Sergio Herrero
I'm Sergio Herrero. I write about platform engineering, SRE, development, and infrastructure.
Consulting
I help with cloud and infrastructure problems, from the most basic to the most advanced. For companies and for individual developers.
Cloud/SRE consulting
Architecture, migrations, Kubernetes, Terraform, observability, FinOps.
Audits and troubleshooting
Review of existing infrastructure, incidents, cost, security.
Mentoring and training
1:1 sessions for developers who want to learn cloud and DevOps.
Custom development
Direct implementation of code and infrastructure as code, not just advice.
Latest writing
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Provisioners in Terraform
What creation-time and destroy-time provisioners do, what happens when they fail, and why HashiCorp treats them as a last resort compared to each provider's native alternatives.
- terraform
- iac
- provisioners
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count vs for_each in Terraform
Differences between the count and for_each meta-arguments, when to use each one, and the problem with count on indexed lists.
- terraform
- iac
- meta-arguments
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Data sources in Terraform
What a data source is in Terraform, how its reading works internally (plan or apply), and why an explicit depends_on is sometimes needed.
- terraform
- iac
- data-sources
About me
8+ years operating Kubernetes platforms at scale and building internal developer platforms. IaC with Terraform/KCC, observability, FinOps, and custom tooling in Go, Python, and Bash.