Choosing an LLM and AI stack

Stage 2 of 9 · 6 lessons · ~2 weeks

Reasoning quality: when a bigger model pays off

Some tasks need a model that thinks before it answers, and some only need a quick, obedient one. Learn what reasoning models and effort settings do, why multi-step tasks punish small mistakes, and how to tell when the price of a bigger model is cheaper than the price of a wrong answer.

Start: Reasoning models and fast models

Lessons· one lesson for each topic, in this order

  1. 1Reasoning models and fast models
  2. 2Effort and thinking settings
  3. 3Why multi-step tasks punish small errors
  4. 4Instruction following
  5. 5When a bigger model pays for itself
  6. 6What benchmarks can and cannot tell youOptional

Start with· follow one of these

Practise

Keep handy

Also worth your time

Before moving on: Take the hardest five examples from your feature and run them on a fast model and on a reasoning model at two effort levels. Record correctness, tokens and time for each, then write one paragraph on whether the extra reasoning pays for itself using price plus the cost of errors.

Tauseef's advice
Do not reach for the biggest model by default, and do not refuse it on price alone. Count the steps, price a wrong answer, and test effort levels before switching models. Many teams find that the same model at a different effort level solves the problem.

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