[srinathkrishna]

I'm glad someone asked this question and one of my often quipped quotes is - if you squint hard, every software project is some kind of a migration. And there are some excellent suggestions by others.

Having led my fair share of migrations in the past and going through one right now, here are my tips.

- Understand your stakeholders and the teams that are impacted. Spend enough time understanding how the system is being used today. Proxying and abstractions are you friend here. Just get as much data as possible.

- Once you get enough data, make sure to crunch and very importantly, have a means to surface this to the users. More often than not, for systems that have organically grown, you'll be surprised that users themselves don't know how they use an API.

- As much as possible, try to move things seamlessly. You can always do some portion of the migration without users knowing it. This can be as simple as introducing a translation layer or even you making code changes for the users to review them.

- If you're working on a timeline here owing to external factors like vendor contracts, cert expiry dates etc., make sure to buffer in at least a quarter (or possibly more). There will be new discoveries along the way.

- There will always be teams/stakeholders who will oppose to you asking them to do this work. I can't stress this enough - make sure to get your leadership on board. If you have a Program Management Office, make them your best friends. For anything that escalates and gets political, you as an engineer are better served to get the job done and an aligned leadership that backs you will help you fight these stragglers.

- Ultimately, love what you're doing. There's a mistaken understanding that migration work is not as sexy as greenfield work. I truly believe greenfield work is manifold simpler than migration. A migration is more like changing the wheels and the engine of a car as its running. There will be a lot of tradeoffs that have to be made and this is where engineering skills come into the picture!

All the best! :)