Lead/Senior Site Reliability Engineer, Zalo

At Zalo, we define SRE as what happens when a Software Engineer is tasked with solving operational and infrastructure challenges.

The Site Reliability Engineer (SRE) role requires a blend of low-level system engineering skills and a solid SRE mindset. You will leverage software engineering principles and code to build automation platforms, optimize disk/network I/O, and maintain high-scale distributed systems with high availability and ultra-low latency at millions of QPS.

What you will do

Internal Platform & Systems Engineering:

• Design and develop deep Observability systems (high-cardinality metrics, distributed tracing, large-scale logging) and Automation toolkits (Control Planes, Custom Kubernetes Operators, IaC) to drive Toil Elimination;
• Research, design, and optimize low-level system performance (Disk I/O, Network Stack, Linux Kernel Tuning) for large-scale distributed services.

Production Operations & Incident Response:

• Take ownership of the Availability, Latency, and Scalability of production services using SLOs/SLIs and Error Budgets;
• Foster a resilience for failure mindset to lead incident response for complex production issues, conduct Root Cause Analysis (RCA), and facilitate blameless postmortems to prevent recurrence.

What you will need

• 3+ years of Software Engineering experience working directly with low-level system components such as Disk I/O, Network Stack, Memory Management, etc., using systems programming languages (C++, Go, Java, or Rust);
• Distributed Systems: Strong understanding of consensus algorithms (Raft, Paxos), replication topologies, data partitioning (sharding / consistent hashing), CAP theorem, and consistency models (eventual vs. strong consistency);
• Linux Kernel: Deep understanding of Linux kernel internals (Virtual Memory, Page Cache, I/O schedulers, System calls, Process/Thread management);
• Networking: Proficient in TCP/IP stack, socket programming, HTTP/gRPC, load balancing, and network latency optimization at the Transport/Application layers;
• Observability: In-depth knowledge of observability architecture and tools (Prometheus, Grafana, OpenTelemetry, Jaeger), handling high-cardinality metrics and large-scale logging/tracing;
• SRE Mindset: Operations as Code mindset, reliability management via metrics (SLO/SLI, Error Budget), toil elimination, and automated safety guardrails (Progressive Rollout, Zero Touch Prod).

Nice to have:

• Strong Algorithmic & Data Structure Thinking: Proven ability to solve complex data structure and algorithmic optimization problems in distributed systems;
• Profiling & Diagnostic Tools: Proficiency with kernel-level diagnostic and profiling tools such as eBPF, perf, bcc-tools, and sysctl;
• Container & Orchestration: Hands-on experience with Docker, Kubernetes (writing Custom Kubernetes Operators), and Infrastructure-as-Code (Terraform/Ansible).