Cloud Migration Checklist: Step-by-Step Guide for a Smooth Migration

Dec 12, 2025

Cloud migration is one of the most consequential technical and organizational projects an enterprise undertakes. Done well, it reduces TCO, accelerates delivery, improves resilience, and unlocks cloud-native capabilities (analytics, AI, serverless). Done poorly, it delivers ballooning costs, outages, compliance violations, and months of rework.

This guide is a deep, expert-level cloud migration checklist and playbook you can apply to any cloud provider or hybrid strategy. It covers strategy and planning, an in-depth pre-migration inventory, technical migration patterns, testing and rollback plans, security and compliance controls, operational handover, and post-migration optimization. Use it as a template, adapt the checkpoints to your scale, and turn migration risk into predictable outcomes.

Executive summary of Cloud Migration Checklist: migration goals & outcomes

Before any technical work, answer these questions and document them:

Why are we migrating? (cost reduction, resilience, agility, end-of-life hardware, M&A consolidation, regulatory reasons)
What are our success criteria? (cost targets, uptime/SLA, time-to-market improvements)
What’s the timeline and budget? (milestones, contingency)
Which migration pattern will we favor? (lift-and-shift vs refactor)
What’s the minimum viable migration (MVM) scope for early value?

These decisions form the cloud transition plan and shape downstream choices (architectural, organizational, contractual)

Migration strategies: the 5 R’s (plus two)

Classic migration options are chosen per application:

Rehost (Lift & Shift): move VM to cloud with minimal changes. Fast, low immediate engineering effort, but may not realize cloud economics without later optimization.
Replatform (Lift, Tweak & Shift): small optimizations (e.g., managed DB instead of self-managed). Reduces ops overhead and starts cloud benefits.
Refactor / Re-architect: rewrite to cloud-native (microservices, serverless). Higher cost/risk, but the largest long-term value.
Replace (SaaS): swap an application for a SaaS offering (CRM → Salesforce, etc.). Fast time-to-value if processes align.
Retain: keep on-prem for regulatory or technical reasons; plan for hybrid ops.
Retire: decommission unused apps discovered during inventory.
Relocate (Containerize): package apps (container + orchestrator) and move to managed Kubernetes.

Recommendation: perform application-by-application analysis and use a mixed strategy. Many organizations combine rehosting for low-risk apps and refactoring for strategic ones.

Project governance, teams & roles

Successful migration with cross-functional governance is non-negotiable.

Core team roles

Executive sponsor: business accountability, funding, escalation.
Program manager / PMO: coordinates timeline, budgets, and vendor relationships.
Cloud architect: defines target architectures and migration patterns.
Security & compliance lead: approves controls and monitors risk.
Infrastructure & platform engineers: implement core cloud components (network, IAM, monitoring).
Application owners/product managers: define acceptance criteria for each app.
Database engineers/data engineers: plan and execute data migrations.
DevOps / Site Reliability Engineers (SRE): build CI/CD, IaC, automation, and runbooks.
FinOps / cost analyst: tracks usage, budgets, and optimization plans.
Change management/training lead: user training, documentation, and operational handover.

Governance bodies

Steering Committee: weekly exec reviews (risks, budgets, compliance).
Architecture Review Board: approves target designs and refactor efforts.
FinOps Council: monthly cost and reservation planning.
Change Advisory Board (CAB): approves major cutovers.

Pre-migration planning checklist (business, financial, technical)

Business & financial

Create business case and ROI model (TCO baseline & projected cloud costs).
Define success KPIs (migration KPIs below).
Secure budget and contingency.
Legal & procurement: review SLAs, data residency clauses, vendor lock-in, and exit terms.

Technical

Select target provider(s), and list required regions.
Define core platform baseline: networking, identity, logging, monitoring, backup/DR.
Choose IaC tooling (Terraform/CloudFormation/ARM/Pulumi).
Define security baseline and compliance matrix.
Define integration/metrics for observability (APM, logging, metrics).
Plan training and skills uplift for teams.

Discovery & assessment: inventory, dependency mapping & prioritization

Discovery is the foundation. It must be exhaustive and machine-driven where possible.

Discovery tasks

Inventory compute, databases, storage, network, load balancers, DNS records, certificates, backups, scheduled jobs, and compute images.
Collect telemetry: CPU, memory, disk I/O, network I/O, storage usage, process lists, and JVM/OS metrics over representative intervals (min 2–4 weeks; prefer 90 days for seasonal apps).
Map application dependencies, both direct (DB, cache) and indirect (message queues, LDAP, file shares). Use automated agents (discovery tools) and run dependency mapping/visualization.
Tag and classify each workload: criticality (P0–P3), business owner, security classification, latency sensitivity, data residency constraints, refactor complexity, and cloud readiness.

Prioritization rubric

Low complexity + noncritical → candidate for early rehost pilot
High business value + cloud-native candidate → plan refactor in parallel
Regulatory constraints → target hybrid or specific region plan

Deliverable: master inventory spreadsheet with fields: app name, owner, current infra, dependencies, estimated migration effort (person-days), recommended migration pattern

Target architecture & design: networking, IAM, data strategy, hybrid/multi-cloud

Design the landing zone and cross-cutting cloud platform before mass migration.

Architecture checklist

Landing zone: organization accounts, subscriptions, or projects; baseline IaC templates to create standardized environments (prod, stage, dev).
Networking: VPC / VNet design, subnets, network ACLs, DNS, transit gateways, peering, VPN/Direct Connect/ExpressRoute equivalents. Latency and egress cost modeling.
Identity & Access Management (IAM): centralized identity with least privilege (SAML/SSO, MFA), role mapping, service principals, key rotation. Decide on federated identity vs cloud native.
Data strategy: master data locations, hot/warm/cold tiers, data residency, encryption (at rest/in transit), key management (use managed KMS or customer-managed keys), and backup/DR plans.
Security posture: baseline controls (CIS benchmarks), endpoint management, container runtime security, WAF, DDoS protection, secrets management.
Monitoring & observability: centralized logging, tracing, metrics, alerting thresholds, and runbooks.
Cost/FinOps: tagging schema, billing export, budget alerts, and reservation strategy.
Compliance controls: audit logging, retention policies, e-discovery readiness.

Deliverable: target architecture diagrams, landing zone IaC, and a requirements matrix mapping apps to cloud services.

Migration approaches & tools

Choose tools matched to the approach and data volume. Examples (vendor-agnostic and known tools):

Rehost/lift & shift

VM replication/image export → import into cloud images. Tools: cloud provider migration services (e.g., AWS Server Migration Service, Azure Migrate, GCP Migrate), third-party (CloudEndure, Velostrata/Migrate for Compute Engine historically).

Replatform

Move to managed services (RDS, Cloud SQL, managed caches). Tools: schema migration tools (DMS, Database Migration Service), containerization platforms.

Refactor / re-architect

Containerize and deploy to Kubernetes/managed clusters (EKS, AKS, GKE). Tools: Docker, build pipelines, Helm charts.
Break monoliths into microservices and adopt serverless functions where appropriate.

Data migrations

Online replication with change data capture (CDC), bulk transfer (storage services like Snowball/Transfer Appliance), database migration services, or ETL pipelines.

Hybrid / Network

VPN/Direct Connect/ExpressRoute, and transit network services. Tools: SD-WAN, network appliances, and managed VPN.

Automation & IaC

Terraform, CloudFormation, ARM, Pulumi. CI/CD: Jenkins, GitHub Actions, GitLab, Azure DevOps.

Observability & security

Centralized logging: ELK/EFK, CloudWatch/Log Analytics/Stackdriver (provider equivalents).
Security scanning: SAST/DAST, infrastructure scanning tools, container security (Trivy, Clair), policy enforcement (OPA, Gatekeeper).

Proof of concept (PoC) and pilot guidelines

Run at least one PoC before large migrations.

PoC goals

Validate the landing zone architecture, networking latency, IAM integration, backup/restore, monitoring pipelines, and cost model.
Test a single small but representative application through the full migration path (data migration, cutover, smoke tests).
Measure migration time, data throughput, and performance baselines.

PoC success criteria

App functions correctly in the cloud with expected latency/SLA.
Restore tests succeed within RTO/RPO goals.
Observability, alerts, and dashboards produce actionable outputs.
Cost estimates fall within forecasts.

Duration: 2–6 weeks, depending on complexity.

Data migration planning and techniques

Data is often the riskiest component. Choose the strategy per data size & RTO/RPO:

Small datasets (< few TB)

Bulk transfer (secure copy, object upload) during low traffic windows. Validate checksums.

Large datasets / continuous sync

Initial bulk copy (via physical appliance if necessary), then CDC to sync changes till cutover. Tools: DB-specific replication, provider DMS, or third-party replication. Test final cutover delta window.

Database migration

Evaluate schema compatibility and versioning. If moving from proprietary engines, consider managed equivalents (and license transfer).
For zero-downtime, consider a blue/green approach with a traffic switch once the replication lag is minimal.

File systems & shared storage

If apps rely on POSIX file systems, consider solutions like managed file services or NFS gateways, and test performance and locking semantics.

Deliverable: data migration runbook with pre-copy, CDC setup, cutover window, rollback procedure, and verification checks (row counts, checksums).

Testing, validation & rollback strategies

Testing is where success becomes visible. Build exhaustive plans.

Testing types

Unit and integration tests (CI runs).
Smoke tests after deployment (basic sanity checks).
Functional tests for application behaviors.
Load and performance tests to validate SLAs.
Security tests: vulnerability scans, penetration testing, SCA for dependencies.
Disaster recovery drills: simulate AZ/region failures and test failover.

Rollback patterns

Blue/Green deployment: maintain two identical environments; switch traffic when ready, roll back by routing back to the previous environment.
Canary releases: route a small percentage of traffic to the new deployment; monitor and scale gradually.
Database rollback: ensure backups and rollback scripts exist, but exercise caution; DB rollbacks can be complex. Prefer forward migration with compatibility (backwards compatible schema changes).

Acceptance gates

Define explicit acceptance criteria for cutover (error rate thresholds, latency targets, transaction success rates). Do not proceed until the gates are green.

Cutover & go-live checklist

Prepare an operational day plan and a runbook.

Pre-cutover (24–72 hours)

Final replication sync and quiesce write activity if possible.
Notify stakeholders and support teams.
Back up the current environment and validate backup integrity.
Ensure runbook, rollback steps, and contact lists are ready.

Cutover window

Execute DNS TTL reduction early (shorten TTLs to speed DNS propagation).
Execute final data delta sync and cut read/write traffic to the cloud.
Run smoke tests and then incremental functional checks.
Open monitoring dashboards and runbook channels.

Post-cutover (0–72 hours)

Keep enhanced monitoring and on-call rotations for 72 hours.
Gradually decommission the previous environment only after verifying operations.
Collect post-go-live metrics and immediately address anomalies.

Post-migration checklist: stabilization, optimization, decommissioning

Migration is not complete at cutover; stabilization and optimization follow.

Stabilization

Resolve priority P1–P3 incidents from post-go-live.
Conduct a post-mortem for the migration event (what went well, what didn’t).
Ensure knowledge transfer and update runbooks.

Optimization

Rightsize compute based on cloud utilization telemetry.
Purchase reserved/savings plans for stable workloads.
Implement storage lifecycle policies.
Review network architecture for egress optimizations.

Decommissioning

Plan safe decommission of legacy infrastructure: snapshot export, archival to long-term storage, revoke credentials, terminate VMs and storage, and adjust DNS.
Delete unused resources to stop ghost costs (and verify with billing reports).

Security, compliance & governance checklist

Security must be baked in before migration.

Pre-migration

Define data classification and handling rules.
Approve encryption standards (KMS, HSM, CMKs).
Implement IAM controls and least privilege.
Plan logging & audit trails retention for compliance.
Validate network segmentation and secure connectivity.

During migration

Secure data in transit (TLS) and at rest (provider encryption).
Restrict admin access to migration windows.
Run vulnerability scans and configuration checks before cutover.

Post-migration

Enable continuous posture monitoring (CSPM) and alerting.
Ensure audit logs forward to secure storage with access controls.
Conduct compliance validation (e.g., SOC2, PCI, HIPAA) if required and document evidence.

Cost & performance optimization after migration

Cloud gives flexibility: leverage it to optimize.

Immediate cost controls

Tag everything and reconcile cost allocation to owners.
Identify and stop unused resources and snapshot sprawl.
Rightsize and buy reservations for consistent workloads.

Performance

Reconfigure autoscaling policies based on cloud metrics.
Use CDN and caching to reduce backend load and egress.
Optimize database indexes and use read replicas for scale.

FinOps

Hold monthly FinOps review: analyze spend trends, reservation coverage, and anomaly investigations.
Build cost-per-feature metrics so product owners feel ownership.

KPIs, metrics & reporting (how to measure success)

Define success with measurable KPIs.

Migration project KPIs

% applications migrated vs plan
Mean time to migrate per app (MTTM)
Migration incidents per application (post-migration P1/P2 counts)

Operational KPIs

Uptime/availability (SLA compliance)
Latency and error rate for critical endpoints
RTO / RPO for critical systems

Financial KPIs

Cloud spend vs forecast (monthly)
Cost per business transaction (e.g., cost per order)
% of spend under reservation / committed usage

Security & compliance KPIs

Number of non-compliant findings resolved
Time to remediate security alerts

Common pitfalls and how to avoid them

Incomplete discovery: misses dependencies → outages. Mitigation: automated dependency scanning, application owner interviews, and synthetic tests.
No rollback plan: leads to extended outages. Mitigation: blue/green & canary strategies and tested rollback steps.
Underestimating data migration: data volumes and bandwidth can create unexpectedly long cutover windows. Mitigation: pre-copy + CDC + test runs.
Ignoring cost model: cloud bills surprise stakeholders. Mitigation: FinOps, tagging, and early reservation planning.
Security gaps: misconfigurations cause breaches. Mitigation: baseline compliance templates, CSPM, and security automation.
Single point of knowledge: only one engineer knows the critical steps. Mitigation: cross-team documentation and runbook drills.

90-day sample migration roadmap (template)

Day 0–14 (Plan & Prepare)

Form governance, finalize business case, select pilot app, prepare landing zone IaC.

Week 3–6 (Discovery & PoC)

Full inventory, dependency mapping, pilot migration, and validate PoC success criteria.

Week 7–12 (Pilot to early migration)

Migrate low complexity applications, implement tagging, reserve budgeting, and train ops on runbooks.

Month 4–6 (Scale migrations)

Migrate medium complexity apps, start refactor tracks for strategic apps, and implement FinOps cadence.

Month 7–12 (Stabilize & Optimize)

Complete remaining migrations, decommission legacy hardware, optimize reserved commitments and storage tiers, and conduct post-migration review.

Adjust timelines to the organization’s scale and regulatory windows.

Appendix: templates & checklists

Minimal printable pre-migration checklist (copy as a working sheet)

Business case & sponsor assigned
Inventory & dependency map complete
Landing zone & IAM baseline deployed (IaC)
Network connectivity (VPN/direct link) validated
Data migration plan documented (bulk + CDC)
PoC completed, and acceptance confirmed
Runbook, rollback plan, and escalations documented
Security baseline & compliance checks passed
Monitoring & alerting configured
Cutover schedule and stakeholder notifications are ready

Final words: migrate deliberately, not hurriedly

Cloud migration is more than a technical lift: it’s an organizational transformation. Use the checklist above to turn an unpredictable program into a repeatable factory. Prioritize exhaustive discovery, secure a small successful pilot, automate repeatable work with IaC and CI/CD, and adopt a FinOps culture to keep costs predictable. With these controls, you’ll convert migration risk into measured engineering progress and deliver real business value.