Senior Backend Engineer (Proxy & Infra)
Massive is an infrastructure company powering data-driven innovation at scale. We operate a global proxy network, build managed APIs for scraping, and develop AI-powered automation tools for large-scale data collection and processing.
Our Monetization SDK is a cross-platform development kit that enables app developers to offer users an alternative payment method, opting in to share small amounts of unused computing resources instead of paying with money or viewing ads. The SDK powers millions of users worldwide across desktop, mobile, and smart TV platforms.
Responsibilities
- Build, evolve, and operate the Go services that power Massive's global network.
- Diagnose and resolve performance issues across the full stack: application code, Go runtime, kernel, etc.
- Design and implement new functionality on the proxy backend with a focus on reliability and predictable performance under load.
- Define and own key reliability and performance metrics, and build the observability needed to track them.
- Contribute to capacity planning, deployment strategy, and on-call practices for the proxy fleet.
- Collaborate closely with cross-functional teams (SDK, backend, data, product) to improve system performance and reliability end-to-end.
Requirements
- 7+ years of experience with systems programming and network programming.
- 3+ years of Go, including building and operating high-concurrency services in production (tens of thousands of concurrent connections or more).
- Active user of Agentic coding tools.
- Strong working knowledge of Linux: process model, syscalls, networking stack, and performance fundamentals.
- Solid understanding of IP, TCP, and UDP protocols, including how they behave under load.
- Comfortable profiling, tracing, and debugging Go services in production (pprof, runtime metrics, goroutine and heap analysis).
- Strong communication skills and ability to take ownership.
- Self-directed and comfortable working in a fast-paced startup environment.
Bonus Points
- Hands-on Linux kernel and network performance tuning (sysctl, NIC ring buffers, IRQ affinity, NUMA, BBR, NAPI).
- Familiarity with high-throughput NICs and offload features (Mellanox/Intel, RSS, GRO/GSO, XDP/eBPF).
- Experience operating WebSocket-based services at scale.
- Experience with observability stacks (OpenTelemetry, Prometheus/VictoriaMetrics, ClickHouse).
- AWS experience (Lambda, Route 53, IAM, EC2 fleets).
- Experience with zero-downtime deployments for stateful or long-lived connection services.
- Production on-call experience and incident response practice.
- Command of C, C++, or Rust for systems-level work.