Personal Website of Ranjib Dey

The Through-Line From Chef to Agentic AI

· 6 min read

The first time I cared deeply about infrastructure as code, the argument was not really about Chef.

Chef was the tool in front of us. It gave us cookbooks, recipes, resources, and a DSL for describing how machines should be configured. But the deeper argument was that operational knowledge should not live only in tickets, shell history, wiki pages, and the heads of a few senior engineers.

If a server needed a package, file, daemon, permission, or dependency, that intent belonged in code. If a change could break production, it deserved version control, review, testing, and a release path. If an operator repeated the same judgment, the system should eventually learn it as an artifact.

Treating Context Like Code

· 6 min read

The more I use coding agents and LLMs for real work, the less I think of prompts as throwaway text.

A useful prompt is not just a question. It is a small interface. It carries assumptions, constraints, examples, preferences, and failure modes. A project instruction file is even more explicit: it tells an agent how to navigate a codebase, what quality bar to hold, which tools to prefer, and which boundaries not to cross. A context pack does the same thing for a domain. It packages durable facts, active goals, source notes, open questions, stale claims, and sensitive exclusions so an agent can reason from the right starting point.

Reliability Work Starts With Naming Failure

· 2 min read

Reliability engineering often starts with tooling, but the durable work starts earlier: naming what actually fails.

My public talks on resiliency and incident management span from DevopsDays India in 2013 to Uber-focused talks in 2020. The shape changed over time. The early framing was culture, tools, and practices. The later framing was incident taxonomy, data, and large-scale operational learning. The through-line is the same: resilient systems are built deliberately, not wished into existence.

reef-pi and Public Engineering Lessons

· 3 min read

reef-pi started as an open source Raspberry Pi reef tank controller. The public record now shows something larger: a hobby controller that grew into a small ecosystem of software, documentation, community support, and compatible hardware.

That arc is interesting to me because reef-pi is not only about aquarium automation. It is a compact example of how public engineering systems mature when they need to survive real users, real hardware, and long-lived maintenance.

Platform Engineering Through Automation

· 3 min read

Looking back across my public talks and writing, the same idea keeps returning in different forms: operational work should become software.

In the early 2010s, that meant Chef, infrastructure as code, and testing cookbooks. At PagerDuty, it meant CI/CD for infrastructure, TDD in operations, and service discovery with Consul. At Uber scale, it meant production engineering, capacity management, incident taxonomy, and ML-assisted operational decisions.

The tools changed. The direction did not.