Senior Node Developer - C/Go

Since 2016, Wallarm has been on a mission to secure the internet's critical infrastructure: APIs. Today, we are the trusted choice for over 200 of the world's most innovative companies, from high-growth startups to Fortune 500 and Nasdaq leaders. Our unified platform provides full-lifecycle API security — helping teams discover their attack surface, protect against modern threats, and respond to incidents in real-time. As a graduate of Y Combinator and fueled by a recent $55M Series C, we are scaling our global, remote-first team of 150+ innovators to solve the next generation of security challenges.

About this opportunity:

This isn't just another development role. We are hiring for the Node team, the group responsible for building and maintaining the core high-performance engine of the entire Wallarm product. This is the central component that processes billions of API requests, performing the deep analysis and security filtering that our customers rely on.

In this role, you will be solving some of our most complex technical challenges. You'll be working at the intersection of low-level systems programming (C and Go), high-throughput networking, and cutting-edge application security. This component is the "brain" of our solution, and its performance and reliability are paramount.

If you are driven by the challenge of optimizing systems for extreme performance, securing complex applications at scale, and owning a mission-critical piece of technology, this is the opportunity for you.

What you’ll do:

• Design, build, and maintain the high-performance C and Golang components that form the core of our API security analysis and filtering engine.

• Conduct deep performance analysis and optimization. You'll be the one diving in when memory usage (RSS) spikes or pprof isn't telling the whole story, using tools like gdb, Valgrind, and perf to find and fix complex bottlenecks.

• Develop and manage critical integrations, including modules for Nginx and Envoy, and navigate the complexities of C-to-Go bindings (CGO), managing garbage collection, memory lifetimes, and pinning.

• Own the full lifecycle of the filter node, from package management (installers, deployments) to troubleshooting in production Linux environments (including systemd).

• Perform low-level network troubleshooting and analysis, using tools like Wireshark, libpcap, and gopacket to inspect traffic and diagnose protocol-level issues.

• Collaborate on cloud-native deployments, contributing to Kubernetes (K8s) and Helm configurations to ensure our node runs efficiently at scale.

We’re looking for a candidate with:

• 5+ years of experience as a software engineer.

• Professional experience in C or Golang. Proficiency in C is highly preferred, but the most important requirement is a strong command of one and a willingness to master both.

• Advanced Linux proficiency. You are comfortable troubleshooting services (systemd), analyzing builds, and using profiling/debugging tools like gdb, Valgrind, and heaptrack.

• Deep understanding of systems programming. You have a firm grasp of multithreading, asynchronous programming, synchronization primitives, and the common pitfalls associated with them.

• Strong networking fundamentals. You must have a solid understanding of network protocols, especially TCP (streams, packet loss), and deep knowledge of HTTP/HTTP2.

• Familiarity with web server architecture and foundational concepts in information security.

Nice to have:

• Cloud-Native Expertise: Hands-on experience with Kubernetes, Istio, or writing your own K8s/Helm deployments.

• Nginx Mastery: Deep internal knowledge of Nginx and (especially) experience writing Nginx modules.

• Advanced Networking: Practical experience with network analysis tools and libraries like gopacket (Go) or libpcap/raw sockets (C).

• CGO Experience: Proven experience using C libraries from Go and navigating the associated challenges (GC, memory pinning, performance).

• Related Domains: Previous work in anti-fraud systems, load balancer customization, or practical application security (web or binary).

• Specific Tech Knowledge: Familiarity with gRPC, parser construction (e.g., flex/bison), or other languages like Python, Ruby, Java, Rust, or JS.

What we offer:

• Completely remote work and flexible working hours

• Competitive salary and bonuses

• Paid days off

• Medical insurance

• Working equipment

• Professional development and career growth