Three services
Pricing engine: 52,000 → 3,400 lines. Cost: $5.8M → $375K. Credit decisioning: 68,000 → 4,200 lines. Cost: $4.8M → $320K. Document generation: 45,000 → 2,800 lines. Cost: $3.2M → $280K. Three services. $13.8M → $975K.
Slide 01
Chen's pricing engine: built in 2015. 52,000 lines. Costs $5.8M annually to maintain. Eight minutes with AI coding tools: 3,400 lines of working code. Annual cost: $375K versus $5.8M. 93.5% cost reduction on one service. Ninety days later: $32M freed from a $50M budget.
Slide 02
Built 2015. Annual maintenance cost: $5.8M. Four months of human work to regenerate. "Whatever you do, don't propose a rewrite. We tried twice. Both failed."
3,400 lines of working code. Handles 99.4% of cases. Misses edge cases like billionaires with Bitcoin collateral. Annual cost: $375K versus $5.8M.
Roughly 50 weird cases a year handled manually. Previous cost of automating every edge case: $5.8M. Give away one $180K car per year. Still save $5.4M.
Cost us $15K annually in manual reviews versus $5.8M in perfect automation. At the macro level, I'll give away a free $180K car once a year if it means saving $5.4M.
What the CFO heard — and then asked: "How many services can you do this to?"
Slide 03
Pricing engine: 52,000 → 3,400 lines. Cost: $5.8M → $375K. Credit decisioning: 68,000 → 4,200 lines. Cost: $4.8M → $320K. Document generation: 45,000 → 2,800 lines. Cost: $3.2M → $280K. Three services. $13.8M → $975K.
Total code: 1.2M lines → 180,000 lines (15% of original). Release cycle: quarterly → weekly. Legacy cost: $40M → $12M. The VP of Engineering who said "don't propose a rewrite" is now running the blitz.
Final code: 1.2M lines → 120,000 lines (10% of original). Legacy cost: $40M → $8M. Budget freed: $32M (64% of total). Edge cases encountered: 187. Manually handled: 187. Cost: $8,500.
Slide 04
Two failed rewrites did not prove rewriting is impossible. They proved that human-led rewrites at that scale, with that team, using those tools, failed. AI changes what is possible in eight minutes that previously required four months.
The CEO's question was "what if things break?" The answer: "Then we handle them. We give white-glove service. If we accidentally approve a weird loan, we make him a customer for life. That is still cheaper than spending $40M maintaining perfection."
Slide 05
Slide 06
Pick one service. The most expensive to maintain. Run eight minutes of AI regeneration on it. If it handles 95%+ of cases, you have your proof point. Present the math the way this CTO did: total cost of legacy, total cost of regeneration, total cost of edge case handling. Let the CFO run the calculator.
The VP of Engineering who said "don't propose a rewrite" became the person running the blitz. People follow results, not proposals. Run the experiment. Show the number. Ask for 90 days.