Why the compliance audit is critical immediately after migration Migration to AWS is a pivotal step: once the services are cut over to production, the infrastructure is exposed to real compliance controls, external auditors, and concrete legal responsibilities. At this stage, waiting a few weeks to validate compliance means exposing the company to regulatory risks, audit gaps, and potentially penalties. A post-migration compliance audit is not a deferred administrative exercise: it is an urgent validation of the key points that guarantee your infrastructure meets your industry's standards (GDPR for personal data, PCI-DSS for payments, ISO 27001 for information security, SOC 2 for service operators) and your internal governance policies. In the post-migration phase, the project team is still mobilized and able to act quickly on detected gaps, unlike a late discovery that would require a costly remobilization. It is also the moment when configurations, accesses, and logs are fresh and traceable, allowing a real validation rather than an after-the-fact reconstruction. An audit without delay also avoids letting compliance debt accumulate and having to later justify to your external auditors or your leadership that you were aware of a gap and tolerated it.
Essential regulatory checkpoints depending on your sector Before validating compliance, identify the regulatory frameworks that apply to your activity: GDPR if you process the personal data of European residents (annual audit, documentation, right of access, encryption), PCI-DSS if you store or process bank card data (data isolation, penetration testing, logging), HIPAA if you handle health data (encryption in transit and at rest, access auditing), SOC 2 if you are a service operator or a SaaS (segregation of duties, monitoring, incident response), or specific sector standards (ANSSI for sensitive French data, reinforced GDPR in some countries). As soon as the cutover is complete, go through the applicable regulatory checklist: verify that sensitive data is encrypted (at rest and in transit), that accesses are logged and auditable, that backups are verified and restorable, that network isolations (VPC, security groups) respect the required segmentation. Each framework adds specific requirements: GDPR mandates a processing register, signed subcontracting contracts with AWS (a DPA is available), and compliant data deletion procedures; PCI-DSS requires strict segmentation of the payment network, regular security scans, and secrets management without exposure. Devote the first 48 to 72 hours post-migration to validating these fundamentals: no publicly exposed API keys, no S3 bucket accessible without authentication, no secrets in plaintext in logs or environment variables. This quick phase identifies the critical gaps that must be corrected before declaring the project closed.
Validating governance and access policies Regulatory compliance is not limited to external requirements: it also includes your internal governance policies. After the migration, validate that the principles of least access and separation of roles are respected. This means: verify that AWS IAM roles are configured according to the principle of least privilege (each role has only the permissions strictly necessary to its function), that secrets (passwords, API keys, certificates) are stored in a secure manager (AWS Secrets Manager or Parameter Store) and not hardcoded in Docker images or config files, that cross-account access or access to critical resources goes through multi-factor authentication (MFA), that AWS administrators can be audited (logging of their actions via CloudTrail), and that sensitive data is never accessible without encryption or without passing through a control proxy. Also ask: who can create AWS resources? Who can modify the configuration? Who can delete resources? The answers must be traceable and limited. If you had a security or compliance lead in your migration team, this is the moment to have them audit these configurations directly in the AWS console or via automated scans (for example, AWS Config, Prowler, CloudMapper). Create a register of granted accesses and critical resources: it will serve for future audits and will let you quickly identify anomalies or unused accounts.
Verifying traceability and logging for audits No audit can be conclusive without reliable logs. During the migration, logs were often enabled in passing but not tested; right afterward, you must validate that they are properly captured, centralized, and queryable. Enable or verify CloudTrail (which records all AWS API calls), CloudWatch Logs (for application and system logs), and VPC Flow Logs (for network visibility). Make sure that: logs cannot be deleted by an unauthorized user (log immutability), logs are encrypted and access to the encryption key is restricted, logs are centralized in a dedicated AWS account or a third-party service (SIEM) so that a compromise of a production account cannot delete the evidence of an intrusion, and log retention respects legal obligations (for example, GDPR often requires 6 months to 1 year for access logs). Test it concretely: launch an action (create a resource, modify a policy, log in) and verify that the event appears in CloudTrail in under a minute. Also test that logs do not leak: a log should never contain passwords or tokens in plaintext. Configure alerts on sensitive events (creation of a new IAM user, deletion of a resource, modification of a security policy) so that you are quickly warned of an anomaly. This logging infrastructure is your safety net: it will let you demonstrate to an auditor that you tracked who did what and when, essential to pass any external audit.
Data encryption, backup integrity, and recovery plan Two fundamental pillars of post-migration compliance: encryption of sensitive data and the ability to recover after a disaster. For encryption, validate that data at rest (RDS databases, S3 buckets, EBS volumes) uses the encryption provided by AWS (AWS-managed or customer-managed keys via KMS). Data in transit (between your applications, toward the internet) must go through TLS 1.2 minimum. Do not leave a single database table unencrypted if it contains sensitive data. For backups, verify that: EBS snapshots and RDS backups are regular (at least daily for critical data), backups are encrypted, backups are tested (at least one test restore from each important backup), and backups are isolated in a remote AWS account or even out of region so that a massive accidental deletion cannot destroy the copies. Test the disaster recovery plan: simulate a database loss and measure the recovery time from a backup (RTO, Recovery Time Objective). Also measure the tolerable data loss (RPO, Recovery Point Objective) and verify that your backups respect it. These tests often reveal problems: an RDS snapshot that takes 6 hours to restore, an incomplete recovery procedure, or a forgotten backup encryption. Right after the migration is the right time to correct these gaps before they become normative.
Remediation process and closing the compliance audit An audit does not end when you discover a gap: it ends when the gap is corrected, validated, and documented. After the initial post-migration validation, create a register of findings and put in place a dated action plan. Critical gaps (unencrypted data, exposed secret, non-auditable access) must be corrected in hours or days; major gaps (non-centralized log, untested backup, data deletion procedure to formalize) in weeks; minor gaps (documentation to improve, alert to configure) in a few weeks. Assign responsibility for each correction to a named person with a deadline. Test each correction: a gap marked "corrected" but not tested is not really corrected. Document your compliance evidence: screenshots of AWS configurations, AWS Config audit reports, restore test certificates, records of security approvals. This documentation becomes your proof during an external audit: "On such a date, we validated that encryption was enabled, here is the proof. On such a date, we tested the backup restore, here is the report." Finally, establish a regular review cycle: compliance is not a one-time event after migration, it must be monitored continuously. Schedule a follow-up audit 3 to 6 months after the migration to verify that the configurations remain compliant (configuration drift, undocumented changes) and that no new gap has emerged.
Integrating the post-migration audit with global technical validation The compliance audit does not exist in isolation: it is an integral part of the post-migration validation checklist. While the network team validates connectivity (latency, bandwidth, failover) and the application team validates business functionality and performance, the compliance or security team must validate the compliance and governance requirements in parallel. The three workstreams intersect: a connectivity anomaly can hide a network security problem; an application slowness can reveal a poor isolation of encrypted data. Create a holistic audit plan with clear milestones: D1 to D3 critical audit (sensitive data, access, logging), D3 to D7 major audit (governance, backups, network), D7 to D30 full audit and remediation. Involve the right stakeholders: CIO or CISO for risk appetite, compliance officer or internal auditor for regulatory requirements, security team for technical validation, business leadership for functional compliance requirements. In the end, a single closing meeting validates that all validation criteria (technical and compliance) are satisfied before moving the project to the operational phase.