Published in


Migrate your Large Scale Enterprise into AWS

From @rayhennessy on Unsplash


AWS Re:Invent is one of the best times of the year for technical innovation in the cloud. In this article, we will cover AWS’s recommended methods for large scale cloud migrations. In my experience, the most important thing you can do during these migration scenarios is to under-promise, over-deliver, and over-communicate.

Communication saturation is especially important to IT leaders, as they will be required to provide updates to their executive teams, and those executive teams will be required to report to their boards, so it is always nice to include executive summaries in communications around what your cloud migration team is working on.

I’ll be breaking things down into chunks, so please feel free to send me a message and let me know if this works for you, or how you would change it up for the future!

Executive Sponsorship

Arguably the most impactful thing for a successful cloud migration is having 100% buy-in from the executive team. Having an executive team that understands the benefits that the cloud will bring their company, as well as an executive team that will rally the troops during the difficult parts of the migration, will make the migration go much more smoothly and it will be far more enjoyable for all parties.

For the most impact, it is AWS’s recommendation that the executive team forms a “cloud leadership team,” that meets weekly, or bi-weekly, to discuss the progress of the migration, any blockers, and the paths forward. In my experience, having weekly check-in calls with your organization drivers can help keep everyone focused, and looking towards the future, rather than worrying about the here-and-now.

AWS recommends forming what is called a “Cloud Center of Excellence,” otherwise known as a team of engineers whose specialty is cloud based. These teams typically consist of: AWS infrastructure engineers, security engineers, application engineers, operations engineers, and your lead architect, who would be responsible for design and oversight.

The Three Phases of Migration

AWS has labeled 3 phases for large scale cloud migrations: Assess, Mobilize, and Migrate and Modernize. We will go into those phases below.


The assessment phase is where AWS’s tools for migration really shine. In this phase, AWS migration engineers can utilize the AWS Migration Evaluator to help them form a business case for migration, then the migration team can assess business readiness using the AWS Migration Readiness Assessment, and finally, the lead architect can track migration progress using the AWS Migration Hub. Below, we will go into further detail on these tools and their uses for an AWS Migration.

The AWS Migration Evaluator

The Migration Evaluator is a collector that requires a dedicated server (Windows 2k12R2 or greater) to run on, and it will provide clear oversight into the cloud migration. AWS’s idea here is that the Migration Evaluator will help your Cloud Center of Excellence (CCoE) build a data-driven business case for your cloud migration. The Migration Evaluator supports all sorts of server mediums, including VMWare, Hyper-V, bare metal servers, and SQL Server!

Once the Evaluator completes its inventory gather, it will output a number of “deliverables,” such as data insights, cost estimation, and savings plans.

The Migration Readiness Assessment

This assessment is a step taken to help you objectively determine your “potential for migration success” based on AWS’s cloud adoption framework. You get a dedicated AWS Solutions Architect to help you go through the 70 question assessment, honestly answering them, and helping you reach an organization consensus. This assessment will output a recommended action plan for your organization’s specific needs.

The Assess phase will provide you and your organization with the information you need to properly plan for your upcoming cloud migration, and also highlight any potential pitfalls or blockers that you may run into.


The mobilize phase is when you and your organization work together to create a migration plan, where you can begin to plan to address any of the blockers discovered in your assessment phase. It is in this phase that we are introduced to the 6 migration strategies: Refactor, Replatform, Repurchase, Rehost, Relocate, Retain, and Retire. More detail on the 6 strategies can be found in AWS’s blog post on the subject.

Landing Zones

In the title of this section, I linked the product page for AWS Landing Zones, where you can find a much deeper explanation of what Landing Zones are and their benefits. In this section, we will go into the basics.

Diagram Explaining Landing Zones

AWS Landing Zones are a great place to start for building your cloud infrastructure. A Landing Zone will provide your AWS account with secure, scalable multi-account environment equipped with AWS’s best practices, a playground for experimentation, and just a general starting point for your migration.

Setting up a Landing Zone gives you an easily managed, cross-account accessible environment with SSO capability, allowing you to integrate your already existing SSO solutions into AWS. Once you have configured your SSO and login capabilities, and gotten the basics covered in the above screenshot configured, you are ready for what AWS describes as an “account vending machine.”

An account vending machine is a centralized area for account deployment, standardization, and baselines. This will allow you to quickly and painlessly deploy new account into your infrastructure, with less lift than a non-Landing Zone setup.

The Mobilize phase is generally the phase that allows your cloud engineers to shine their brightest, so it is typically my favorite phase.

Migrate and Modernize

The Migrate and Modernize phase is where you begin to take action on all of your planning. This is where your cloud engineers will begin designing and migrating your applications, and validating that they are ready for usage in the cloud.

In the assess phase, you should have chosen one of the 6 cloud migration strategies for each of your applications, and in the Migrate phase, you will employ this strategy.

In my experience, this most common method of migration is re-platform, or, as the blog post calls it, “Lift, Tinker, and Shift”. This means you are taking your applications and servers, ripping everything off of them and generally updating the underlying infrastructure to the latest and greatest (Windows 2019 Datacenter, and macOS 5.10 at the time of publication).

I’ve found that many organizations are rightfully worried about their technology budget and that using the re-platform method is simply the fastest and cheapest method for migration. This is not always the case, as some applications are not prepared for the “latest and greatest,” but that is something you will discover during your assessment phase.

For the Migrate phase, AWS has a veritable mountain of tools that they provide to their users. Arguably the most powerful (and definitely one of my favorites) is CloudEndure Migration, which is a tool that allows you to greatly simplify your migrations, automating almost the entire process for you. CloudEndure requires an agent to be installed on the source server. Once that agent is installed, CloudEndure will bein a discovery process, and prepare a cutover instance in AWS. It will begin syncing data to the instance as soon as it is ready, and will allow you to engage a cutover at will, with a minimal downtime window.

Another extremely powerful service that AWS offers for cloud migrations is AWS Database Migration Service, or DMS. According to the linked product page for DMS, it supports “homogenous migrations… as well as heterogeneous migrations between different…platforms.” As with CloudEndure, I’ve personally used DMS and can vouch for the fact that it is easy, fast, and reliable once it is set up. Furthermore, DMS supports many of the widely used database types. For a full breakdown, make sure to visit the linked product page.


After today’s Re: Invent presentations, I learned that a stunning ~80% of infrastructure is still on-premises. That is an absolutely astoundingly large number that I foresee will begin to trickle lower as the years go on. Cloud migration has been gaining steam for years, and I believe with the current pandemic, the whirlwind surrounding cloud migrations has reached a fever pitch. More organizations than ever have moved from just “discussing” the cloud, to actually building their cloud environments and migrating their infrastructure into the cloud.

Hopefully, this article proves useful for your introduction to cloud migrations. Again, the most important step of your migration is executive sponsorship, so make sure to keep your executives constantly apprised of your migration progress!

If you enjoyed reading this article, please feel free to check out my other Medium articles, and to visit my LinkedIn, where I am active and always willing to chat about all things AWS.

👋 Join FAUN today and receive similar stories each week in your inbox! Get your weekly dose of the must-read tech stories, news, and tutorials.

Follow us on Twitter 🐦 and Facebook 👥 and Instagram 📷 and join our Facebook and Linkedin Groups 💬

If this post was helpful, please click the clap 👏 button below a few times to show your support for the author! ⬇



Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store