What Claude Gets Wrong (And Right):
The 80/20 Reality of Building with AI
Rob · Gloucestershire Claude/AI Community Meetup
Robin Smith
Operator · Acquirer · Builder
20+ years in enterprise software
US & Europe
Operator-led acquirer
Did a load of M&A, it almost killed me. Now focused on acquiring smaller businesses, particularly holiday home agencies
Cheltenham for 10 years, now Cirencester
Married, 2 kids
Average cricketer and golfer
Corinium Capital & stayd
What Claude Is Great At: Claude → Gamma
Spec in Claude. Render in Gamma. Decks in minutes.
Claude's Role
Structures arguments and writes precise slide copy.
Gamma's Role
Turns structured content into polished presentations.
The Catch
Explicit input works best because Gamma's LLM is weaker.
The 80/20 Rule
Gets you 80% there fast. The last 20% is where the savings disappear.
⚡ 80% Fast
Quick momentum.
⚠️ Final 20%
Savings disappear.
Problem 1: Confident Bullshit
Claude invents menus, buttons and steps that don't exist — with total conviction.
Can't See Your Screen
It cannot verify what's in front of you.
No Confidence Dial
No way to signal uncertainty.
The Obsidian Disaster
Wrong file path, invented UI, 15-min task took hours.
Verify Everything
Check every menu path. Every. Single. Time.
Problem 2: The Loop of Doom
Same fix. 15 times. No reflection. Real cost: 3 bugs, 11 attempts, 3hrs downtime.
Try Fix → Fails Slightly → Loop Again
No reflection, no reset.
Bug 1: Timezone Crash
Hidden in production, Cloudflare Workers.
Bug 2: Debugger Broke Everything
Every fix looked broken.
Bug 3: Wrong Payment Parameter
Stripe mandate crash.

Three Round Rule: three tries max, then reset. One feature, one conversation.
From Zero to Shipping: The AI Coding Stack
18 months ago I couldn't deploy a web app. Here's the progression that changed that.
Lovable
No-code AI builder. Great for getting something on screen fast. Hit the ceiling quickly.
Cursor
AI-powered IDE. Proper code, proper control. Where things got serious.
Claude Code
Agentic coding in the terminal. The current frontier. Where I live now.
I can now credibly release functional, open source software.
While building workflow automation that pays the bills.
"Real" world costs
Via OpCode: https://opcode.sh/
"For context, a mid-level developer at ~$150k/year costs roughly $75/hour. Four days of dev time would be ~$2,400. So Claude did it for ~58% of that cost, and likely faster."
AI + Human vs Human-Only: The Real Numbers
4 days of AI-assisted dev vs 1.6 years traditional. 6 repos. Real numbers.
60,960
Net Lines of Code
Shipped in just 4 days
4
Days Total
vs 406 days human-only
15,240
Lines/Day (Claude)
vs ~150 lines/day human

Build-only. Testing, debugging and maintenance not included. AI cost = £1,120 Claude + £1,600 human operator.
Questions?