Observability Summit North America 2026

Reddit processes over 25 billion tracing events per hour across thousands of services. In this talk, we share how we scaled our OpenTelemetry-based distributed tracing platform by 67% in one year—and what broke along the way.

We'll cover our architecture: OpenTelemetry instrumentation across Python, Go, and JavaScript baseplate libraries feeding into Kafka pipelines and ClickHouse storage. You'll learn how we handled an incident that spiked ingestion to well over 10 million spans per second, the sampling strategies we developed to balance cost with debuggability, and why instrumenting three language runtimes simultaneously is harder than it sounds.

Key takeaways:
- Practical patterns for multi-language OTel instrumentation at scale
- Remote sampling strategies that adapt to traffic patterns
- ClickHouse schema design for sub-second trace queries
- Building adoption through cross-functional partnerships, not mandates

Whether you're starting your tracing journey or scaling an existing platform, this talk provides battle-tested lessons from running distributed tracing infrastructure serving one of the world's largest online communities.