Migration & Modernization
Navigating Conflicting Decisions in Your Cloud Migration and Modernization Journey
When one enterprise moved its aging systems to the cloud, the CTO faced a tough choice: rehost apps (lift and shift applications as-is) for speed or refactor (modify applications) for long‑term cloud benefits. Rehosting meant getting there fast but sacrificing efficiency, while refactoring promised scalability but delayed growth. This kind of trade‑off isn’t unique. From banks to startups, leaders wrestle with high‑stakes decisions—centralize or decentralize governance, single or multi‑cloud, in‑house expertise or partners—each with no clear “right” answer. In this blog, we unpack the common conflicting choices CIOs and CTOs face during cloud migration and modernization, and how these decisions define long‑term success.
Decision-Making in the Cloud: What’s Different?
Moving to the cloud is more than just tweaking your IT setup; it’s a game-changer. It’s not about migrating a few workloads and seeing what sticks. We’re talking about a real, thought-out game plan that changes how companies do business. Cloud adoption must be anchored to measurable business outcomes, ensuring every investment directly advances our strategic objectives and delivers tangible value. Operating on the cloud requires a fundamental mental model shift—from control to empowerment, from big bang launches to iterative delivery, from fixed infrastructure to flexible services. In traditional IT, success meant predictability and tightly managed change. For example, while the traditional approach is: “Buy servers to handle our busiest day,” with a cloud mindset we say: “Let’s pay for what we use and scale instantly.”
Principles of Making High-Quality Decisions
Success in cloud transformation hinges on making a small number of high-quality decisions at the right time. But speed and complexity often make it tempting to delay or default to “safe” choices. Here are key principles to guide better decisions:
Don’t make cloud decisions in isolation—anchor every cloud decision in a business objective: time to market, revenue, resilience, cost and so on. Focus executive attention on critical choices that drive long-term impact. Decisions do not necessarily require consensus, just commitment when chosen. Decisions do not have to be overanalyzed for every possible outcome. Many decisions are reversible (“two‑way doors”); a few aren’t (“one‑way doors”), so know the difference to manage risk without sacrificing speed. Test assumptions through pilots, uncover risks early, and avoid piling up vague, delayed choices. Push decisions to those closest to the work, with guardrails. In the cloud’s fast‑moving world, waiting for perfect clarity slows you down. As Jeff Bezos says, 70% information is often enough to make most decisions.
Decisions, Decisions, and more Decisions
Let’s get right into it. Here are the common but key decisions when adopting cloud.
Rehost vs. Refactor and others
Early in your cloud journey—or later, when moving new workloads—you’ll face a key choice: rehost apps as‑is or refactor them for the cloud. Rehosting, or “lift and shift,” moves applications without changing their architecture—faster and less disruptive, ideal when time is tight. Refactoring involves redesigning parts of the application to use cloud‑native features, which takes longer but delivers better efficiency, scalability, and cost savings. The right choice depends on business criticality, complexity, time, and ROI. For example, Dow Jones rehosted to meet a two‑month data center exit deadline, while Netflix refactored from the start to go cloud‑native. There are also other options, known as the 7Rs: Replatform (make minor cloud‑ready tweaks), Repurchase (move to SaaS), and Relocate (move virtual machines to the cloud unchanged), plus Retain and Retire. AWS Migration Evaluator can help assess your applications and guide this critical decision.
Centralized vs. Decentralized Governance Model
This decision sets the tone for how you govern, manage, and innovate in the cloud. Do you centralize for stronger control and consistency, or decentralize to give teams more agility and room to innovate? This decision usually comes up early during your cloud adoption journey and also when adoption scales across business units. The trade‑off is standardization versus speed. Your choice should reflect your cloud maturity, regulatory obligations, and team capabilities. Capital One started with a centralized model, then evolved to a federated one—empowering teams while keeping guardrails. Tools like AWS Control Tower, AWS Organizations, AWS Config, and AWS Service Catalog help enable either path.
Multi-Region vs. Single Region (Multi-AZ) Deployments
When building for resilience, you’ll choose between multi‑Availability Zones (Multi‑AZ) in one region or a multi‑region design. This comes up in disaster recovery planning. Multi‑region offers maximum redundancy and uptime but costs more and adds complexity. Multi‑AZ is simpler, cost‑effective, and great for single‑geography needs, but it still has a single regional point of failure. Use your RTO (recovery time) and RPO (data loss tolerance) targets to guide the choice. HK01 runs its apps in Hong Kong using Multi‑AZ. AWS services Amazon Route 53, Amazon CloudFront, Amazon S3 Cross-Region Replication (CRR), and AWS Global Accelerator help build resilient multi‑region systems.
Insource Cloud Expertise vs. Outsource to Partners
When moving to the cloud, organizations must choose whether to build in-house cloud expertise or partner with external service providers. This decision typically arises during initial migration planning or when scaling cloud programs across the enterprise. The trade-off is between long-term control and talent development versus speed, scalability, and specialized knowledge. The right choice depends on urgency, skills availability, and your desire to own cloud as a core competency. Many organizations start with partners to accelerate transformation as they do not have the right skills to start with, then insource for sustainability. Thomson Reuters improved efficiency by using AWS Professional Services and AWS Managed Services (AMS) to manage and operate infrastructure while focusing on delivering business value.
Cloud-Native vs. Cloud-Agnostic
When modernizing or building new apps, you’ll face an important choice: build cloud‑native—designing applications to fully leverage the scalability, elasticity, and managed services of the cloud—or aim for cloud‑agnostic, keeping your apps portable across platforms. Cloud‑native applications use patterns like microservices, containers, and serverless to maximize cloud benefits and accelerate innovation. While this can increase your reliance on a specific provider’s ecosystem, it also unlocks speed, efficiency, and deeper integration. Cloud‑agnostic designs preserve flexibility by minimizing provider‑specific dependencies, but often at the cost of added complexity and slower progress. The right choice depends on your business goals: prioritize cloud‑native if speed and innovation are critical or lean toward cloud‑agnostic if flexibility matters more. Vanguard refactored their business capabilities using cloud-native microservices-based architecture on AWS. AWS also offers several solutions to support hybrid and multi‑cloud strategies.
Pay-per-use vs. Reserved capacity vs. Spot Instances
One of cloud’s key benefits is elasticity—but choosing the right pricing model for cloud resources is crucial for FinOps success as your cloud usage matures. Understanding workload patterns helps create a decision tree: use On-Demand for variable workloads, Savings Plans and Reserved Instances for steady predictable usage (multi-year commitments), and Spot Instances for interruptible workloads needing 90% savings. The strategy depends on workload characteristics, reliability requirements, and cost optimization goals. For example, GE Vernova projected $200k yearly savings by using Amazon EC2 Reserved Instances for their compute workloads. AWS pricing models and tools such as AWS Cost Explorer and AWS Compute Optimizer help you figure out the right mix.
Managed Services vs. Self-Managed Services vs. SaaS solutions
As you modernize in the cloud, you’ll often choose between Software as a Service (SaaS), fully managed services, or self-managed infrastructure. This decision affects control, cost, speed, complexity, and crucially, granularity of control and access to data. SaaS (like Salesforce) is fastest but least flexible and offers limited data access. Managed services (such as Amazon Relational Database Service (Amazon RDS)) strike a balance—AWS handles operations while providing more data control. Self-managed gives full control and data access but demands expertise. Base your choice on your team’s skills, need for speed, customization requirements, and critically, your data governance and analytics needs. Airbnb, for example, moved to Amazon RDS to offload backups and scaling, freeing their team to focus on innovation.
Single Cloud vs. Multi-Cloud
When defining your cloud strategy, you’ll need to choose between consolidating all your workloads with one cloud provider (single cloud) or distribute across many (multi-cloud). This often comes up during enterprise architecture planning or post‑M&A (Mergers and Acquisitions). The trade‑off: single‑cloud offers simplicity, deep integration, and faster innovation; multi‑cloud gives flexibility, regulatory coverage, and negotiating leverage—but adds complexity. Many enterprises overestimate the benefits of multi-cloud and underestimate the complexity—especially around skills, security, and operations. The key is to align your cloud strategy to business outcomes, not hypothetical fears or cloud provider lock‑in. NASDAQ embraced AWS to modernize its trading platforms.
Standardized Tech Stack vs. Freedom of Choice
As your cloud program scales across teams, you’ll face a cultural and architectural decision: enforce a standardized tech stack for consistency and governance or allow teams freedom of choice to innovate with their own tools. Unlimited freedom, like multi-cloud, often leads to complexity, higher costs, and fragmented expertise. The trade-off isn’t between innovation and control—it’s about enabling innovation within guardrails. AWS services like AWS Control Tower, AWS Service Catalog, and AWS Organizations help you enforce guardrails while still giving teams room to innovate. Teams get freedom within a framework, avoiding the “zoo” of technologies that increase security risks and operational overhead. Bristol Myers used AWS Control Tower and Service Catalog to implement a self-service cloud platform with automated guardrails.
Final Thoughts
Cloud adoption is as much about making smart decisions as it is about technology. Each choice—whether to rehost or refactor, standardize or decentralize, go single or multi‑cloud—shapes how fast you can innovate and how much value you realize. There’s rarely a perfect answer; what matters is aligning decisions to business outcomes, making them at the right time, and committing once chosen. The cloud rewards speed, experimentation, and continuous improvement—so start with clear priorities, use the right data and tools, and don’t let indecision slow you down. The best strategy is to decide, learn, and adapt.
Additional Reading
Cloud-Native or Lift-and-Shift?
Proven Practices for Developing a Multicloud Strategy
Adopt cloud-native, managed services wherever possible and practical
What’s the Difference Between On-Demand Instances and Reserved Instances?
Maximize Cloud Adoption Benefits with a Well-Architected Organizational Culture