Kristijan Kralj
@kristijankralj.bsky.social
Helping .NET developers master the latest tech and industry best practices.
You don't need to be perfect.
But ignoring these?
That's how "legacy code" is born.
But ignoring these?
That's how "legacy code" is born.
July 30, 2025 at 6:23 AM
You don't need to be perfect.
But ignoring these?
That's how "legacy code" is born.
But ignoring these?
That's how "legacy code" is born.
10. Reinventing the wheel
Unless you're writing an ORM for fun... stop.
Use proven, maintained libraries.
Protect your time and sanity.
Unless you're writing an ORM for fun... stop.
Use proven, maintained libraries.
Protect your time and sanity.
July 30, 2025 at 6:23 AM
10. Reinventing the wheel
Unless you're writing an ORM for fun... stop.
Use proven, maintained libraries.
Protect your time and sanity.
Unless you're writing an ORM for fun... stop.
Use proven, maintained libraries.
Protect your time and sanity.
9. No logging or monitoring
You shipped it. Great.
Now how do you know it's working?
No logs = flying blind.
You shipped it. Great.
Now how do you know it's working?
No logs = flying blind.
July 30, 2025 at 6:23 AM
9. No logging or monitoring
You shipped it. Great.
Now how do you know it's working?
No logs = flying blind.
You shipped it. Great.
Now how do you know it's working?
No logs = flying blind.
8. Ignoring security
Validate input. Follow least privilege. Sanitize everything.
Security is not optional. Ever.
Validate input. Follow least privilege. Sanitize everything.
Security is not optional. Ever.
July 30, 2025 at 6:23 AM
8. Ignoring security
Validate input. Follow least privilege. Sanitize everything.
Security is not optional. Ever.
Validate input. Follow least privilege. Sanitize everything.
Security is not optional. Ever.
7. Poor database design
Bad schema = slow app, no scalability.
Think long-term when modeling data.
Bad schema = slow app, no scalability.
Think long-term when modeling data.
July 30, 2025 at 6:23 AM
7. Poor database design
Bad schema = slow app, no scalability.
Think long-term when modeling data.
Bad schema = slow app, no scalability.
Think long-term when modeling data.
6. Unreadable code
Write for humans, not machines.
If it takes 3 reads to understand your logic, you’re doing too much.
Write for humans, not machines.
If it takes 3 reads to understand your logic, you’re doing too much.
July 30, 2025 at 6:23 AM
6. Unreadable code
Write for humans, not machines.
If it takes 3 reads to understand your logic, you’re doing too much.
Write for humans, not machines.
If it takes 3 reads to understand your logic, you’re doing too much.
5. Unhandled exceptions
Full stack traces in responses = free roadmap for hackers.
Log errors internally. Return safe messages externally.
Full stack traces in responses = free roadmap for hackers.
Log errors internally. Return safe messages externally.
July 30, 2025 at 6:23 AM
5. Unhandled exceptions
Full stack traces in responses = free roadmap for hackers.
Log errors internally. Return safe messages externally.
Full stack traces in responses = free roadmap for hackers.
Log errors internally. Return safe messages externally.
4. Skipping unit tests
Too busy to test?
You'll be busier fixing bugs.
Too busy to test?
You'll be busier fixing bugs.
July 30, 2025 at 6:23 AM
4. Skipping unit tests
Too busy to test?
You'll be busier fixing bugs.
Too busy to test?
You'll be busier fixing bugs.
3. Tight coupling
Classes that directly depend on other concrete classes = zero flexibility.
Abstractions exist for a reason.
Classes that directly depend on other concrete classes = zero flexibility.
Abstractions exist for a reason.
July 30, 2025 at 6:23 AM
3. Tight coupling
Classes that directly depend on other concrete classes = zero flexibility.
Abstractions exist for a reason.
Classes that directly depend on other concrete classes = zero flexibility.
Abstractions exist for a reason.
2. Hardcoded values
If you love global search and refactor headaches, use magic numbers.
Otherwise: config files, constants, or DB settings.
If you love global search and refactor headaches, use magic numbers.
Otherwise: config files, constants, or DB settings.
July 30, 2025 at 6:23 AM
2. Hardcoded values
If you love global search and refactor headaches, use magic numbers.
Otherwise: config files, constants, or DB settings.
If you love global search and refactor headaches, use magic numbers.
Otherwise: config files, constants, or DB settings.
1. No input validation
Bad data gets in.
Everything breaks.
It's 10x harder to clean dirty data than to block it at the door.
Bad data gets in.
Everything breaks.
It's 10x harder to clean dirty data than to block it at the door.
July 30, 2025 at 6:23 AM
1. No input validation
Bad data gets in.
Everything breaks.
It's 10x harder to clean dirty data than to block it at the door.
Bad data gets in.
Everything breaks.
It's 10x harder to clean dirty data than to block it at the door.