1) Missing Environment Details

Mistake: “Write a login route.” (No language, versions, frameworks.)
Fix: State language, version, runtime, and framework.

You are a Node.js 20 + TypeScript 5 engineer.
Framework: Express 4, JWT auth, PostgreSQL via pg.
Task: Implement POST /api/login with email/password.
Return: single file src/routes/login.ts + brief comments.
    

2) No Minimal Repro

Mistake: Paragraphs of context, no concrete inputs/outputs or error text.
Fix: Include Input → Error → Expected triple.

Input: POST /users {"email":"a@b.com"}
Error: 500 "cannot read property 'id' of undefined"
Expected: 409 with {"error":"conflict"} and no insert.
    

3) Asking for “Magic” One-Shot Solutions

Mistake: “Build a full CRUD app with tests and docs.”
Fix: Split into steps and request diffs or modules.

Step 1: Data model + migration (PostgreSQL).
Step 2: REST endpoints (GET/POST/PUT/DELETE).
Step 3: Jest tests (4 cases).
Return: one step only, unified diff format.
    

4) Vague Output Format

Mistake: Getting mixed prose + code you can’t paste cleanly.
Fix: Force a strict return shape.

Return:
- One fenced code block only (```ts)
- No prose before or after
- Include file path as first comment line
    

5) No Constraints or Standards

Mistake: Accepting any style, any library.
Fix: Specify style guides, lints, and dependency rules.

Constraints:
- ESLint: no-explicit-any, prefer-const
- Prettier defaults
- No external deps unless stated
    

6) Skipping Tests

Mistake: Shipping code without test scaffolding.
Fix: Ask for tests by default.

Return:
1) Function implementation
2) Tests (Jest/pytest) with 6 cases, covering edge cases and errors
    

7) Fuzzy Debug Requests

Mistake: “It doesn’t work; fix it.”
Fix: Ask first for diagnosis, then a minimal patch.

You are a Python 3.11 engineer.
Bug: TypeError at line 84 in parser.py: 'NoneType' is not iterable
Show:
1) Root cause hypothesis
2) Minimal diff patch
3) One failing + one passing test
    

8) Over-Explaining to the AI

Mistake: Screen-long context with no structure.
Fix: Use labeled sections and bullets; keep it scannable.

ROLE: Senior React 18 engineer
TASK: Refactor component to reduce re-renders
CONSTRAINTS: use memo/useCallback, keep ARIA labels
RETURN: unified diff only, no prose
    

9) Ignoring Security & Reliability

Mistake: Prompts that don’t mention validation, sanitization, or error handling.
Fix: Bake security concerns into the ask.

Add:
- Input validation (zod/schema)
- Parameterized queries (no string concat)
- Error taxonomy: 400/401/403/409/500 with JSON shape
    

10) No Iteration Loop

Mistake: Accepting the first answer as final.
Fix: Review, adjust constraints, and re-run prompts.

• Raise/lower word limits for tighter output.
• Switch to tables/JSON for comparisons or configs.
• Ask explicitly for performance notes or edge cases.

Copy-Ready Developer Prompt Templates

A) API Endpoint with Validation + Tests

You are a Node.js 20 + TypeScript 5 engineer.
Framework: Express 4. DB: PostgreSQL via pg.
Task: Implement POST /api/users to create a user.
Constraints:
- Validate input (email required, 6-60 chars, RFC 5322)
- Parameterized queries only
- Return {id,email,createdAt}
Return:
1) src/routes/users.ts (single file, full code)
2) Jest tests (4 cases: happy, invalid, duplicate, injection attempt)
    

B) CLI Utility (POSIX Shell)

You are a Linux CLI expert.
Task: Write a POSIX-compatible shell script to dedupe emails in a log file.
Constraints:
- No GNU-only flags
- Handle lowercase/uppercase
Return: single script with comments + usage example
    

C) Performance Refactor

You are a Python 3.11 performance engineer.
Task: Optimize a function that counts word frequencies in large files.
Constraints:
- Use generator streams
- Avoid loading entire file into memory
Return:
1) Optimized function
2) Micro-benchmark harness comparing before/after
    

Table: Before vs After Prompt

Before	After
“Write login route.”	Node.js 20 + TS5, Express 4, JWT; return single file + tests.
“Fix this error.”	Provide stack trace + repro; request root cause + minimal diff.
“Make it better.”	Define constraints (lint rules, deps) and required output shape.

Workflow Checklist for Dev Prompts

• State env (language, versions, framework, OS).
• Provide a minimal repro (input, error, expected).
• Specify a strict output format (single code block, diff, JSON).
• Add constraints (lint, deps, style guide).
• Request tests or benchmarks.
• Iterate with PromptScoreGPT to raise quality before you generate.

Conclusion

Developer prompts work best when they read like concise specs. Include environment, repro details, constraints, and a strict return shape. Make tests part of the ask, and keep an iteration loop. If you want a quick pre-check, paste your prompt into PromptScoreGPT—you’ll get a score and a stronger version to paste into ChatGPT.