Blog

Practical software engineering guidance from Jeff Bailey on tools like jq, SSH, and Git, plus architecture diagrams, book summaries, and fundamentals.

What Is Graph Engineering?

October 8, 2026 · 12 min · Jeff Bailey
Graph engineering designs an AI agent’s control flow as nodes, edges, and shared state, so loops become visible, pausable, resumable, and testable.
What Is Graph Engineering? A silhouetted person faces a tangle of light on the left that resolves into a network of glowing nodes joined by looping arrows.

Learn Zsh: Globbing, Expansion, Completion, History, and a Command Reference

October 6, 2026 · 16 min · Jeff Bailey
Learn zsh fast: glob qualifiers, parameter expansion, arrays, completion, history, options, key bindings, and .zshrc, plus a verified command reference.
Learn Zsh cover: a silhouetted figure faces a dark hallway and glowing blue and orange rooms of folders, under the title "Learn Zsh"

Learn Nushell: Tables, Pipelines, Data Files, and a Command Reference

October 3, 2026 · 15 min · Jeff Bailey
Learn Nushell fast: tables and pipelines, JSON, CSV, and TOML files, records, lists, custom commands, and config, plus a searchable command reference.
The words Learn Nushell over a silhouetted person lifting one glowing row from orderly streams of blue light while tangled threads fade behind.

What Are AI Evals?

October 1, 2026 · 10 min · Jeff Bailey
AI evals explained: how datasets, graders, and scores tell you whether a language model feature works, and why vibe checks and benchmarks fall short.
AI evals: test cases pass through an AI system to a grader, which scores them.

Learn Tmux: Sessions, Windows, Panes, and a Command Reference

September 27, 2026 · 11 min · Jeff Bailey
Learn tmux fast: sessions, windows, panes, the prefix key, and .tmux.conf, plus a searchable command reference and curated videos, podcasts, and books.
“Learn” in white and “Tmux” in yellow appear above a desk silhouette facing a glowing grid of rooms, connected by a broken thread of light.”

jq Cheat Sheet: Filters, Operators, and Output Formats

September 25, 2026 · 9 min · Jeff Bailey
jq cheat sheet for the command line: selecting values, select filters, reshaping objects, arrays and math, string helpers, output flags, and error meanings.
JQ Cheat Sheet title over a silhouetted figure guiding streams of blue and orange light through a row of glowing lens rings that narrow it into a clean beam.

Fix: ssh: connect to host github.com port 22: Connection timed out

September 21, 2026 · 4 min · Jeff Bailey
Your network blocks SSH on port 22, not your key. Route GitHub over ssh.github.com on port 443, make it permanent in ssh config, and verify with git.
Fix: SSH Port 22 Timeout title over a silhouetted figure holding a light before a sealed dark gate while a glowing orange path curves around it to a bright citadel.

Fix: Support for Password Authentication Was Removed

September 21, 2026 · 4 min · Jeff Bailey
GitHub rejects your Git password over HTTPS. Switch the remote to SSH, or create a personal access token and store it, so pushes stop asking.
A terminal showing a git push rejected because password authentication is not supported.

Fix: Too Many Authentication Failures

September 21, 2026 · 4 min · Jeff Bailey
SSH offers every key you own and the server cuts you off after six. Pin one key with IdentitiesOnly, and learn why GitHub gives a different error.
Fix: Too Many Auth Failures title over a silhouetted figure holding one glowing key before an arched gate lit by a column of lights, a huge ring of keys beside them.

Fix: Host Key Verification Failed

September 20, 2026 · 4 min · Jeff Bailey
SSH stops with “Host key verification failed.” Read the warning correctly, decide whether the key really changed, and fix it without disabling checking.
Fix: Host Key Verification Failed title over a silhouetted figure facing two glowing masks, one blue and one orange, above a red warning line.