Senior Backend JavaScript Developer

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

US, REMOTE (Hybrid)

Description

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

Responsibilities

• 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.

Requirements

• 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 WebSockets.
• 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.