Senior Backend JavaScript Developer

R&D & Technical Senior Backend JavaScript Developer======================================

US, REMOTE (Hybrid)

We’re looking for exceptional and experienced Backend JavaScript Developers to join our Network team. This team builds and operates core backend services that power the company’s networking infrastructure - high-performance, highly reliable systems with deep focus on networking, security, and scale.

In this role, you will take end-to-end ownership of services and features in production, working on challenging problems around network traffic, protocols, performance, and reliability.

Tech Stack:

Node.js, JavaScript, MongoDB, Redis, Kubernetes, AWS

• End-to-end feature development, from design and implementation to production rollout and ongoing improvements.
• Build and maintain high-scale backend services with strong emphasis on performance, reliability, and security.
• Participate in system design and architecture planning to ensure scalable and maintainable solutions.
• Work on networking-related challenges such as traffic flows, proxy behavior, request/response handling, and protocol-level edge cases.
• Investigate and troubleshoot complex networking issues using tools such as Wireshark (and similar packet inspection/debugging tools).
• Write high-quality, maintainable code with appropriate test coverage; participate actively in code reviews.
• Collaborate closely with engineers and stakeholders to deliver impactful solutions.
• Continuously learn and apply best practices in backend engineering and networking.

• 5+ years of hands-on software engineering experience, including 2+ years focused on backend JavaScript / Node.js development.
• Very good understanding of how the Node.js event loop works, including practical knowledge of the platform’s strengths and limitations (I/O vs CPU-bound workloads, async patterns, blocking pitfalls, memory/GC considerations).
• Proven experience building and operating production backend services.
• Strong understanding of network protocols and security, including: TCP/IP/UDP, DNS, HTTP1/2/3, TLS and Web Sockets.
• Experience with databases and caching layers such as MongoDB and Redis.
• Familiarity with Kubernetes and containerized deployments.
• Proficient in system design fundamentals: APIs, scalability, performance, reliability, and fault tolerance.
• Fast learner, able to work independently and as part of a team.
• Proficiency in English, with strong written and verbal communication skills.

Nice to Have:

• Experience with AWS and SaaS environments.
• Experience debugging production networking issues (latency, packet loss, connection reuse, TLS handshakes, etc.).
• Experience with observability tooling (logs/metrics/tracing) and incident response/on-call.