The worst way to use a coding agent is also the most popular.
Type a wish. Receive a brick of code. Paste it. Hope.
That is a vending machine. Vending machines are fine for chips. They are a bad model for changing a living codebase.
Treat the agent like a pair programmer who is fast, tireless, and occasionally confidently wrong. You stay the driver for decisions. It stays the driver for typing when you allow it.
Pairing habits that transfer
In human pairing, you talk goals, you navigate together, you challenge assumptions, you take small steps.
Do the same with the agent.
- Share the destination and the non-goals
- Point at the files that matter
- Ask for a plan before a patch
- Integrate in slices
- Review continuously, not only at the PR
If you only show up at the end, you are not pairing. You are accepting deliveries from a stranger.
Context is the real interface
A vending machine needs coins. A pair needs context.
Attach:
- the error
- the failing test
- the screenshot
- the module boundaries
- the “do not touch” list
Then ask questions that expose misunderstanding early. “What do you think this function is responsible for?” beats “make it work” nine days out of ten.
When the agent is wrong about the story, correct the story before any code lands.
Turn-taking beats one-shot novels
Use a rhythm:
- Plan in bullets
- You approve or edit the plan
- Implement one step
- Run tests
- Next step
Yes, it is slower than “rewrite the service.” It is faster than untangling a rewrite on Thursday after standup has found you.
If the agent tries to sprint ahead, pull the reins. Pairing includes saying “hold on.”
You still own taste and tradeoffs
The agent will offer clever abstractions. Clever is not free.
You decide whether you need an interface, a new package, or a two-line fix. You decide if performance matters yet. You decide if a dependency is worth it.
An agent that always gets to choose architecture will leave you with a museum of patterns. Your job is editorial.
Communication patterns that help
Narrate constraints. “We cannot change the API contract.” “Match existing logging.” “No new deps.”
Ask for alternatives. “Give me two approaches with tradeoffs. Do not code yet.”
Demand diffs. “Show the patch, not a full file dump.”
Force uncertainty. “List what you are unsure about.” Silence is not confidence. Silence is a missing section.
These prompts are social protocols. They keep the pair honest.
When vending-machine mode is OK
Sometimes you actually want a snack.
Boilerplate for a throwaway script. A regex you will verify. A CSV transform. A one-file experiment in /tmp.
Use the machine mode there. Do not use it on the payment service five minutes before a release.
Judgment is knowing which room you are in.
Teaching your team the difference
Juniors especially will treat agents like answer keys.
Coach them to paste the plan, not only the code. Ask them to explain the diff in their own words. If they cannot, they did not pair. They vendored.
Seniors need the opposite reminder sometimes: you are allowed to let the agent type the boring parts. Pairing is not proving you can suffer.
The emotional part nobody writes down
Vending-machine use feels magical when it works and cursed when it fails.
Pairing feels like work. That is why it works more often. It keeps your brain in the loop without pretending you must hand-type every character to be a real engineer.
You do not need to be nostalgic for suffering. You can still be allergic to mystery code.
Bottom line
A coding agent is at its best as a pair: shared context, small steps, constant review, human judgment on the wheel.
A coding agent as a vending machine will occasionally jackpot and frequently dispense something sealed that you should not eat.
Put the coins away. Sit down next to it. Drive.
