Junior Systems Engineer

About Nexus

Nexus is building the AI gateway for modern companies — one platform that gives teams access to the world's leading AI models while keeping costs predictable, security under control, and workflows connected.

Companies can use Nexus to access models like GPT, Claude, Gemini, and many others through a unified platform. Our infrastructure helps organizations choose the right model for each task, manage usage and budgets, enforce access policies, and integrate AI into the tools their teams already use.

Headquartered in San Francisco with a growing presence in Latam, Nexus is a cross-continental team building the infrastructure that makes AI more accessible, efficient, and manageable at scale.

We're investing deeply in the Latin American engineering ecosystem and looking for exceptional talent to help us build the next generation of AI infrastructure.

Nexus is backed by leading investors, including Pantera, Lightspeed, Dragonfly, Faction, Blockchain Builders Fund, Alliance, and SVA.

Location: Remote
Type: Contract
Duration: 12 months with potential for extension

The Role

We're looking for talented Junior Systems Engineers in Latin America to join our engineering team and help build the high-performance infrastructure powering EOS's AI platform.

This is an opportunity for early-career engineers who enjoy solving challenging technical problems, understanding how systems work under the hood, and building efficient and reliable software.

You'll contribute to the core components of our AI gateway, working on areas such as request routing, concurrency, networking, streaming, and resource management.

You'll work alongside experienced engineers, gaining hands-on experience with Rust and systems programming while developing a strong understanding of performance, scalability, and distributed systems.

You'll collaborate closely with engineering and product teams in San Francisco while working remotely from Latin America.

What You'll Do

• Develop and maintain systems-level components powering EOS's AI gateway.

• Contribute to request routing, load balancing, and communication between different AI providers.

• Work on efficient request processing and streaming pipelines for AI model responses.

• Help implement rate limiting, usage tracking, and resource management features.

• Work with concurrency, asynchronous programming, networking, and I/O operations.

• Identify and help resolve performance bottlenecks in existing systems.

• Write efficient, reliable, and well-tested code, with a focus on performance and correctness.

• Collaborate with senior engineers to understand system architecture and implement technical solutions.

• Participate in code reviews, technical discussions, and engineering best practices.

What We're Looking For

• 1–3 years of professional software engineering experience, ideally working with systems programming or backend development.

• Familiarity with Rust (strongly preferred), C++, Go, or similar programming languages.

• Strong computer science fundamentals, including data structures, algorithms, and operating systems.

• Understanding of fundamental systems concepts such as memory management, concurrency, and asynchronous programming.

• Basic understanding of networking protocols such as TCP, HTTP, or WebSockets.

• Familiarity with performance optimization and an interest in understanding how software behaves under the hood.

• Strong problem-solving and analytical thinking skills.

• Ability to learn quickly, take ownership of assigned tasks, and work through challenging technical problems.

• Motivation to grow as a systems engineer and work on technically demanding infrastructure.

• Good communication skills in English, both spoken and written.

Bonus Points For

• Hands-on experience with Rust, C++, or Go.

• Familiarity with networking infrastructure, proxies, API gateways, or load balancers.

• Exposure to distributed systems or high-performance applications.

• Experience with profiling, benchmarking, or performance optimization.

• Familiarity with AI infrastructure, LLM integrations, or streaming APIs.

• Open-source contributions or personal projects involving systems programming.

• Competitive programming experience or participation in programming competitions such as ICPC.

Level

Junior Systems Engineer (1–3 years)

We're looking for engineers with strong technical foundations, an interest in low-level programming, and the potential to grow into highly capable systems engineers.

Why Join Us

• Build the future of enterprise AI: Engineer the performance-critical core that connects companies to the world’s leading AI models.

• Solve meaningful technical challenges: Work on low-latency routing, real-time streaming, and high-throughput systems where your optimizations are felt on every request.

• Work with emerging AI technologies: Build at the intersection of systems engineering and AI infrastructure.

• Have a direct impact: Shape the architecture of a growing platform where engineering decisions matter.

• Collaborate with an international team: Work alongside talented engineers and product builders across San Francisco and Latin America.

• Grow in a fast-moving environment: Grow into system ownership or drive architecture as a Principal.