Rethinking Cardinality & Secrets to Reliable Software

We open 2027 with two talks that look at modern engineering from very different angles. Joel Verezhak from Grafana Labs revisits cardinality in observability and asks whether years of warning developers away from it has cost us valuable insight. Dorota Parad shares the often overlooked foundations of reliable software, the parts that have nothing to do with your tech stack. A solid mix to start the year, plus the usual networking apero.

Here's what's planned for the evening:
17:30 - 18:00 - Arrival and first drinks
18:00 - 18:45 - What's So Bad About Cardinality Anyway? Rethinking Metrics in the Modern Observability Ecosystem by Joel Verezhak
18:45 - 19:30 - Slow and Boring? Secrets to Building Reliable Software by Dorota Parad
19:30 - 20:30 - Networking, Open Space & More drinks*

What's So Bad About Cardinality Anyway? Rethinking Metrics in the Modern Observability Ecosystem
For years, observability teams have warned developers to avoid high-cardinality metrics. We treat cardinality like a natural disaster rather than something we can design for. But what if the fear comes not from inherent limits, but from historical constraints baked into early metrics systems?
This talk reexamines cardinality through a historical and architectural perspective. We'll explore how the original Prometheus design created cultural habits that persist, and how modern systems change the equation. With remote-write storage, Parquet-based engines, OTLP-native pipelines, exemplars, and alternative backends like ClickHouse, high-cardinality data is no longer something we must avoid, it's something we can use intentionally.
Rather than asking how to stop cardinality, we'll ask what insights we've been missing by fearing it, and how to design observability platforms that support flexible dimensionality without compromising reliability or cost.
Key takeaways: why cardinality fear is cultural and historical, not fundamental; how early metrics architectures shaped today's constraints; modern tools that enable safe high-cardinality analytics (Parquet, ClickHouse, exemplars); when to choose metrics vs traces vs logs vs column stores; and practical patterns for platform teams that enable, rather than restrict, engineers.

Joel Verezhak
Observability Architect @ Grafana Labs
Joel is an observability architect at Grafana Labs. His job is to make sure that telemetry data keeps flowing, whatever happens.

Slow and Boring? Secrets to Building Reliable Software
When thinking about building reliable software, we mostly focus on technology. While our tech stack, architecture, and good practices all matter, they are not what determines the reliability of our software.
Drawing from her experience of delivering software with strict SLAs, Dorota talks about often overlooked foundations for creating software that doesn't flake. Spoiler: it's not about technology at all.
She covers aspects that can help or hinder the reliability of your software, including measuring performance and rewarding people, team composition and structure, ways to organize the work itself, balancing the boring with the exciting, and common leadership mistakes that undermine your operations.

Dorota Parad
Founder and CEO @ Authress
Dorota is the CEO at Authress. With two decades of experience in different software roles, from coding, testing, UX, through product and engineering management, to business operations, she brings a down-to-earth perspective to complex topics people prefer to avoid.

Many thanks to our sponsors:

• Catering Sponsor: DevOpsDays Zürich https://www.devopsdays.ch/
• Location Sponsor: Digicomp https://www.digicomp.ch/

* contact us min. 3 days prior to the event if you prefer a vegan option.