Marketing engineers: the new 10x employee

1. 01A marketing engineer is the person with the idea and the person who can build it, in one body. Part marketer, part builder.
2. 02Every era of marketing made a test cheaper. Now one person can run dozens a day, and whoever learns fastest wins.
3. 03Before any agent, build the brain: one folder that explains the business like a first-day onboarding.
4. 04Then build six agents, one at a time. Guardrails go in the tools, not in the prompt.
5. 05More tests only pay off if the ideas stay specific. Volume with thin context is just slop.

The best ones often don't start in marketing at all. Greg names founders, engineers, operators and solo builders.

Agent

An AI helper set up to do one job on its own, like reading sales calls or making ads. On this page every agent reads the brain folder before it does anything.

Context

What an agent knows about your business before it starts. Greg says that when agent output is bad, the problem is almost always the context.

Slop

Lots of generic AI output made on thin context. Many tests, weak insight.

Markdown file (.md)

A plain text file with light formatting. Every file in the brain folder, like voice.md or customer-fit.md, is one.

Guardrail

A hard limit on what an agent can do, like email access that can only draft or ads that launch paused. Greg says it belongs in the tool, because a rule in the prompt is only a suggestion.

Closed-lost

A deal that sales worked on and didn't win. The closed-lost agent rereads these to find the real reason and when to try again.

CTR

Click-through rate: the share of people who see an ad and click it. The creative agent kills any ad under 1%.

Churn

When customers stop paying and leave. Cheap customers who churn in 60 days look good on a dashboard and quietly lose money.

Hook

The opening line or first seconds of an ad or post. Greg tests hooks as free posts first and only pays to promote the winners.

AI actors

AI-made people who read your script on video, in dozens of languages. Greg names Arcads and HeyGen.

Organic

Posts you publish for free on your own accounts, as opposed to paid ads.

CRM

The system where a company tracks its customers and deals. Greg says most CRMs hold a pile of unfinished revenue.

1. Mad Men

   1950s to 1990s

   Print, TV, radio, billboards. Millions per campaign, results a quarter later. Ran on taste and gut.

   A few a year

2. Digital marketer

   2000s

   AdWords (2000) and Facebook ads (2007) made every click countable. Life inside dashboards.

   A few a month

3. Growth hacker

   2010s

   Viral loops and A/B tests, like Hotmail's email footer and Dropbox's invite-a-friend storage. Every idea still waited on an engineer.

   A few a week

4. AI-assisted marketer

   2023

   ChatGPT sped up copy and images. The org chart, the meetings and the six-week cycle stayed. Most teams are still here.

   Better drafts, same pace

5. Marketing engineer

   Now

   One person researches the customer, builds the page, makes the creative, wires the data and launches the test.

   Dozens a day

Specific marketing got cheap. When specific is cheap, the company that understands its customer best starts winning.

mkdir -p growth/{company,evidence,brand,workflows,campaigns,measurement,decisions,permissions}
touch growth/START-HERE.md \
  growth/company/customer-fit.md growth/company/offers.md \
  growth/brand/voice.md growth/brand/founder-opinions.md \
  growth/decisions/failed-campaigns.md

The three files that matter most

• customer-fit.md

  Who buys, who stays, who you can serve at a profit.

  Be painfully specific. “Shopify stores doing $1M to $10M a year where the founder still does the books” gives an agent something to work with. “SMBs” gives it nothing.

• voice.md

  How you sound.

  Skip adjectives like “friendly but professional.” Paste three emails or ads you loved and two you rejected, with one line on why for each. Agents learn from examples.

• founder-opinions.md

  Your unfair advantage.

  Competitors have the same models. Only you have your founder's takes on the category, the customer and the competition. Two hours of writing them down and the output starts to sound like you.

1. 01

   Customer language agent

   Reads every sales call and support ticket and pulls out the exact words customers use for their problem.

   Scheduling software for plumbers: owners keep saying they're tired of taking calls during dinner. That line is the ad, the headline and the sales opener. People buy the situation, not the feature.

   Build this one first. Everything else feeds off it.

2. 02

   Buying trigger agent

   Watches for events that create demand overnight: a second location, a funding round, starting to sell wholesale.

   Before it suggests an account, it has to finish one sentence: this event creates this problem, and our product solves it this way.

   If the sentence comes out mushy, the account waits. That filter is what makes outreach feel like good timing, not spam.

3. 03

   Search agent

   Finds the questions people ask right before they buy and builds the most useful page on the internet for each one.

   Every week, ask ChatGPT, Claude and Perplexity your buyers' questions and log which companies they recommend.

   That log shows exactly where you're invisible.

4. 04

   Creative agent

   Makes ads, launches them paused so a human hits go, and kills anything under 1% CTR.

   Ask for different reasons to buy, not fifty versions of one headline. Name each ad after the idea it tests: “dinner angle beat price angle” is a lesson, “video_final_7 won” is trivia.

   Decide what counts as a win before launch, or 200 ads give you 200 inconclusive experiments.

5. 05

   Closed-lost agent

   Rereads every lost deal and records the real reason plus a reopen condition, like “needed SSO” or “competitor contract renews in March.”

   The day SSO ships, everyone who asked for it gets a personal note that quotes their original call.

   Greg's pick for the one that pays for everything else. Most CRMs hold a pile of unfinished revenue.

6. 06

   Performance agent

   Writes a short memo every Monday where every line ends in a decision: keep, kill, change or test.

   Wire it all the way through to profit, not clicks.

   Cheap customers who churn in 60 days look great on a dashboard and quietly lose money.

The agents, what they make and their guardrails are Greg's. Which files each one reads and writes back to is FakeNerd's mapping onto his folder layout; he lists the folders, not the wiring.

1. 01

   Test hooks for free

   Post ten hooks as organic TikToks, Reels or X posts. Only put ad money behind the ones that take off.

2. 02

   One long piece into twenty

   A podcast, webinar or founder rant on a walk becomes a month of clips (Opus Clip). Carousels built from the customer language report are easy to make and get saved a lot.

3. 03

   Listen where people complain

   Point an agent at Reddit, X and competitors' reviews. It reports the week's complaints and drafts helpful replies that you post yourself.

4. 04

   Put the founder to work

   When every brand can generate content, a real person with real opinions is the scarcest thing on the feed. Turn founder-opinions.md into a post a day that you edit and publish.

• Agent workspace

  Claude Code · Codex · Cursor

• Writing

  Claude · ChatGPT · Gemini

• Images

  Nano Banana · GPT Image

• Video

  Veo · Kling · Runway

• AI actors and voice

  Arcads · HeyGen · ElevenLabs

• Clipping and editing

  Opus Clip

• Customer voice and CRM

  Gong · Intercom

• Signals

  Clay · Apollo

• Measurement

  PostHog

1. 01

   Build decision tools

   A box-size calculator that cuts a shipping bill. A migration checker that shows what moves over cleanly. Once six-month projects, now a scrappy week. Buyers bookmark them and come back when they're ready.

2. 02

   Market to the influencers

   The accountant who recommends software to forty clients, the agency that picks tools for its customers. Each gets its own campaign with exactly what they need to say yes.

3. 03

   Fix acquisition inside onboarding

   Sometimes the ads work and new customers churn because week one is confusing. An agent reading onboarding tickets can beat your next ad set.

4. 04

   Connect clicks to revenue

   Give every campaign an ID and carry it everywhere: links, ad names, email sequences, CRM deals. Most companies have clicks by campaign and revenue by customer, and can't join them. Whoever does owns the best dashboard in the company.

5. 05

   Keep the customer's words alive

   A sharp insight goes through a summary, a brief and five rounds of edits and comes out sounding like every other ad. Attach the original quotes to every campaign so every agent sees them.

6. 06

   Get better every week

   Every rejection gets a written reason, saved where the next run will see it. If you spend all day fixing agent output, the problem is upstream, and it's almost always the context.

Greg's bet: the next decade goes to whoever understands their customer best and acts on it fastest. By 2028 he expects the best marketing teams to be one or two marketing engineers running dozens of agents. Want more? He did a full episode on it.

Related on this site: Nicolas Cole's digital brain, voice and approved language without slop, close to voice.md. Inside a company brain, one shared memory a whole team's agents read from. The Agency, ready-made agent personas, marketing included, if you'd rather start from someone else's.

• All ideas, examples, the folder layout, the six agents and the tool list are Greg Isenberg's, from “The new 10x employee (and 99% of companies don't have one)”, Greg's Letter, Oct 5, 2026. FakeNerd retold and regrouped it. Subscribe to get the original.
• The experiment-frontier and five-eras panels are FakeNerd rebuilds of Greg's own sketches (gregisenberg.com).
• Podcast: Marketing Engineer: The $1M Job with AI Agents · The Startup Ideas Podcast on YouTube, Apple, Spotify
• Greg Isenberg: X · gregisenberg.com
• The one-line folder setup command is FakeNerd's addition.