April 4, 2026 · Tim Fraser, Cloud Operations Lead
Building a Continuous Audit Trail for Your Cloud Infrastructure
When your auditor asks "how do you know your cloud environment was secure last March?", the wrong answer is "we think it was." The right answer is a dated report from March that shows exactly what was checked and what was found.
Most FinTech companies assemble audit evidence in a scramble before the audit itself — generating reports, taking screenshots, writing narratives. Auditors can tell the difference between evidence captured as part of ongoing operations and evidence manufactured the week before.
The better approach: an audit trail that generates itself as a byproduct of how you actually manage your infrastructure.
What auditors want to see
Auditors evaluating your cloud infrastructure typically want evidence in three categories:
Configuration evidence: What does your environment look like now, and what did it look like at specific points in the past? Auditors want to see that controls were in place consistently, not just on the day they visited. Change evidence: What changed, when, and who made the change? Both the original modification and any reversal should be visible. Assessment evidence: Did someone review the environment and verify that controls were working? CloudTrail proves logging exists, but it doesn't prove anyone looked at those logs. Auditors want documented findings from regular reviews.The AWS services that provide raw evidence
CloudTrail records every API call made in your account — who called what, when, from which IP address. Enable it in all regions, write logs to a separate account's S3 bucket, and enable log file integrity validation so you can prove the logs haven't been tampered with. AWS Config records the configuration of your resources over time, letting you answer questions like "what did this security group look like three months ago?" Config Rules evaluate your resources against specific policies and record compliance status over time. Credential reports show IAM usage patterns — which users have MFA enabled, when access keys were last used, and which accounts are inactive. Download and archive these monthly.The gap that raw logs don't fill
CloudTrail and AWS Config give you raw data, not assessments. Auditors want someone to have reviewed that data, identified issues, and documented findings on a regular cadence. Most organisations have logging in place but lack the regular, documented assessments that interpret the data and flag issues.
Building the cadence
A practical continuous audit trail for a FinTech AWS environment looks like this:
Daily (automated): AWS Config Rules evaluate compliance. GuardDuty analyses logs for threats. CloudWatch alarms trigger on high-severity events. These run without human intervention and produce timestamped records. Weekly (reviewed by someone): A structured review covering resource inventory, security configuration, access patterns, and cost trends. The review produces a dated document recording what was checked, what was found, and any actions needed. This is the evidence that proves ongoing oversight. Monthly: Review IAM access, archive credential reports, verify logging configurations, and check that previous findings have been addressed. Quarterly: Penetration testing results, incident response plan updates, and access reviews feeding into regulatory reporting.The weekly review is the most important element. It's frequent enough to catch drift before it becomes a compliance gap, and it produces regular evidence of continuous monitoring.
Using plainfra as your weekly assessment tool
plainfra connects to your AWS account with read-only access and reviews your infrastructure against security and operational best practices. Each report covers resource inventory, security groups, IAM policies, encryption status, public exposure, and cost trends.
Each report is dated and stored. Over a year, you accumulate 52 timestamped reports documenting your security posture at each point in time. When audit time comes, you hand the auditor a folder of weekly reports showing ongoing oversight — a fundamentally different conversation than scrambling to generate evidence during audit prep.
> "Generate a security and compliance assessment of our AWS environment, covering IAM, encryption, network security, and logging configuration."
plainfra checks your actual configurations, flags anything that doesn't meet best practice, and gives you a report you can archive as audit evidence. One question, every week, builds a year of compliance documentation.
Try plainfra free → 50K tokens, 7 days, no charge. Or see the interactive demo →.