Notes from
the build.

What I learn while designing and running cloud and backend systems: migrations, trade-offs and the parts that were harder than the diagram suggested.

Incoming email flow: SES stores the original .eml in S3, Lambda processes it, and a web app reads the results

LatestSep 2026 · 2 min read

Store the original first: an email pipeline on SES, S3 and Lambda

Processing incoming email straight in Lambda was simpler, but it tied the raw message to the processing step. Saving every .eml to S3 first makes processing disposable: change the code, fix a bug or rebuild derived data, then replay the originals.

AWSServerlessArchitecture

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More notes

Sep 2026CI/CD without AWS keys: GitHub Actions, OIDC and STS

AWSCI/CDOIDC

Sep 2026Moving Belza into its own VPC, without breaking what was running

AWSNetworkingVPC

Notes fromthe build.

Store the original first: an email pipeline on SES, S3 and Lambda

Notes from
the build.