aws migration · the 2026 complete guide

An AWS migration, end to end — the 7 Rs, the MAP funding, the tools, and the honest timeline.

This is the cornerstone guide to migrating to AWS in 2026: the 7 Rs framework for deciding what to do with each workload, the three-phase MAP model AWS runs the migration through, the actual tooling (MGN, DMS, SCT, Migration Hub), realistic timelines and cost — and how the AWS Migration Acceleration Program funds the work so qualifying migrations land at little-to-no cost. CloudRoute routes you to a vetted partner who runs it.

decision framework
7 Rs
MAP phases
Assess · Mobilize · Migrate
typical rehost
8–16 wks
cost (MAP-qualifying)
low / $0
TL;DR
  • An AWS migration is the planned move of applications, data, and infrastructure from a source environment (Heroku, GCP, Azure, on-prem, Oracle, SAP) onto AWS. You decide each workload's fate with the 7 Rs — Retire, Retain, Rehost, Relocate, Repurchase, Replatform, Refactor — then execute. Most teams rehost or replatform the bulk first and refactor selectively afterward.
  • AWS runs serious migrations through the Migration Acceleration Program (MAP): a three-phase model — Assess (TCO + readiness, usually free), Mobilize (landing zone + pilot), Migrate & Modernize (production cutover). AWS funds it with credits scaled to migration size and a post-migration spend commitment. The partner is paid through MAP, so a qualifying migration runs at little-to-no cost to you.
  • CloudRoute routes you to a vetted AWS partner who runs the migration and files the MAP funding — you don't manage MGN agents or write SCT conversion rules yourself. For migrations that don't clear the MAP threshold, it's still a vetted-partner referral that de-risks the cutover. Either way, you get a senior team and a rollback plan.
definition

IWhat an AWS migration actually involves

An AWS migration is the deliberate move of your applications, data, and supporting infrastructure from a source environment onto AWS — done as a planned program, not an ad-hoc rebuild. The hard part is rarely the compute; it's the data, the dependencies, and the cutover.

Most teams arrive here for one of a few reasons: a Heroku or DigitalOcean bill that no longer scales economically, an Azure or GCP commitment expiring, an aging on-prem datacenter or a colo lease coming due, an Oracle licensing renewal that suddenly costs more than the migration would, or a board mandate to consolidate on a single cloud. The trigger is usually commercial; the work is always technical.

A real migration touches five layers. Compute — where your app servers, containers, and functions run. Data — databases, object storage, file shares, and the replication that keeps them in sync until cutover. Networking — VPC design, DNS, load balancers, VPN or Direct Connect back to anything you keep. Identity and security — IAM, secrets, encryption, and the guardrails that stop the new account from becoming a liability. And operations — observability, CI/CD, backups, and the runbook the on-call team uses at 2am.

The single biggest predictor of a smooth migration is how well you understand the existing system before you touch it. A discovery pass — what runs where, what talks to what, how much data moves, what the real RPO/RTO requirements are — is what separates a 10-week rehost from a 9-month archaeology project. AWS Application Discovery Service and Migration Hub exist precisely to make that inventory honest.

This guide is the map for the whole journey. The 7 Rs tell you what to do with each workload. The MAP model tells you how AWS structures and funds the program. The tooling section names the services that do the actual moving. Then we cover timeline, cost, source platforms, risk, and how to start — with links down into the focused pages for each.

the decision framework

IIThe 7 Rs — deciding what to do with each workload

You do not migrate "the system." You migrate a portfolio of workloads, and each one gets a disposition. The 7 Rs are AWS's canonical framework for that decision. Run every application through them during Assess, and you have a migration plan.

The 7 Rs are not a ladder you climb — they are seven distinct dispositions, and a good plan mixes them. The instinct of mature teams is to rehost or replatform the bulk to get off the old bill fast, then refactor the few workloads where the cloud-native payoff is real. Refactoring everything up front is the most common way migrations blow their timeline and budget.

Retire — turn it off

Discovery almost always finds workloads nobody uses: a reporting service replaced two years ago, a staging environment for a dead product, a cron job whose output goes nowhere. You don't migrate these — you decommission them. It's common to retire 10–20% of a server estate, and every retired workload is migration cost you never pay.

Retain — leave it where it is (for now)

Some workloads aren't ready or aren't worth moving yet: a mainframe mid-amortization, an app with a hard data-residency constraint, or something pending its own replacement. You explicitly retain these and plan the hybrid connectivity (VPN or Direct Connect) to bridge them. Retain is a decision, not a default — undocumented "we'll deal with it later" workloads are how migrations stall.

Rehost — lift-and-shift

Move the workload to AWS with minimal change, typically with AWS Application Migration Service (MGN) replicating the whole server into EC2. This is the fastest disposition and the lowest-risk for getting off the source platform. You don't get cloud-native benefits immediately, but you stop the bleeding and buy time to optimize afterward. Most migrations are majority-rehost by server count.

Relocate — move the container/VM layer wholesale

For VMware estates, relocate moves vSphere VMs to VMware Cloud on AWS without converting them — same hypervisor, now on AWS hardware. For containers, it's lifting a cluster to EKS with minimal manifest changes. Relocate is rehost's cousin for environments that are already virtualized or containerized and just need to change address.

Repurchase — drop the app, buy the SaaS

Sometimes the right move is to stop running the software at all: replace a self-hosted CRM, ticketing system, or analytics stack with a SaaS equivalent (often bought through AWS Marketplace). You migrate the data out and retire the servers. Repurchase trades operational burden for a subscription — usually correct for commodity, non-differentiating workloads.

Replatform — lift-tinker-shift

Move to AWS while swapping the undifferentiated heavy lifting for a managed service: self-managed Postgres becomes Amazon RDS or Aurora; a hand-rolled queue becomes SQS; a container on a VM becomes ECS Fargate or App Runner. The app code barely changes, but you shed patching, backups, and failover. Replatform is the sweet spot for databases and stateful middleware — the operational savings are immediate and the risk is contained.

Refactor — re-architect for cloud-native

Re-architect the workload to take real advantage of AWS — decompose a monolith into services on Lambda and EKS, move to event-driven patterns, adopt purpose-built databases. Refactor delivers the biggest long-term payoff (scale, cost, velocity) and carries the biggest cost and risk. The discipline is to refactor selectively, post-migration, on the workloads where the business case is clear — not as a precondition to getting off the old platform.

the practical default

Rehost or replatform the portfolio to exit the source platform on a predictable timeline, then refactor the 10–20% of workloads where cloud-native economics justify it. Trying to refactor everything during the migration is the number-one cause of blown budgets and slipped cutover dates. See lift-and-shift vs replatform for the per-workload decision in depth.

how AWS structures it

IIIThe MAP three-phase model: Assess → Mobilize → Migrate

The Migration Acceleration Program (MAP) is the methodology and funding vehicle AWS uses to run partner-led migrations. It breaks the program into three phases, each with its own deliverables, gate, and funding mechanics. Understanding the phases tells you what happens when — and where the money enters.

MAP is not a tool; it's a structured program AWS partners deliver against, with funding attached at each phase. A vetted partner files the MAP engagement through the AWS Partner Network, runs the phases, and draws the AWS funding — which is why a qualifying migration costs you little-to-nothing. The three phases run in order, with a go/no-go gate between each.

Phase 1 — Assess (usually free)

A 2–4 week discovery and business-case exercise. The partner inventories your estate (often with Application Discovery Service and Migration Hub), builds a total-cost-of-ownership comparison of staying put vs running on AWS, sizes the migration, and assigns a 7 Rs disposition to every workload. The deliverable is a directional TCO, a target-state architecture sketch, and a migration plan. AWS frequently funds the Assess phase entirely, so this stage is typically free to you. See aws migration assessment for what a real Assess engagement produces.

Phase 2 — Mobilize (build the foundation + pilot)

A 4–8 week phase that builds the operational foundation and de-risks the plan with a pilot. The partner stands up the AWS landing zone (multi-account structure, networking, security guardrails, logging, IAM), sets up the migration tooling, and migrates a small, representative set of workloads end-to-end to prove the runbook. AWS provides Mobilize-phase funding — commonly credits in the range of a quarter of the projected migration cost — to offset the build. The landing zone you stand up here is the foundation everything else lands on; get it right and the rest is repeatable.

Phase 3 — Migrate & Modernize (production)

The production phase: migrate the bulk of the portfolio in waves, cut over, validate, decommission the source, and modernize selectively. This is where most of the calendar lives — anywhere from 8 weeks to 9+ months depending on estate size and how much refactoring is in scope. AWS funding at this phase is larger (commonly scaling toward half of eligible migration cost), credited against your AWS bill as workloads land. By the end you're running on AWS, the old environment is off, and the post-migration spend commitment that justified the MAP funding kicks in.

the funding mechanism

IVHow MAP funds the migration toward $0 — honestly

This is the part most "how to migrate to AWS" guides skip. AWS has a direct commercial incentive to move your workloads onto its platform, and it puts real money behind that through MAP. Here's how the economics actually work — and where the honest caveats are.

The mechanism: AWS wants your long-term consumption, so it co-invests in the cost of getting you there. Through MAP, AWS provides credits scaled to the size of the migration — funding the Assess phase, offsetting the Mobilize build, and crediting a meaningful share of the Migrate-phase cost. The partner doing the work is compensated through MAP funding as well. Stack those together and a qualifying migration can land at little-to-no net cost to you.

The honest framing — because overclaiming here destroys trust: MAP funding scales with migration size and is tied to a post-migration AWS-spend commitment. It's designed for migrations of real substance, not a single small app. If your migration clears the threshold, the funding genuinely makes it low-cost or effectively free to execute. If it doesn't, MAP isn't the right vehicle — but a vetted partner referral still de-risks the cutover, and smaller AWS credit programs may apply instead.

MAP also ties directly into the broader AWS credit picture. The same partner-attested, AWS-funded mechanics that drive credit programs drive MAP — they're two faces of the same incentive. If your situation is part-migration, part-greenfield, the credit and migration funding can be sequenced together. See the credits cluster for the funding mechanics in depth: the $100K AWS credits guide and how AWS POC funding works explain the partner-filed model that MAP shares.

CloudRoute's role is the routing: we connect you to a partner who both runs the migration and files the MAP engagement, so the funding actually gets claimed. Founders routinely leave AWS funding on the table simply because nobody filed for it — a partner who knows the program closes that gap. See the AWS Migration Acceleration Program page and AWS migration funding for the full mechanics.

what “low / $0” really means

For a migration that qualifies for MAP, AWS-funded credits plus partner compensation can cover effectively all of the migration cost — you commit to running the resulting workloads on AWS afterward. For migrations below the MAP threshold, treat CloudRoute as a vetted-partner referral that de-risks the cutover, not a free-migration guarantee. We tell you which bucket you're in before you commit anything.

the tools that do the work

VThe AWS migration toolchain

A migration is executed with a specific set of AWS services, each owning a slice of the move. You don't need to operate these yourself when a partner runs the migration — but knowing what does what makes you a far better-informed buyer.

The toolchain splits cleanly along the layers from Section I: discovery, server/compute migration, database migration, and data transfer — coordinated by a control plane.

  • AWS Application Migration Service (MGN) — The default rehost engine. A lightweight agent on each source server continuously replicates it into AWS; at cutover you boot the converted instance in EC2 with minimal downtime. This is how lift-and-shift actually happens at scale. See aws application migration service.
  • AWS Database Migration Service (DMS) — Migrates databases with continuous replication so the source stays live until cutover. Handles homogeneous moves (Postgres→Postgres) trivially and heterogeneous moves (Oracle→Aurora PostgreSQL) in tandem with SCT. See aws database migration service.
  • AWS Schema Conversion Tool (SCT) — Converts schema, stored procedures, and application SQL between different database engines. The heterogeneous-migration workhorse — and the part that takes real effort, because not everything converts automatically. SCT produces an assessment report flagging what needs manual rework.
  • AWS Migration Hub — The control plane: a single console to track every workload's status across all the tools and migration waves. For a multi-wave program with hundreds of servers, this is where the program manager lives.
  • AWS Application Discovery Service — Builds the pre-migration inventory — what servers exist, their utilization, and the network dependencies between them. The data that makes the 7 Rs decisions honest and the Assess TCO credible.
  • AWS DataSync & Transfer Family — Bulk data movers. DataSync shifts large file shares and object data into S3/EFS/FSx over the network; Transfer Family handles SFTP/FTPS workflows. For petabyte-scale or low-bandwidth sites, the Snow family ships physical appliances.

The pattern in practice: Discovery Service builds the inventory, Migration Hub tracks the program, MGN handles the rehosts, DMS + SCT handle the databases, and DataSync moves the bulk data. A partner orchestrates all of it against the runbook proven during Mobilize — so the production waves are repetition, not improvisation.

where you're coming from

VISource platforms — what moves where

The right target architecture depends heavily on where you're starting. Each source platform has well-trodden mappings onto AWS services. Here are the common ones, with links to the dedicated guide for each.

Across all of these, the same shape holds: compute maps to a container or serverless service, the database replatforms onto RDS or Aurora, and object/file storage moves to S3. The detail — and the difficulty — is almost always in the data layer.

PaaS — Heroku, DigitalOcean, Vercel

Heroku dynos map to ECS Fargate or App Runner; Heroku Postgres replatforms onto RDS or Aurora; add-ons map to native AWS services. DigitalOcean Droplets and App Platform follow the same path. Vercel front-ends often stay on Vercel while the backend and data move to AWS, or move wholesale to Amplify/CloudFront + Lambda. These are typically the fastest migrations — small estates, clean boundaries. See heroku to aws.

Other clouds — GCP and Azure

GCP: GKE→EKS, Cloud SQL→RDS, BigQuery→Redshift or Athena, GCS→S3. Azure: AKS→EKS, Azure SQL→RDS, Functions→Lambda, App Service→App Runner, Blob Storage→S3. Cloud-to-cloud moves are mostly replatform exercises — the concepts map almost one-to-one, and egress cost plus data-sync time are the main planning variables.

On-premise and VMware

Physical servers rehost via MGN into EC2. VMware estates can relocate wholesale to VMware Cloud on AWS, or run on AWS Outposts for workloads that must stay physically local. On-prem migrations lean hardest on discovery (the inventory is rarely accurate) and on hybrid networking via Direct Connect during the transition. See on-premise to aws.

Commercial databases and packaged apps — Oracle, SQL Server, SAP

Oracle→Aurora PostgreSQL (via SCT + DMS) is one of the highest-ROI moves there is — Aurora's performance with none of Oracle's license cost — but it's also the most schema-conversion-heavy. SQL Server can rehost, replatform to RDS, or convert to Aurora. SAP runs as a certified workload on AWS with its own reference architectures. These are the migrations where partner expertise pays for itself many times over. See oracle to aurora and sql server to aws.

how long, how much

VIITimeline and cost — realistic ranges

Every migration is different, but the ranges are knowable. Here's what to actually expect on calendar and budget — before MAP funding offsets the cost.

Timeline is driven by estate size, data volume, and how much refactoring is in scope — not by the cloud itself. A clean PaaS migration (a handful of services, one or two databases) often completes inside the MAP Assess + Mobilize window. A mid-size estate (50–200 servers, several databases) is typically a 4–8 month program. A large or heavily regulated enterprise estate, or one with deep heterogeneous-database conversion, runs 9–18 months and several waves.

Cost has two components people conflate: the one-time migration cost (the project — discovery, landing zone, execution, the partner's time) and the ongoing AWS run-rate after you land. MAP is designed to offset the first; the second is what your TCO analysis in Assess is really about, and it's usually lower than the source platform once rightsizing and reserved/savings-plan pricing are applied. See aws migration cost and aws migration timeline for the detailed models.

The key planning numbers: budget 2–4 weeks for Assess, 4–8 weeks for Mobilize, and size Migrate by waves of workloads rather than as one monolith. Downtime per workload at cutover, with MGN and DMS continuous replication, is typically minutes-to-hours — not days — because the heavy data movement happens live before the switch.

the honest part

VIIIRisks, downtime, and rollback

A credible migration plan names its failure modes up front and has an answer for each. These are the risks that actually bite, and how a competent partner contains them.

  • Cutover downtime — The window where the source goes read-only and the target takes over. Continuous replication (MGN/DMS) shrinks this to minutes-to-hours per workload by moving the bulk of the data ahead of time. The risk is underestimating the final delta-sync and validation time — which is exactly what the Mobilize pilot exists to measure.
  • Data-sync and consistency risk — The hardest problem in any migration: making sure the target data is complete and correct at the cutover instant, with no lost writes. Mitigated with replication validation, reconciliation checks, and a defined point-in-time cutover — not a hopeful copy-and-pray.
  • Heterogeneous schema conversion — Oracle→Aurora and SQL Server→Postgres conversions never fully automate. SCT flags the stored procedures, data types, and SQL that need manual rework; underestimating that backlog is a classic timeline killer. The Assess report should quantify it before you commit a date.
  • Hidden application coupling — Discovery routinely surfaces undocumented dependencies — the service that quietly calls a database it shouldn't, the hardcoded IP, the shared file mount. Application Discovery Service maps these so they don't detonate mid-cutover. Skipping discovery is how migrations find these the hard way.
  • No rollback plan — The non-negotiable. Until cutover is validated and stable, the source environment stays running and reversible — replication can be reversed or the DNS pointed back. A migration without a rehearsed rollback is a gamble; a wave-based plan with a rollback at each gate is an engineering project. Every CloudRoute-routed migration ships with one.
the decision framework, side by side

The 7 Rs — what each disposition means, and when to pick it

Run every workload in your estate through this table during the Assess phase. The output is your migration plan: a disposition, an effort level, and a tool for each application.

RWhat it meansEffortRiskAWS toolingPick it when…
RetireDecommission — nobody uses itNoneNoneDiscovery shows it's dead or redundant (often 10–20% of an estate)
RetainLeave on the source, bridge with hybrid networkingLowLowDirect Connect / VPNNot ready, data-residency-bound, or pending its own replacement
RehostLift-and-shift, minimal changeLowLowMGN → EC2You need off the source platform fast; optimize later
RelocateMove the VM/container layer wholesaleLowLowVMware Cloud on AWS / EKSAlready virtualized or containerized; just change address
RepurchaseDrop the app, buy a SaaS equivalentMediumMediumAWS Marketplace + data exportCommodity, non-differentiating workload (CRM, ticketing)
ReplatformLift-tinker-shift onto managed servicesMediumMediumRDS / Aurora / ECS / App RunnerYou want to shed ops (patching, backups) without rewriting
RefactorRe-architect for cloud-nativeHighHighLambda / EKS / purpose-built DBsClear business case for scale/cost/velocity — do it selectively, post-migration
The mature pattern: rehost/replatform the portfolio to exit the source on a predictable timeline, refactor the 10–20% where cloud-native economics justify it. Refactoring everything up front is the top cause of blown migrations. See lift-and-shift vs replatform for the per-workload call.
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A Heroku-and-on-prem migration, MAP-funded — anonymized

inquiry · series-b b2b saas, Austin
Series-B B2B SaaS, ~70 engineers. Core app on Heroku (≈40 dynos, Heroku Postgres at ~600GB) plus a self-managed analytics + reporting stack in a leased datacenter. Heroku bill ≈$31K/month and climbing; colo lease up for renewal.

Situation: Heroku economics had stopped scaling and the datacenter lease forced a decision. They wanted one cloud, lower run-rate, and SOC 2-grade controls — but the platform team was fully allocated to product and couldn't run a migration of this size without stalling the roadmap. They also didn't know AWS would fund the move.

What CloudRoute did: Routed within 24 hours to an Advanced-tier AWS partner with Heroku + data-center migration track record. Partner ran a free MAP Assess (3 weeks): 7 Rs disposition across ~120 workloads — retire 18, rehost the datacenter servers via MGN, replatform the Heroku app to ECS Fargate, Heroku Postgres → Aurora PostgreSQL via DMS. Mobilize (6 weeks) stood up the landing zone + pilot. Migrate ran in four waves over ~5 months. Partner filed the MAP engagement so AWS funding offset the work.

Outcome: Cutover downtime per wave: 20–90 minutes (DMS continuous replication carried the data ahead of each switch). Steady-state AWS run-rate landed ~38% below the combined Heroku + colo spend after rightsizing and a savings plan. MAP funding plus partner compensation covered effectively all of the one-time migration cost; the customer's net outlay was near $0, against a post-migration AWS-spend commitment. Total program: ~8 months, founder/platform-lead time ≈ a few hours a week.

estate: ~120 workloads · program: ~8 months · run-rate cut: ~38% · migration cost to customer: ≈$0 (MAP-funded)

faq

Common questions

What is an AWS migration, in one sentence?
It's the planned move of your applications, data, and infrastructure from a source environment (Heroku, GCP, Azure, on-prem, Oracle, SAP, etc.) onto AWS — executed as a structured program where each workload gets a 7 Rs disposition (Retire, Retain, Rehost, Relocate, Repurchase, Replatform, or Refactor) and is migrated with AWS tooling like MGN and DMS.
How long does an AWS migration take?
It depends on estate size and refactoring scope, not on AWS itself. A clean PaaS migration (a few services, one or two databases) can finish inside the MAP Assess + Mobilize window. A mid-size estate (50–200 servers) is typically a 4–8 month program. A large or heavily regulated estate, or one with deep heterogeneous-database conversion, runs 9–18 months across several waves. Plan 2–4 weeks for Assess and 4–8 weeks for Mobilize regardless of size.
How does AWS MAP funding make a migration low-cost or free?
Through the Migration Acceleration Program, AWS co-invests in moving you to its platform: it funds the Assess phase, offsets the Mobilize build, and credits a meaningful share of the Migrate-phase cost — and the partner running the work is compensated through MAP as well. For a qualifying migration, those combine to cover effectively all of the one-time migration cost, in exchange for a post-migration AWS-spend commitment. Honest caveat: MAP scales with migration size; below the threshold it isn't the right vehicle, though a vetted-partner referral still de-risks the cutover.
What are the three MAP phases?
Assess (2–4 weeks: discovery, TCO business case, 7 Rs plan — usually AWS-funded, so free to you), Mobilize (4–8 weeks: build the AWS landing zone, set up tooling, run a pilot to prove the runbook), and Migrate & Modernize (the production phase: migrate the portfolio in waves, cut over, decommission the source, modernize selectively). Each phase has a go/no-go gate and its own AWS funding.
Which AWS tools are used to actually move workloads?
Application Migration Service (MGN) for rehosting servers into EC2; Database Migration Service (DMS) for live database migration; Schema Conversion Tool (SCT) for heterogeneous database conversions (e.g. Oracle→Aurora); Migration Hub as the program control plane; Application Discovery Service for the pre-migration inventory; and DataSync / Transfer Family (and the Snow family) for bulk data movement. A partner orchestrates these so you don't operate them yourself.
What's the difference between lift-and-shift and replatforming?
Lift-and-shift (Rehost) moves a workload to AWS with minimal change — fastest and lowest-risk, usually via MGN into EC2, with optimization deferred. Replatform (lift-tinker-shift) moves it while swapping undifferentiated heavy lifting for a managed service — e.g. self-managed Postgres becomes Amazon RDS/Aurora — so you shed ops without rewriting the app. Most migrations rehost or replatform the bulk and refactor only where the cloud-native payoff is clear.
How much downtime does cutover require?
Typically minutes-to-hours per workload, not days. MGN and DMS replicate the source continuously, so the bulk of the data has already moved before the switch — cutover is a short read-only window for the final delta-sync and validation. The Mobilize-phase pilot measures the real window for your workloads so the production cutovers are predictable.
Do I have to run the migration myself, or does CloudRoute do it?
CloudRoute doesn't run migrations — we route you to a vetted AWS partner who does, and who files the MAP engagement so AWS funding gets claimed. You don't manage MGN agents or write SCT conversion rules; the partner runs the program against a proven runbook with a rollback plan at every gate. For migrations that qualify, MAP funds it toward $0; for smaller ones, it's still a vetted referral that de-risks the cutover. Start at /for/migration.

Planning an AWS migration? Get it run for you — and funded.

CloudRoute routes you to a vetted AWS partner who runs the migration end to end and files the MAP funding. Qualifying migrations land at little-to-no cost. No discovery theater, no procurement maze.

free MAP assessmentAssess phase
cost (MAP-qualifying)low / $0
rollback planevery gate
AWS Migration: the 7 Rs, MAP funding & tools (2026 guide) · CloudRoute