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AI & Automation

Cost control for LLM features in production

Budgets, caching, and model tiers so AI remains a product cost—not a surprise invoice

November 14, 2025
By Manweba

LLM features fail quietly on the balance sheet: a helpful assistant that burns the margin on every support ticket. Cost control is product design—quotas, caching, and model choice—not a finance spreadsheet after the fact.

Put a budget next to the feature flag

Define a per-user or per-tenant daily token budget before launch. Soft-limit with a clear UI; hard-limit before you protect margin. Unknown spend is not “agile.”

Simple daily budget gate

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Cache and shrink before you scale models

Cache embeddings for stable documents. Cache identical system prompts. Summarize long threads before sending them. Smaller context beats a larger model for many tasks—and it is cheaper to measure.

Tier models on purpose

Route cheap classification to a small model; reserve frontier models for high-value drafts. Make the router explicit in code so costs are reviewable in PRs.

Model tier by job

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Instrument like any other dependency

Log tokens in, tokens out, model id, feature name, and tenant. Alert when spend velocity spikes. A weekly cost review belongs next to error-rate review—same ceremony, different graph.

Final thoughts

Treat LLM spend as a product constraint: budgets at the gate, cache before scale, tier models by job, and instrument usage like any paid dependency. Surprise invoices are a design failure.

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