[devnexus 2026] Stop Fighting Your AI: Engineering Prompts That Actually Work

Speaker: Martin Rojas (@martinrojas)

See the DevNexus live blog table of contents for more posts


Slides online

General

  • Prompting is the new code switching [it took me a minute to realize he meant the ENglish language one]

Components

  • System Message – sets behavior and role
  • Instruction – what to do
  • Context – background data
  • Examples – pattern demonstration
  • Constraints – output limits
  • Delimiters – section separation

Markdown

  • Most common prompting language. Still text but gives structure
  • Headings, bold, list, code

Prompt types

  • Zero shot – direct instruction – simple/fast but inconsistent quality
  • One shot – format setting – consistent format, but limited pattern learning
  • Few shot – pattern learning – adapts to context, but token intesive
  • Role based – behavioral framing – consistent voice, but might override other instructions

Techniques

  • Clarity and specificity. Need to define assumptions
  • Chain of thought -make the model think like an analyst
  • Format constraints – specify what want for output
  • Prompt compression – use less tokens to say equivalent thing. Drop filler words like please. Use lists instead of sentences. Use a little quality, but worth it if minimal effect on output. Engineering tradeoffs.
  • Progressive enhancement – Naked prompt (vagye, add role, add specificity, add chanin of thought, add constraints, add validation

AI as Coach

  • Ask AI to improve your prompt; both with why and to rpdouce and improved prompt
  • Ask AI to compress to make shorter

More notes

  • Build prompt library that works for you – uses Obsidian and in the AI tools themselves (aka skills)
  • Measure for your use cases

Advanced Patterns

  • Tree of Thought (ToT) – explore multiple analytical approaches simultaneously then evaluate which version reals the most insight. This is why AI goes off for an hour; it is doing this behind the scenes
  • Self consistency – try different approaches and then majority vote for accuracy
  • ReAct pattern – Iterative reason > Act > Observe loops for multi step investigations

My take

Good start by defining vocabulary/components and good example. I’m really glad he shared the slides. The contrast between the text and background made the examples hard to read so I pulled up the deck on my computer for reading those.