Denny Springle talks about “ColdFusion Legacy app - Is a Refactor Better than a Rewrite?” in this episode of ColdFusion Alive Podcast with host Michaela Light.

“Refactoring is a way of taking in modernizing code that already exists, and bring it up to speed with generally modern best development practices. So you know, some object orientation, data modeling type of thing, as well as you know, either using a framework or building an application framework yourself, that hits all of the major obstacles that are that a framework will do for you generally”.

https://youtu.be/_assa85CJQc

Show notes

Why is refactoring vs rewriting important today?

vs 3rd option - leave the legacy app unchanged…

Risks and rewards for each, best approaches

Security, hacking risk and biz reputation

Dev elegy to spaghetti

Old style code with CF tags (vs CFscript 

Tech debt

Urge to rewrite 

What does refactoring mean?

Modernize existing code in place in production app

Adding/improving framework 

Improving datamodel

Incremental improvement that is always working

Opportunity to get into the depths of the code and business logic 

Reuse 

Security

Performance

Feature flags

New Ben Nadel book on this coming out soon

House in dark analogy 

What does rewriting mean (really)?

Understanding all the business logic and intelligence up front (and documented!)

What really is the biz problem being solved

No original devs or business users left 

May be to a new language, platform, database, OS/Cloud provider

Or may be the same language, new version/upgrade. 

Recreate data model

What are the risks and disasters of rewriting that you have seen?

He was the “rewrite kid” in younger days

Underestimate analysis time for understanding business logic

Underestimate time for coding and testing

Risk of project failure 

Users don’t accept the radically changed system or UX

Now is is the “refactor” man

He as seen 1 successful rewrite out of 5

Worse odds than Russian roulette!

Always 90% done

 After 6 mos “we are 90% done boss”

After another 6 mos “we are 90% done boss”

Rewrite tips

Extensive testing period, including beta testers (actual users)

Only do when simple biz logic or well documented biz logic or big changes in business (merger or regulation change)

Allow long shake down period after release

If possible do slow rollout (how good SaaS work) 

Walk us through your ColdFusion refactor process?

Agile sprint

Reusability (and maintainable)

A data model

Move to Common code, objects

Remove Deadwood code, tables, indices, and data

Move to a MVC framework

Why - code organization to Model, View and Controller parts of your code

MVC is a standard in most modern languages

Separating View code lets Switch out front ends - web vs mobile

Easier for UX coders to edit the View code without messing up the CFML code logic or SQL queries

Readability

FW/1 - lightweight

ColdBox - more features and ecosystem

CFWheels

Legacy non-maintained CF frameworks

Fusebox

Model Glue

REST API

REST API is a modern programming pattern

Many 3rd party REST API

All modern web programming languages use them

CF makes consuming or providing REST API incredible easy

One parameter in your CFC object!

Encapsulation of data model and business logic

Different front ends, same API

Not a microservices fan any more

Can become clunky and numerous

Cloud resources and cost go through the roof

Documentation may be lacking

Amazon Prime case study of moving away from microservices

Is Amazon moving away from microservices?

The migration of the Audio-Video Monitoring Service from Microservices to Monolith was a significant change in Amazon Prime Video's architecture.