Justin Castilla

@elastic_devs I built an Elastic MCP server to help plan my commute to and from home, work, and events in my calendar. Reduces my traffic time and eases the daily commute:

We need to go deeper. 🌀 Flox environments stack and I'm nerding out on it. Activate one inside another and the prompt shows every layer: flox [test-py313 myapp tools] $ Here's a 3-layer setup and why it's handy

Layering has been in Flox for a while, but I think it's really useful. Clone my demo, run three commands, see it for yourself:

Bwahhhhhhhhh

RT @floxdevelopment: What happens when you point a coding agent at a real, messy codebase and ask it to sort out the dev environment? Justin (Our DevRel Lead <3) put our `floxify` skill to the test on Mastodon, a challenging repo (with Ruby, Node, PostgreSQL, Redis, native dependencies, multiple services) to build from source. The skill went through the repo, figured out what it needed, built the Flox environment, checked it, hit a few problems, fixed them, and kept going until `flox activate` worked. All in just a couple of minutes. The result: a declarative, reproducible Mastodon environment without using containers, and without Justin (or an agent) having to reverse-engineer the setup from scratch. He also tried the `flox` skill for a new project, starting from what he wanted to build rather than an existing codebase. Two different starting points, same idea: Give the agent what it needs to quickly set up the runtime environment. This way it spends tokens running and testing code instead of debugging setup. Justin wrote up the whole experiment, including what worked, what broke, and what the skills did about it 👇

Just wrapped up an amazing day at @WeAreDevs with a Lego Salon collab event with @floxdevelopment @apify and @runpod . So many people came out to have fun after the conference building Legos, chatting up what they saw, and cheering on our 3 winning groups. So much fun, everyone!

I think it's only right and natural to be freshly 44 and only now in my King Keimson era

Hey all, @floxdevelopment , @runpod , and @apify will be running an afterhours meetup at the @WeAreDevs venue on 9/24 right after the booth crawl. We'll be having some refreshments, networking, and an epic Lego building competition! See you there!

Wrapping @DevOpsDaysPDX 2026! TL;DR: the platform work you've already done is what saves you when AI hits your pipeline. Best talk for me: Daniel Sauble's Nix ignite. Containers fix reproducibility yet wreck DX. Nix fixes both, down to glibc. Also got to meet the Flox folx IRL!

Some shots of Nick, Daniel, and I at our booth at @DevOpsDaysPDX , so great to chat with the team and get a brain dump from the true talent! #DevOpsDays #DevOpsDaysPDX

Most important for me: Daniel Sauble's talk on reproducibility vs DX. Containers fix one and wreck the other. venvs fix DX until polyglot apps and system deps show up. Nix does both, down to glibc. Best pitch for Nix I've heard in a while. Great to meet the Flox folx IRL!

Beyond the AI sabre-rattling: IaC and supply chain security (talk to me about this), database branching and zero-downtime migrations (please don't), a rare four-distro Linux panel, and a hot take on config management via OpenVox.

Clear thread this year: the platform work you've already done is mostly what saves you when AI shows up in the pipeline. And when it fails, the failure modes are stranger and costlier than anything in your runbooks.

RT @ronefroni: The Go podcast let us hijack an episode to talk about Nix n Flox. 😅 (❤️ @sudomateo &amp; @skriptble) Dug a bit into.. Why Nix can feel hard. Why there's 5+ paths for every goal. Bringing Nix to work. And what we are cooking at @floxdevelopment #NixCon very soon ;) #NixOS

Ever wonder how NixOS works? In this week's episode of Fallthrough @sudomateo and @skriptble are joined by @ronefroni and @jambay to talk about NixOS and Flox. They get into what NixOS exists to solve and how Flox helps with that mission.

RT @ronefroni: @jambay demo'd the new @floxdevelopment Determinstic Agentic Stacks side by side with our friends at @inngest , @nebiusai , and @MiniMax_AI. Shoutout to our friends at @UnikraftCloud who swung by and are geniuses behind some incredible MicroVM speed! #nixos

Hey everyone! I'll be presenting a workshop on @LangChain 's Deep Agents agentic harness with @elastic agent builder and @tavilyai this friday at the Women in Data Science Conference. Register for the event here:

We'll build out an app to gather framework sentiment anlysis, repository liveliness metrics, and overall evaluation scores to offer up a "developer advocate" service to those wanting to vet the best tech out there.

Deep Agents helps coordinate the subagents to perform individual dedicated tasks, Elastic Agent Builder assists with the natural language queries on previous research, and Tavily reaches out to pull down the most up-do-date information. Should be a great time!