Systems Engineer

About Nexus Nexus is building the foundation for verifiable finance, an economic system where every transaction, order, and settlement can be proven on-chain with cryptographic assurance. To do this we’re developing a DEX Layer 1 blockchain purpose-built for the AI economy, powered by idle compute from millions of people around the world, and verified with zero-knowledge proofs. This is finance rebuilt for the future: verifiable, scalable, and open to all. Nexus has raised $25M in Series A funding from Lightspeed, Pantera, Dragonfly, SV Angel, and more. Location: Remote (Argentina) Type: Contract Duration: 12 months with potential for extension The Role We’re hiring Systems Engineers in Latin America to work at the core of Nexus’s execution stack — contributing to the runtime behind our Layer 1 protocol and the high-performance engine that powers decentralized trading. This is not a typical backend role. You’ll design, implement, and optimize all layers of the Nexus protocol stack — including consensus, execution, and API/RPC servers — while helping define new financial and trading primitives on the Nexus L1. You’ll work on performance-critical systems where microseconds matter, building execution paths that may evolve into core protocol primitives. Whether you’re a strong mid-level engineer ready to grow into system ownership or a senior/principal engineer eager to architect high-throughput distributed systems, this role offers the opportunity to build software that runs at the heart of a global execution layer. You’ll collaborate closely with protocol, cryptography, and product teams in San Francisco while contributing remotely from Argentina. What You’ll Do Design, implement, and optimize high-performance components in Rust, C++, or Go for Nexus’s DEX engine and protocol runtime. Design, implement, and optimize all layers of the Nexus protocol stack, including consensus, execution, and API/RPC servers. Build low-latency pipelines for order execution, event propagation, and state updates. Design and implement financial and trading primitives on the Nexus L. Optimize concurrency, scheduling, memory layout, and I/O paths for determinism and throughput. Contribute to the evolution of execution abstractions that may be enshrined at the protocol layer. Work with protocol engineers to ensure safety, composability, and consensus compatibility. Investigate and resolve performance bottlenecks using profiling, tracing, and benchmarking techniques. Help define standards for reliability, correctness, and high-assurance distributed execution. For senior/principal candidates: drive system design decisions, shape execution architecture, and mentor others in performance engineering. What We’re Looking For Very strong systems engineering ability: writing modular, maintainable code within a complex codebase where correctness and performance are critical. Experience with Rust (or C++/Go with strong performance focus). Understanding of high-performance or distributed systems (e.g., low-latency engines, runtimes, databases, OS-level concurrency). Ability to think in terms of execution flows, concurrency models, resource lifecycles, and system invariants. Interest in performance optimization and low-level profiling (CPU, memory, synchronization overhead). Strong first-principles thinker with excellent problem-solving skills, attention to detail, and communication ability. Competitive programming experience (e.g., IOI, ICPC) or similar level of programming ability is a plus. Excellent communication skills in business English (spoken and written). Bonus Points For Experience building matching engines, databases, compilers, blockchain runtimes, or HPC systems. Familiarity with lock-free concurrency, zero-copy data structures, or cache-aware design. Exposure to protocol engineering, consensus systems, or transaction ordering. Background in correctness-focused engineering (e.g., formal verification, static analysis). Open-source contributions to systems-level projects. Why Join Us Build the execution backbone of a Layer 1 blockchain and next-generation DEX engine. Work on systems where your optimizations translate directly into global performance gains. Grow from mid-level contributor to system owner — or drive execution architecture as a senior/principal. Shape primitives designed to last — correct, performant, and potentially enshrined at the protocol level. Join a high-performance engineering culture ambition and deep technical work are expected. #J-18808-Ljbffr