data pipelines, real-time processing systems, or database internals and architectures.
- Proficiency in building observable, reliable systems with comprehensive monitoring, alerting, and diagnostic capabilities.
- Strong problem-solving skills, sound architectural judgment, and the ability to take ownership of complex technical challenges.
- Excellent communication and collaboration skills, with a willingness to share knowledge, support colleagues, and contribute to engineering excellence.
- Familiarity with search platforms such as Vespa, Elasticsearch, or Solr, or experience working with comparable large-scale data systems, is a plus.
- Experience with Kubernetes, Custom Resource Definitions (CRDs), and infrastructure as code is advantageous.