Senior Systems Engineer, Search Core & Performance

Perplexity; Greater London; On-site; GBP 90,000 - 130,000; Full time

Job summary

Perplexity in Greater London is seeking a Senior or Expert Systems Engineer to help design and implement foundational components for our search stack, influencing architecture and performance.

You will design and build core indexing pipelines, retrieval and ranking components, and optimize for high-load environments, with emphasis on multithreading, Linux internals, and production readiness.

Qualifications

• 3+ years of hands-on experience in systems programming
• Ownership of full project lifecycle — you don't just write a fast inner loop, you care about how the system is built, deployed, operated, and scaled in production
• Knowledge of Python or other scripting languages
• Passion for writing clean, efficient, and scalable systems-level code
• Strong knowledge of algorithms and data structures, and the ability to apply them effectively
• Deep understanding of multithreading, including various approaches, challenges, and trade-offs
• Experience building high-load, distributed, and hardware-adjacent services
• Solid understanding of Linux internals (syscalls, networking stack, memory model, kernel tuning)
• Familiarity with low-level optimization techniques (memory management, cache efficiency, SIMD, profiling)

Responsibilities

• Design and build core search engine components, including indexing pipelines, retrieval algorithms, and ranking systems that operate at the scale of billions of pages
• Develop streaming and batch data processing systems for search index construction in a high-load environment
• Push the limits of hardware performance through low-level optimizations and systems-level tuning
• Tackle challenges in multithreading, concurrency, and system-level optimization

Skills

Rust

C++

C

Python

Multithreading

Tools

Linux

Kubernetes

AWS

Job description

Perplexity in Greater London is seeking a Senior or Expert Systems Engineer to help design and implement foundational components for our search stack, influencing architecture and performance.

You will design and build core indexing pipelines, retrieval and ranking components, and optimize for high-load environments, with emphasis on multithreading, Linux internals, and production readiness.