Engineering Case Study — June 2026

Dev: The Follow-Up Agent
Where The Real Money Is Made

Every business loses leads in the gap between "How much?" and "Let's book it." Dev closes that gap — not by selling harder, but by following up forever. Here's the complete engineering breakdown.

Agent: Dev Role: Follow-Up Desk Stack: 4-stage nurture engine Live: June 7, 2026

The Problem Nobody Talks About

Here's a number that should make every business owner uncomfortable: 70-80% of leads who ask for a quote never book. Not because the price is wrong. Not because the service is bad. Because life gets in the way. They get busy. They forget to reply. The message gets buried.

Most businesses treat these leads as dead. They asked for a quote, you sent it, they went quiet — move on. But those leads aren't dead. They're warm. They expressed interest. They gave you their phone number. They opened a conversation. They just need someone to keep it warm.

That someone is Dev.

70-80%Leads who go quiet after quote
4Nurture stages
5Safety checks before send
48hOutbound guard window

What Dev Actually Does

Dev is not a chatbot. Dev is not an auto-responder. Dev is an autonomous follow-up agent that scans the CRM every 30 minutes, finds leads who have gone quiet, and sends them a personal, context-aware SMS based on exactly where they are in the sales cycle.

When a lead asks Steve (the sales agent) for a quote and then goes silent, the clock starts. Dev has one job: get them back.

The 4-Stage Nurture Sequence

StageWindowMessage TypeExample
Nudge 4–24 hours Soft check-in "Hi this is Dev from My Air Con Care, your conversation got sent to my desk. Just checking you got the quote ok? Any questions?"
Discount 24–72 hours Value offer "Hey, still keen? Just wanted to let you know we've got a $30 off winter special running — happy to lock that in if you're interested."
Article 3–7 days Educational "Came across this and thought of you — worth a read if you've got 2 minutes. Turns out dirty air cons can cause long-term lung damage."
Monthly 7+ days Stay on radar "How's things? Still need that air con sorted? No pressure — just making sure you're looked after."

Dev Never Stops

Unlike a human salesperson who gives up after 2-3 attempts, Dev follows up forever — or until the lead books, says "stop," or converts. The monthly nurture stage keeps leads warm indefinitely. Every message is personal. Every message references their actual conversation. And every message costs fractions of a cent to send.

The Engineering

Scanner — Finding The Right Leads

Dev's scanner runs every 30 minutes (or when the queue is empty) and queries the CRM for contacts matching three categories:

Cat 1 — Blast Follow-Up (50 max) Contacts who received a campaign blast and didn't reply. Staged at 18-30h (F1), 42-54h (F2), 66-78h (F3) intervals. Cat 2 — Hot Lead Nurture (10 max) Contacts where Steve sent a quote or date offer >4h ago with no reply. Staged into the nurture sequence based on hours elapsed. Cat 3 — Return Re-Engage (10 max) Past customers dormant 30-90 days. Seasonal check-in.

Each lead gets a DEV job card — separate from Steve's cards — that tells Dev exactly what stage they're at and what message type to send. The card includes the full conversation history so Dev can reference their actual situation.

The 5 Safety Checks

Before Dev can even think about drafting an SMS, Gate 1 runs five checks against every contact:

CheckWhat It VerifiesOn Failure
1. DNCContact is not Do Not Contact, blocked, or bad numberDelete queue row permanently
2. Active BookingContact has no hold or confirmed bookingSkip — they're already booked
3. Steve QueueContact is not being actively handled by SteveSkip — don't interfere
4. Needs DateIf contact needs a date offered, route to Anna insteadPOST to Anna API, delete row
5. Outbound Guard48-hour minimum between outbound messages (2h for hot nurture)Skip — respect the window

Separation of Concerns

Dev is deliberately limited. He never quotes prices (that's Steve's domain). He never offers dates or time slots (that's Anna's domain). If a lead needs a date, Dev outputs FLAG_FOR_ANNA instead of a draft, and the system routes the lead to Anna for a slot offer. If a lead replies with a booking question, Steve takes over.

This separation means Dev can never break the business. He can't double-book. He can't misquote. He can't spam an active customer. He can only do one thing: keep warm leads warm.

The Numbers That Matter

54Leads queued on Day 1
50Blast follow-ups
4Hot nurture leads
24/7Always running
6Gates per send
$0Per follow-up cost

Here's the math. A split system clean is $250. A ducted clean is $350+. If Dev converts just 2 extra leads per month that would have otherwise gone cold, that's $500-700 in revenue — for a system that costs approximately $0.002 per follow-up SMS (Claude API + SMS delivery).

The ROI isn't a percentage. It's a multiplier.

The Real Maths

If 200 people a month ask for a quote and 70% go quiet (140 leads), and Dev converts just 5% of those (7 extra bookings at $250 each), that's $1,750/month in recovered revenue — from a system that costs under $100/month to run. That's not marketing spend. That's revenue that was already in the database, just never followed up.

The Bootstrap — How Dev Thinks

Dev's entire identity is defined in 4 lean Markdown files — 3,086 bytes total. No code changes required to modify his behaviour. Update the markdown, restart the container, and Dev has new rules.

SOUL.md (885B) Who Dev is. His identity, tone, and introduction: "Hi this is Dev from My Air Con Care, your conversation got sent to my desk..." AGENTS.md (1,066B) His process. The nurture sequence, decision types (SEND / NO_SMS / FLAG_FOR_ANNA), urgency tiers. claude-prompt.md Rules and output format. What he can and can't do. (795B) Banned phrases. Output format spec. system-prompt.md Container-level context. Just enough to orient the (314B) model before each job.

Actual Drafts From Live Testing

"Hi Georgia, Dev from My Air Con Care — your chat got sent to my desk. Saw you were sorting bills when we last spoke, hope that's all worked out! Still keen on the air con? No rush, just checking in."
"G'day Jayde, it's Dev from My Air Con Care. Curran's Hill is sweet, we cover that area. You still keen to get your ducted system cleaned?"
"Hey Fazil, it's Dev from My Air Con Care — your chat landed on my desk. Saw you were asking about getting your split system done in Blacktown. Still interested?"

Every draft references the contact's actual suburb, actual system type, and actual conversation context. No templates. No merge fields. No "Dear [Name]." Just an AI agent who read the conversation and responded like a human.

Infrastructure — Separate Channel, Separate Security

Dev runs in his own Docker container with his own bootstrap, his own token locker channel (port 5559, separate from Steve's 5558), his own curfew valve, and his own queue table. If Dev's container crashes, Steve and Anna are unaffected. If Steve's token locker is compromised, Dev's channel is still secure.

dev-scanner.js Finds quiet leads → builds DEV cards → INSERTs dev_queue │ dev-valve.sh 8am-8pm AEST circuit. PM2 managed. │ dev-pull.sh FIFO queue drainer. Spawns dev-process.sh per phone. │ dev-process.sh Gate 0 → docker exec claude-dev → Draft → Gate 1-6 │ Token Locker :5559 Dev's separate GPG channel. PC passphrase never crosses. │ Join API → SMS Via Android phone. 48h guard. Hot nurture: 2h minimum.

The Lesson For Any Business

Most businesses spend their money on the wrong thing. They buy ads to get new leads while 140 warm leads sit in their database with no follow-up. They pay receptionists to answer the phone but not to re-engage the people who called last week and went quiet.

Dev flips that equation. The real money isn't in the first message. It's in the second, third, and fourth.

The follow-up desk is where the margin lives. It's the difference between a $250 job that books and a $250 job that evaporates because the customer got busy. It's the lead who asked for a quote in May, forgot to reply, and would have booked in June if someone just checked in.

Dev never forgets. Dev never gets busy. Dev never decides a lead is "probably not interested" and stops trying. Dev follows up at 4 hours, 8 hours, 24 hours, 3 days, 7 days, and every month after that — forever — until the lead books or says stop.

And it costs less than a cup of coffee per month to run.

Want a Dev For Your Business?

If you've got a database full of leads who asked for a quote and went quiet, we can build you a Dev. Same engine. Same nurture sequence. Your business, your voice, your rules.

Get a Free Business Audit →

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