"running 5 migration-architect subagents in parallel"
Turns out Claude Code can be quite helpful for legacy modernization 😀
But it's really all about automating your workflow and knowledge rather than magic LLMs doing everything in one shot.
#architectureModernization #legacyModernization
👉 Architecture Modernization in Legacy AWS Cloud-Native Systems
www.knowhowcode.dev/articles/mod...
#aws #architecturemodernization #softwarearchitecture
Modernization will almost certainly increase pressure on your bottlenecks so it's important to identify them in advance.
Things will get worse before they get better as you start to unpack all the dependencies and address the neglect.
#legacyModernization #architectureModernization
Those 6 months spent iterating towards a simple solution could prevent creating legacy that slows your business down for years, and unlock major new possibilities.
2/2
#architectureModernization #legacyModernization
I think sometimes there are simple solutions for complex problems. It just takes a lot of trial and error and determination to find them.
At the end it seems so obvious: "why did it take you 6 months to design such a simple solution?"
1/2
#architectureModernization #legacyModernization #ddDesign
Coding assistants can now help us to identify, fix, and prevent legacy crystallized semantic drift.
It's going to be fun to see how all this fits together with @chrissimon.au's @contextive.tech...
3/3
#legacyModernization #architectureModernization
Every time I add or refactor code, the agent knows about this and tries to use preferred terminology.
Semantic drift is a big problem in legacy systems. It increases the costs and risks of modernization legacy-modernization.io/patterns/leg...
2/3
#legacyModernization #architectureModernization
This week I created a cursor rules file: domain-terminology.mdc. It explains key domain concepts used in the code.
More interestingly, it also explains terminology mismatches - where the code doesn't align with the current business terminology.
1/3
#legacyModernization #architectureModernization
Can coding assistants help with legacy modernization? Here's what I learned today.
I manually wrote a 4 step approach to creating a migration plan and asked Cursor with Claude 4 Sonnet to execute each step.
1/3
#legacyModernization #architectureModernization
My new side project is live - @legacy-modernization.io
I curated my knowledge of legacy modernization patterns into a website.
I still have lots of content to add but the current version is hopefully a bit useful
legacy-modernization.io
#legacyModernization #architectureModernization
legacy-modernization.io is now live !
A collection of patterns and other resources to help you modernize your legacy systems effectively.
Community contributions welcome.
#legacyModernization #architectureModernization
A feature that would take 1 day in greenfield can take weeks or months in legacy
Also "How could we improve the product even further in greenfield that we are blocked from doing in the current system?"
#architectureModernization #legacyModernization
I had a great week speaking at Infoshare in Gdasnk and Craft Conference in Budapest, about legacy architecture migration patterns.
Slide decks are available here:
- drive.google.com/file/d/1kl4-...
- drive.google.com/file/d/1k5kM...
#architectureModernization #ddDesign #legacyModernization
I recently designed and facilitated a legacy migration hands-on exercise with @indu-alagarsamy.bsky.social at #exploreDDD
The Miro board is here if you'd like to run the exercise yourself: miro.com/app/board/uX...
#architectureModernization
You need to create a mechanism to sync the new with legacy data. You need to ensure:
- all modifications to the data legacy data correctly trigger the sync
- your new app correctly builds the right state
- eventual consistency is acceptable
2/3
#architectureModernization
Evolution of code model and mental model over time. At the start they are the same, but with each evolution they start to get more and more mis-aligned.
An under-appreciated benefit of architecture modernization is the chance for semantic convergence (of your software and mental model).
It's common in legacy systems for words and concepts not to align with how people think and talk about the business.
1/4
#architectureModernization #dddDesign
Re-orging the company wouldn't fix the legacy systems or culture, for example.
#architectureModernization #legacyModernization
3/4
Generally I recommend avoiding the last option as you lose some of the benefits of modernization.
I also prefer to avoid having special code paths, so cleaning the data is probably my preference.
But every scenario is unique and there are many trade-offs to consider.
#architectureModernization
"Another team made a change which caused a bug in our application. It took us ages to find and fix their problem."
How do people in your company respond in situations like this?
#architectureModernization #archMod
1/3
Option A - business-ish events from legacy, Option B - contextless state-change events from legacy
When publishing events from legacy I prefer events that indicate business intent, like a business process starting.
But it's hard to do reliably, e.g. multiple flows that produce the same events but are subtly different (e.g. for different types of user or product).
1/3
#architectureModernization
Diagram of 2 options: unrestricted legacy model events and translating legacy events into new model and republishing
Publishing events from legacy is a common way to incrementally modernize. You can expose it's data & capabilities without rewriting it.
But the events coming out of legacy represent your old model. And you will need to translate them into your new model.
1/4
#architectureModernization #ddDesign
Bi-directional legacy model sync. Write operations can happen in the legacy or new system, and the updates need to be synchronised with the other side
One of the trickier legacy migration patterns is the bi-directional legacy model sync. Where new and old run in parallel.
Write operations can happen in either. E.g., customers via a website and partners via API - both creating/modifying the same entities.
1/4
#architectureModernization
Architecture modernization is a risky game that will test your engineering leadership and culture.
Rewriting, migrating, running new and old in parallel, keeping multiple data-stores in sync... it's inevitable that there will be issues in your production environment.
1/3 #architectureModernization
This week I had the chance to attend KanDDDinsky in Berlin and it was great.
Thanks to all the organizers and attendees for an excellent few days.
And thanks to Eduardo da Silva for another enjoyable and memorable collaboration.
Slides: drive.google.com/file/d/1LajO...
#architecturemodernization
#ArchitectureModernization with @nicktune.bsky.social
Recording (Video / #Podcast) available!
#SoftwareArchitekture im #Stream
software-architektur...
Thumbnail: Nick Tune about Architecture Modernization
#ArchitectureModernization with @nicktune.bsky.social
#SoftwareArchitekture im #Stream
TODAY 13:00 CEST
More Information and opportunity to ask qustions:
software-architektur.tv
#ArchitectureModernization with @nicktune.bsky.social
#SoftwareArchitekture im #Stream
TOMORROW 13:00 CEST
More Information and opportunity to ask qustions:
software-architektur...
Nick Tune about Architecture Modernization - Thumbnail
#ArchitectureModernization with @nicktune.bsky.social
#SoftwareArchitekture im #Stream
Friday 13:00 CEST
More Information and opportunity to ask qustions:
software-architektur.tv
