(Abridged) slides from Re:Develop 19 The story of how I learned to work effectively with legacy code. Legacy Code is a fact of life for almost any software engineer. But what does Legacy Code mean? How do you end up with Legacy Code? How do you get stuff done when you have to work with it? How can you make it better? How can you be a better engineer for working with it? In this talk, I’ll be taking you through my journey of learning to work with Legacy Code. We’ll take a look at answering these questions, and how I overcame the challenges of working with Legacy code through my tasks, collaborating my team, and getting stuck in. Every engineer has had to take on the challenge of working with Legacy Code at some point in their careers, and if they haven’t yet, then you soon will! Working with Legacy Code can be daunting but it shouldn’t be. Attendees of this talk will obtain: An understanding of Legacy Code obstacles A knowledge different tools to help with working with Legacy Code Applying different techniques to help overcome common obstacles with Legacy Code

1. (My Journey to)
Working Effectively with
Legacy Code
Daniel Brown

2. About Me
Software Engineer for 6 years
Currently at: BBC (5 months)
Previously: eBay (5.5 years)
Usual disclaimer:
Views and opinions are my own…
@_dlpb

3. Let me take you on a Journey

4. Let me take you back in time

5. How do I feel when I come to work?

6. And then one day...

7. How do I feel coming to work?

8. Why did I feel like that?

9. So what is Legacy Code

10. So what is Legacy Code
Legacy Code is … code from the past, maintained because it works
Michael Feathers
http://bit.ly/30PJ6s3

11. You can’t escape it

12. So, you’re working on a legacy project?

13. So, you’re working on a legacy project?

14. That’s all very negative
So what can you do about it?

15. It can affect your mental state
If you only look at it as something bad, it will only ever be something bad
*Not an expert

16. You could switch jobs

17. You could switch jobs

18. Negatives to Positives

19. Gain Control
Perseverance is key
Back to School
Retrospect regularly
Learn the System
Refactor Safely
Create a Safety Net
Talk to others
Get Investment from the Business
Learn your IDE
Learn where to invest and draw the line
Form a plan

20. A story of how

21. A story of how

22. A story of how
Get Investment
Learn your IDE
Learn Where to Draw the Line

23. A story of how
Learn the System
Form a Plan
Talk to Others
Create a Safety Net
Refactor Safely

24. A story of how
Congratulations!

25. But it doesn't stop
there

26. Continuous Improvement

27. Continuous Improvement
Tests
Plan
Documentation
Retrospect

28. Continuous Improvement
It’s not as bad as you think

29. Fin

30. Links
● Michael Feathers, Working Effectively with Legacy Code (Paper), http://bit.ly/30PJ6s3
● Dan Pink, Ted Talk on Incentives, http://bit.ly/1Ba8st
● Martin Fowler, Refactoring Techniques, https://refactoring.com/
● Michael Feathers, Working Effectively with Legacy Code (Book) http://bit.ly/2LgOzCM
● Kevlin Henney, 97 Things Every Developer Should Know (Boy Scout Rule), http://bit.ly/2ZqMddv
@_dlpb