I Replaced My Side Project Backend with AI — Here’s What Broke First
Source: Dev.to
Experiment Overview
If you’ve been on the internet for more than five minutes lately, someone has probably told you:
“Bro, AI can write your entire backend now.”
I decided to run a small experiment: Could I replace most of my side‑project backend logic with AI‑generated code and prompts?
Short answer: yes.
Result: oh no.
The Side Project
- Simple backend (CRUD + auth + notifications)
- Nothing fancy, just something that worked
- Stack: REST APIs, database, some business rules that had “grown organically”
The Plan
- Use AI to generate controllers, services, and some validation logic.
- “Clean it up later” (famous last words).
- Move fast, break things — preferably not in production.
Assumptions
- AI is amazing at writing code.
- AI is terrible at understanding your assumptions.
Example
Prompt: “Generate an endpoint to send notifications.”
AI response: “Sure, I’ll retry failed notifications infinitely.”
Result: infinite retries, no back‑off, no limits, no circuit breaker. AI assumes:
- Network calls always recover.
- External systems are friendly.
- Rate limits are a suggestion.
Reality disagrees.
Security (Quietly)
Nothing crashed, which made it even scarier. AI happily:
- Exposed internal IDs.
- Logged sensitive payloads.
- Skipped edge‑case auth checks because “it looked redundant”.
The code was clean… invisible.
Lesson learned: If you don’t explicitly say “this is security‑sensitive”, AI treats it like a tutorial.
Business‑Logic Nuance
I asked AI to “validate whether a user is eligible for an action.”
AI:
- Checked basic conditions.
- Missed why those conditions existed in the first place.
Humans encode intent in ugly if‑statements and patterns. That difference matters more than I expected.
The Twist
AI excelled at:
- Boilerplate (DTOs, mappers).
- Test‑case scaffolding.
- Explaining my own code back to me.
It didn’t replace me.
Recommendations
If you’re tempted to try this (and you should, at least once):
✅ Use AI for
- Skeletons.
- Repetitive logic.
- Tests.
- Documentation.
🚫 Don’t blindly trust AI for
- Auth.
- Retries.
- Money‑related logic.
- Edge cases that exist because of a specific historical incident (e.g., “this edge case only exists because of a 2021 incident”).
Bottom line: AI is a brilliant intern, not your tech lead. My overconfidence broke the backend, not the AI itself. With better prompts and more tests, the outcome could be very different.