Capstone, building a real system out of prompts
Not single prompts. A reusable, documented chain of tasks.
Level 2 was about Chain-of-Thought, system prompts, rolling context and tools. Now you turn those bricks into a system. Not a one-off, but something you can reuse two weeks from now.
The task
Pick a recurring task you spot in yourself. Real-world examples:
- Every Monday assemble a weekly plan from calendar + emails + Notion todos.
- For every LinkedIn comment decide answer/ignore/follow-up, with a draft reply.
- Before every customer presentation, build a briefing (who is the customer, last contacts, open topics).
- From a newsletter text, generate an Instagram post and a LinkedIn post, consistent in style.
What the system has to do
- Input defined. What exactly do you put in? An email? A calendar export? A customer name?
- Output defined. Which format? Which fields? Which length?
- System prompt written. In 4 to 8 sentences: the model's role, the rules that always apply, the output format.
- Chain-of-Thought where it makes sense. For tasks where the model needs to give a reason (e.g. "why is this comment important enough to answer").
- Tested with three different inputs. One easy case, one tricky case, one edge case. Look at all three outputs and judge them.
What you should produce
A file system.md in your capstone folder. Containing:
- What the system does (one sentence).
- Full system prompt.
- Input format (example).
- Output format (example).
- Three test runs with input and output.
- Assessment: where did it work, where did it fail, what would you change.
Plus the three outputs as separate files, exactly as they came out of the model, as evidence.
What's strong
The system is precise enough that someone else could pick it up 1:1. The system prompt is less than half a page but produces consistent outputs. You found at least one edge case where the model fails and documented how you handle it (fallback rule, or note "here I have to step in manually").
What's weak
A system that only works for one example. A 3-page system prompt full of "please be professional" phrases. No test, no assessment. "Worked great" with no evidence.
Bonus
Build the whole thing as a small loop where you feed in a new input once a week and the system runs. One page of documentation that explains how someone else would use the system. That's the leap from "I wrote a prompt" to "I built a tool".
Where it belongs
Folder portfolio/level-2-capstone/. And if it turned out well: include it in your talent-pool profile. Companies want proof of "can work systematically", not "wrote one good prompt".
Time
60 to 90 minutes. If it takes longer, the task is too complex. Start small.
Wrap-up
Take the Level 2 checkpoint. Then Level 3, where automation enters (Zapier, n8n, webhooks). From there, "writing prompts" turns into "building processes".