PTENES
Module 1.3

đź’¬ Prompt Engineering

Knowing how to communicate with AI is now a fundamental skill—like typing or using a spreadsheet. Master the essential prompt engineering techniques and understand how this skill has evolved into context engineering, the most valued skill in 2026.

7
Topics
50
Minutes
Basic
Level
Practice
Format
1

🎯 Progressive Specificity

The difference between a mediocre AI result and an exceptional one almost always comes down to prompt quality. Progressive specificity is the technique of building prompts from general to specific, adding layers of context, constraints, and examples until you get exactly the result you want.

Main Concept

An effective prompt generally contains 5 elements: (1) Context — who you are and what the situation is, (2) Task — exactly what you want, (3) Format — how the result should be structured, (4) Constraints — what should be avoided or respected, and (5) Examples — references for the expected result. Progressive specificity suggests starting with the task and iteratively adding the other elements, refining until the result is satisfactory.

Practical Tip

Compare these two prompts and see the leap in response quality:

Vague prompt:

"Write a professional email."

Specific prompt:

"You are a project manager at a technology consulting firm. Write a professional email to the client informing them of a 2-week delay in the project, explaining the reasons (an unexpected technical issue with the integration), presenting a recovery plan, and maintaining a confident, proactive tone. Maximum 200 words, 3 paragraphs."

Do

  • Include context, task, format, and constraints
  • Iterate and refine the prompt progressively
  • Specify the target audience and desired tone
  • Define the response length and structure

Avoid

  • One-sentence prompts without context
  • Assuming that AI "guesses" what you want
  • Accepting the first answer without refining it
  • Use ambiguous or vague terms
2

🎭 Role-Playing

One of the most powerful and simple prompt engineering techniques is assigning a role to AI. When you say "You are a digital marketing expert with 15 years of experience," AI activates more specialized and deeper knowledge patterns, generating significantly better responses than without that direction.

Main Concept

Role-playing works because LLMs were trained on texts by experts in every field. By assigning a role, you essentially "filter" the model's vast knowledge, prioritizing linguistic and conceptual patterns from that specific domain. You can create complex personas: "You are a CFO at a tech startup that just received Series A funding, with a background in McKinsey consulting." The more specific the persona, the more focused and useful the response will be.

Practical Tip

Create a personal library of personas that are useful for your work. Examples: “You are a rigorous copy editor” for reviewing text, “You are a tax attorney” for tax questions, “You are a career coach specializing in technology” for professional advice. Save these prompts to reuse and refine them over time.

Advanced Technique: Expert Debate

Ask AI to simulate a debate between two experts with different perspectives. For example: "Simulate a debate between a Keynesian economist and a classical liberal economist on AI's impact on employment. Each should present 3 arguments supported by data." This produces richer, more balanced analyses.

3

đź”— Chain-of-Thought

Chain-of-Thought (CoT) is a technique that dramatically improves AI’s reasoning ability by asking it to “think step by step” before reaching a conclusion. This simple addition can turn incorrect answers into correct ones, especially for logical, mathematical, and analytical problems.

Main Concept

When an LLM generates a response directly, it's essentially "taking a shot"—trying to predict the final answer all at once. Chain-of-Thought forces the model to build intermediate reasoning step by step before reaching a conclusion. Research from Google Brain and other labs has shown that this technique improves accuracy by 20-40% on reasoning tasks. There are variants such as Zero-shot CoT ("Think step by step"), Few-shot CoT (with reasoning examples), and Tree-of-Thought (exploring multiple paths).

Practical Tip

Add these magic phrases to your prompts:

  • "Think step by step before answering."
  • "Explain your reasoning before giving the final answer."
  • "First analyze the pros and cons, then present your recommendation."
  • "List your assumptions, then build the conclusion logically."

Do

  • Use CoT for logical problems and analyses
  • Ask AI to show its assumptions and reasoning
  • Verify each reasoning step
  • Combine with role-playing for better results

Avoid

  • Use CoT for simple, straightforward tasks
  • Trust the reasoning without checking
  • Ignoring it when a step seems wrong
  • Ask for reasoning without specifying depth
4

đź“‹ Few-Shot Learning

Few-Shot Learning is the technique of providing examples within the prompt so the AI understands exactly the desired pattern. Instead of describing what you want in words, you show examples of the expected result. The AI learns the pattern from the examples and applies it to new inputs with high fidelity.

Main Concept

The terms refer to the number of examples provided: zero-shot (no examples), one-shot (one example), and few-shot (2-5 examples). The more complex the desired pattern, the more examples are needed. Few-shot is especially powerful for specific formatting, data classification, style translation, generating content with a consistent tone, and any task where "showing" is easier than "explaining."

Practical Tip

Few-shot example for classifying review sentiment:

"Classify the reviews as Positive, Negative, or Neutral:

Review: 'Excellent product, exceeded my expectations!' -> Positive

Review: 'It arrived broken and the service was terrible.' -> Negative

Review: 'The product is okay; it does what it promises.' -> Neutral

Now classify: 'Fast delivery, but the quality could be better.' -> "

When to Use Few-Shot

  • Specific formatting: When you need output in a very specific format
  • Classification: When you want AI to categorize data consistently
  • Writing style: When you want to replicate a specific tone or voice
  • Technical translation: When terms need to be translated in a way that's specific to your context
5

✂️ Task Decomposition

LLMs have limitations with very complex tasks. When you ask for everything at once — "Create a complete business plan for an AI startup" — the result tends to be superficial and generic. Breaking tasks down solves this: you divide the problem into smaller parts, solve each one separately, and combine the results.

Main Concept

Decomposition follows the “divide and conquer” principle: (1) Identify the problem’s subtasks, (2) Solve each one with a focused, detailed prompt, (3) Use one step’s output as the next step’s input, (4) Combine and review the final result. This enables shorter, more focused prompts that produce higher-quality responses. It also makes it easier to identify and correct errors at specific steps.

Practical Tip

To create a business plan, break it down like this:

  • Prompt 1: "Analyze the [sector] market in Brazil. Size, growth, key players."
  • Prompt 2: "Based on this market analysis, identify 3 underexplored niche opportunities."
  • Prompt 3: "For opportunity X, create a value proposition and revenue model."
  • Prompt 4: "Project costs, revenue, and break-even point for the first 18 months."
  • Prompt 5: "Compile everything into a 1-page executive summary."

Do

  • Break big problems into clear steps
  • Use the output of one prompt as the input for the next
  • Review each step before moving on
  • Combine with CoT for complex steps

Avoid

  • Ask for everything in one giant prompt
  • Breaking things down into excessively small parts
  • Move on without validating the previous step
  • Lose sight of the big picture across subtasks
6

⚙️ Tools and Platforms

The generative AI tool ecosystem is vast and grows daily. Each platform has distinct strengths and weaknesses. Knowing the available options and how to choose the right tool for each task is a skill that multiplies your productivity and the quality of your results.

Main Concept

The AI model landscape in 2026 is more competitive than ever. The leading platforms are: ChatGPT (OpenAI, GPT-5.x family) — versatile and popular, with advanced reasoning models (o3, o4-mini); Claude (Anthropic, 4.x family) — a leader in long-document analysis (up to 1 million tokens), coding, and complex instructions; Gemini (Google, 3.x family) — integrated with the Google ecosystem, with advanced multimodal capabilities; and DeepSeek (China, open source) — which revolutionized the market by delivering cutting-edge performance at a much lower training cost. Beyond text, there are tools for images (Midjourney, DALL-E 3, Canva AI), music (Suno, Udio), and video (Kling AI 3.0, Runway).

Platform Comparison (2026)

  • ChatGPT (GPT-5.x): Natural conversation, deep reasoning (“o” models), image generation, and integration with tools
  • Claude (Opus 4.x): Analysis of long documents (1M tokens), advanced coding (Claude Code), security, and complex instructions
  • Gemini (3.x): Integration with Google Workspace, real-time web search, multimodal analysis, extended context windows
  • DeepSeek (V4): High-performance open source, affordable, with an option for privacy and local use
  • LLaMA 4 (Meta): Open source with up to 10M context tokens, ideal for customization and corporate use

Reasoning Models: The Big Breakthrough

One of the biggest innovations of 2025-2026 was reasoning models ("reasoning models"). Unlike traditional models that respond immediately, these models use extra computation to "think" before responding, generating internal reasoning chains. Examples include o3 and o4-mini (OpenAI), Claude with extended thinking (Anthropic), and Gemini Thinking (Google). They excel at math, coding, and complex multi-step tasks — making the Chain-of-Thought you learned in Topic 3 even more powerful when combined with these models.

Practical Tip

Don't commit to a single platform. Try at least 3 tools and use each for its strengths: ChatGPT for brainstorming and complex reasoning, Claude for analyzing long documents and coding, Gemini for research and up-to-date information, and DeepSeek when you need a powerful free alternative. Open-source models (LLaMA, DeepSeek) allow local use with complete privacy. Over time, you'll develop an intuition for which tool to use for each type of task.

7

🚀 Beyond the Prompt: The Evolution Toward Context Engineering

The techniques you learned in this module are fundamental — but the field has already moved beyond isolated prompts. In 2025-2026, the market began to value a broader skill called context engineering, which encompasses everything involved in designing the complete information environment an AI model receives to perform a task.

What Changed

In 2024, “prompt engineer” was touted as the profession of the future, with six-figure salaries. In 2026, Fortune and market analysts already consider the standalone prompt engineer role obsolete. The reason: writing good prompts has become a basic skill, like knowing how to type. The differentiator now is knowing how to design the complete context—memory, retrieved data, conversation history, system instructions, and tool outputs—that makes an AI agent truly useful. Gartner identified context engineering as a critical skill for 2026.

From Prompt to Context: The Scale of Evolution

  • Level 1 — Basic prompt: Write good questions and instructions for AI (what you learned in this module)
  • Level 2 — Advanced prompt: Combine techniques (CoT + role-playing + few-shot) for complex tasks
  • Level 3 — Context engineering: Design the entire information ecosystem: system instructions, persistent memory, retrieved data (RAG), tools connected via MCP, and user profiles
  • Level 4 — Agent orchestration: Coordinate multiple AI agents with distinct roles, working together on complex tasks

Real Example: Vibe Coding

Vibe coding is a perfect example of this evolution. Instead of writing prompts to generate snippets of code, the developer describes their intent in natural language, and an AI agent (such as Cursor, Claude Code, or GitHub Copilot) autonomously generates, runs, debugs, and iterates on the code. The focus shifts from "how to write the prompt" to "how to provide the right context"—relevant files, documentation, style examples, and project constraints. In 2026, 95% of developers use AI tools weekly, and the vibe coding market accounts for 25-30% of the AI code generation market (US$ 4,2 billion).

Practical Tip

Start by mastering the techniques in this module — they're the foundation for everything. Then, in the next module (1.4 — Context Engineering), you'll learn how to go beyond the prompt and design complete intelligent systems. The journey is: first, learn to communicate well with AI; then, learn to build the environment that makes that communication powerful. The two skills complement each other and together make you the professional most valued by the market in 2026.

Module Summary

Next module:

🧩 1.4 — Context Engineering