Protocol Engineer (Contract, Brazil)

**About Nexus** Nexus is the engine for verifiable finance — a blockchain designed to natively embed the world’s financial system into one compounding system. Built to support every major financial market on a single global exchange, Nexus unifies infrastructure that has historically been fragmented across chains and intermediaries. Headquartered in San Francisco with a growing presence in Buenos Aires, Nexus is proud to be a cross\-continental team of engineers, cryptographers, and market builders. We’re investing deeply in the Latin American ecosystem — and always looking for world\-class talent to join us. Nexus is backed by leading investors, including Pantera, Lightspeed, Dragonfly, Faction, Blockchain Builders Fund, Alliance, and SVA, and works with more than 100 partners across the global finance and blockchain stack. **Location:** Remote (Brazil applicants ONLY) **Type:** Contract **Duration:** 12 months with potential for extension The Role We’re hiring Protocol Engineers in Latin America to work at the core of Nexus’s Layer 1 execution runtime — building and evolving the systems that define how the protocol executes transactions, processes orders, and computes state transitions. This is not a typical backend role. You’ll work on performance\-critical protocol execution paths where microseconds matter, designing and implementing systems that may be enshrined directly into the Nexus protocol. Your work will influence the execution model, runtime abstractions, and performance guarantees of a next\-generation Layer 1 blockchain and high\-throughput DEX engine. Whether you’re a strong mid\-level engineer looking to grow into protocol ownership or a senior/principal engineer eager to architect execution\-layer systems, this role offers the opportunity to shape how the protocol itself behaves under load. You’ll collaborate closely with protocol, cryptography, and product teams in San Francisco while contributing remotely from Mexico or Argentina. What You’ll Do * Design and implement protocol\-level execution systems in Rust, C\+\+, or Go. * Build and evolve the runtime responsible for transaction execution, order processing, and state transitions. * Optimize concurrency, scheduling, memory layout, and I/O for deterministic, high\-throughput execution. * Define and implement execution abstractions that may be enshrined at the protocol layer. * Work with cryptography and consensus engineers to ensure safety, correctness, and composability. * Diagnose and resolve performance and correctness issues using profiling, tracing, and benchmarking. * Help establish standards for protocol correctness, reliability, and execution guarantees. * For senior/principal engineers: lead execution of architecture decisions and mentor engineers working on protocol systems. What We’re Looking For * Strong experience with Rust, C\+\+, Go, or other systems programming languages. * Experience working on protocols, runtimes, execution layers, or consensus\-adjacent systems. * Deep understanding of distributed systems, concurrency, and low\-latency execution. * Ability to reason about correctness, determinism, and invariants at the protocol level. * Practical experience optimizing performance\-critical systems. * Comfort operating in environments where correctness and performance are equally critical. * Excellent communication skills in Business English (spoken and written). Bonus Points * Experience with blockchain protocol design, execution engines, or transaction ordering. * Familiarity with lock\-free concurrency, cache\-aware data structures, or zero\-copy designs. * Background in formal methods, static analysis, or correctness\-focused engineering. * Contributions to open\-source protocol or systems\-level projects. Why Join Us * Help define the execution semantics of a new Layer 1 blockchain. * Work on protocol systems where your decisions have network\-wide impact. * Grow into ownership of protocol\-critical execution components. * Shape primitives intended to last — performant, correct, and foundational. * Join a culture that values deep technical rigor and long\-term thinking.