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LLM Engineering
2 September 20262 min readSritam Dash

How to Learn LLM Engineering with a Timeline

A month-by-month timeline for learning LLM engineering from tokenization to fine-tuning, with evaluation and context engineering keeping you building.

What LLM engineering actually is

LLM engineering is the work of getting a large language model to behave reliably in your product: prompt design, context management, retrieval, evaluation, and โ€” when needed โ€” fine-tuning. It is closer to systems engineering than to model research.

You will not train a frontier model. You will build applications on someone else's, and the skill is making one behave predictably enough to put in front of users. That is an engineering problem with an unusual failure mode: the component is probabilistic, so "working" has to be defined and measured rather than assumed.

A timeline you can follow

Weeks 1โ€“2 โ€” mechanics. Tokens, context windows, temperature, and how the model predicts text. Cover with how LLMs really work.

Weeks 3โ€“4 โ€” prompting. Role, context, constraints, and examples. Practice with prompt engineering 101.

Weeks 5โ€“8 โ€” grounding. Build a retrieval pipeline over your own documents. This is where most products live โ€” see RAG explained simply.

Weeks 9โ€“12 โ€” evaluation and safety. Create a test set, score answers, find hallucinations and add guards. Then decide (with data, not vibes) whether you need fine-tuning or can stay with RAG โ€” a question we break down in RAG vs fine-tuning.

The two skills that matter most

  • Evaluation: if you cannot measure quality, you cannot engineer it. Every change to a prompt should be tested against a fixed set of cases, and you should be able to say whether it got better or worse.
  • Context engineering: what you put in the window often matters more than the model. Retrieval quality, chunking, and ordering usually produce larger gains than switching to a bigger model.

Tools to learn

  • A vector store for retrieval.
  • An evaluation framework for regression tests on your prompts.
  • A tracing and logging tool so every call is inspectable.

The third one is the one people skip and then wish they had. When a user reports a bad answer, being able to replay the exact call with its context is the difference between a five-minute fix and an afternoon of guessing.

What the job actually involves day to day

  • Reading logs to find why a specific answer went wrong.
  • Tuning chunk sizes and retrieval filters, then re-running the eval set.
  • Writing guardrails for input validation and output checking.
  • Watching cost and latency per request.
  • Deciding when a model should refuse.

None of that is research. All of it is the work that makes the research usable.

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