Practical engineering patterns for reducing LLM costs in production apps.
AI features are getting easier to build, but harder to operate profitably. Once you move beyond a prototype, every model choice, repeated request, oversized context window, retry, tool definition, test run, reasoning setting, and real-time call can quietly turn into margin leakage.
Most AI cost problems are not just model pricing problems. They come from engineering choices that compound as usage grows.
using expensive models for simple tasks
allowing repeated identical calls at runtime
sending too much context
breaking prompt caching
using reasoning when the task does not need it
running real-time calls that could be batched
testing against live models unnecessarily
failing to meter usage by feature, customer, or workflow
First batch
6 AI App Cost Leaks
Watch the first batch of videos and start applying practical cost controls to prompts, model routing, duplicate request handling, context management, caching strategy, reasoning settings, and batch workflows.
Your AI App Is Probably Using the Wrong Model
Every prompt in your AI application does not need to go to your strongest frontier model. Simple classification, field extraction, sentiment checks, short summaries, and fixed-format responses are often better handled by lighter models that are cheaper and faster.
Key idea
Route by task, not by habit.
Avoid Repeated Identical Calls
Repeated identical LLM calls are one of the easiest cost leaks to miss because they often look like normal usage. Use idempotency keys, request hashing, short-lived response caching, in-flight request deduplication, replay protection, rate limits, and stored generated results.
Key idea
The cheapest LLM call is the one you do not make.
Your Context Window Is Probably Your Biggest AI Bill
As teams add longer system prompts, chat history, retrieved documents, tool definitions, safety policies, JSON schemas, and runtime application data, every model call gets larger, slower, and more expensive.
Key idea
Long context is not a database.
Prompt Caching Only Works If Your Prompt Stops Changing
Prompt caching can reduce AI application costs, but only if your prompts are structured consistently. Stable content should come first, variable content should come last, and shared templates should keep prompt composition predictable.
Key idea
Stable prefix. Variable tail.
Stop Paying the Model to Think When It Doesn't Need To
Reasoning models are powerful, but simple classification, extraction, formatting, and short summarization tasks should use the lowest reasoning level that still produces reliable results.
Key idea
Match reasoning effort to task risk.
Batch Mode Is the Overnight Discount for AI Apps
Batch APIs trade real-time response guarantees for lower input and output token costs, making them a strong fit for nightly reports, CRM enrichment, document tagging, summarization, analysis, and backfills.
Key idea
Use real-time AI only when someone is waiting.
Who this is for
This series is for developers, founders, and engineering teams building AI features into real applications, especially if you are starting to see costs grow as usage increases.
calling LLMs from production code
embedding AI features into a SaaS product
managing multiple prompts, models, or providers
dealing with rising token usage
trying to control usage by customer or plan
adding AI features but worried about margin
moving from prototype to production
Related tools
These videos use examples from tools we are building at PredictabilityAtScale.