Home on Jose Fernandez

mdserve 1.0: Markdown Preview for Coding Agents

Sat, 07 Feb 2026 12:00:00 -0700

When I introduced mdserve last year, I blogged about it as a tool for AI coding agent workflows, but the project itself never said that. The README called it a “fast markdown preview server with live reload and theme support.” Generic on purpose. People started using it for things I never intended: replacing MkDocs, hosting documentation.

With v1.0, I’m dropping the ambiguity. mdserve is a companion tool for AI coding agents. That’s what it was built for, that’s how I use it, and that’s the only direction it’s going.

Whiteboarding with AI

Sat, 04 Oct 2025 21:00:00 -0600

Coding agents often produce better results when you don’t ask them to write code immediately. If you jump straight to execution without thinking through the design, the code quality suffers. I’ve found it better to whiteboard the problem first. It’s like pairing with a senior engineer. You enter a room, map out the problem space, explore solutions, and sketch architectural diagrams. Instead of a whiteboard, it’s Markdown. And instead of losing the work when you erase it, the session persists as a design document.

Introducing mdserve: Fast Markdown Preview for Terminal Workflows

Mon, 22 Sep 2025 21:00:00 -0600

As coding LLM agents get better, I find myself using IDEs less and less. These days, my workflow is mostly Claude Code and Neovim. I don’t think I need a full IDE anymore for most work.

But there was one thing I missed from IDEs: built-in markdown preview. AI-assisted coding involves a lot of markdown work, and instant visual feedback is valuable.

The Problem

Most markdown preview tools are designed as IDE plugins or require dependencies like Node.js. I wanted something that is just a binary - no installation, no dependencies, no complex setup. Just a single executable that works anywhere and I can run from a terminal.

Noisy Neighbor Detection with eBPF

Wed, 11 Sep 2024 00:49:31 -0600

I recently co-authored a post on the Netflix Tech Blog where we detailed how we’re continuously monitoring the Linux scheduler using eBPF to enhance system observability. By instrumenting the scheduler, we gain real-time insights into CPU resource contention and noisy neighbor issues, all with minimal overhead. This method allows for deeper visibility into Linux performance, improving stability across our multi-tenant infrastructure. For more on how we implemented this, check out the full post here!

Packaging a Rust Program for Fedora

Sun, 25 Aug 2024 00:49:31 -0600

Packaging a Rust program for Fedora may seem daunting initially, but it’s more straightforward than expected, thanks to excellent documentation, Rust-specific tooling, and a helpful community. Over the past two months, I packaged bpftop, a process monitor for eBPF programs. While there were some specific considerations with Rust, the process was manageable. In this post, I’ll share the steps I took, the insights I gained, and how to streamline the experience.

About

Mon, 01 Jan 0001 00:00:00 +0000

I’m a systems engineer building compute infrastructure and container runtimes at Netflix. I contribute to the Linux kernel, created bpftop, and work deep in the stack with eBPF and Rust.

Contact

You can reach me at: me@jrfernandez.com

Connect with me on:

bpftop

Mon, 01 Jan 0001 00:00:00 +0000

bpftop is a monitoring tool I created to provide real-time insights into the performance of eBPF programs.

Read more about it in the blog post on the Netflix Tech Blog.

Media coverage

InfoQ - https://www.infoq.com/news/2024/03/netflix-launches-bpftop/
LWN.net - https://lwn.net/Articles/963767/
The New Stack - https://thenewstack.io/netflix-releases-bpftop-an-ebpf-based-application-monitor/
console.dev - https://console.dev/tools/bpftop/

Linux kernel

Mon, 01 Jan 0001 00:00:00 +0000

I started contributing to the Linux kernel in 2024. My primary focus is in the eBPF subsystem. I have submitted to the following patches:

bpf: Improve program stats run-time calculation
- Released in v6.10
drm/amd/display: Fix division by zero in setup_dsc_config
- Released in v6.10
bpf: add bpf_task_get_cgroup kfunc
- Rejected
kbuild: control extra pacman packages with PACMAN_EXTRAPACKAGES
- Released in v6.12
kbuild: add debug package to pacman PKGBUILD
- Released in v6.12

mdserve

Mon, 01 Jan 0001 00:00:00 +0000

mdserve is a fast, lightweight markdown preview server I created for terminal-based workflows.

Key Features

Zero dependencies: Just a single binary
Lightning fast: Built in Rust
Live reload: Auto-refreshes when files change
Beautiful themes: Built-in Catppuccin support (Latte, Macchiato, Mocha) plus additional themes

Installation

macOS:

brew install mdserve

Linux:

curl -sSfL https://raw.githubusercontent.com/jfernandez/mdserve/main/install.sh | bash

Cargo:

cargo install mdserve

Usage

mdserve README.md

The server starts up and provides a local URL to view your rendered markdown. Use the 🎨 button to switch between themes.