Hands-on AWS tutorials that run entirely on your laptop. No AWS account, no credit card, no credentials, no bill.

Each tutorial uses Floci - an MIT-licensed local cloud emulator that speaks the real AWS wire protocol on localhost:4566. You write ordinary aws CLI commands and ordinary boto3 / AWS SDK v3 code. The only difference from real AWS is a single endpoint override, and every tutorial points at exactly where that line is.

Start here

irm https://floci.io/install.ps1 | iex

floci start && eval $(floci env)

aws s3 mb s3://hello-floci && aws s3 ls

If that listed your bucket, you are ready.

Tutorials

# Topic Services Checks Time
00 Setup - 11 20 min
01 Object storage S3 17 50 min
02 Key-value data DynamoDB 16 60 min
03 Serverless functions Lambda 15 60 min
04 Queues and pub/sub SQS, SNS 21 60 min
05 A full REST API API Gateway + Lambda + DynamoDB 23 75 min
06 Identity and secrets IAM, STS, Secrets Manager 23 70 min
07 Orchestration Step Functions, EventBridge 24 70 min
08 Infrastructure as code CloudFormation 26 60 min

Every tutorial has command line steps, the same thing in both boto3 and the Node SDK, three exercises, and an honest account of where the emulator and real AWS part company. 176 checks passing across all nine.

Why local emulation

Learning AWS the normal way means an account, a card on file, and a standing risk of forgetting to tear something down. That friction is the single biggest barrier to actually practising cloud work rather than reading about it.

Floci removes it. It starts in roughly 24ms, idles at about 13 MiB, accepts any credentials, and covers 68 AWS services. Lambda, RDS, EC2, ECS and OpenSearch are not emulated at all - Floci launches real engines in Docker - so those behave very close to production.

The trade is fidelity. Emulation is not the real thing, and pretending otherwise would make these tutorials actively harmful. So every tutorial ends with a “How this differs from real AWS” section, populated from a coverage matrix that records what was tested by hand rather than what the vendor documentation claims.

What the testing actually found

Writing those verification scripts turned up real differences that are not documented anywhere. Each one is now written into the relevant tutorial and asserted in its test, so a future Floci release that changes the behaviour will break the build rather than quietly make the tutorial wrong.

Service What differs Why it matters
S3 Overwriting an object that predates versioning destroys its null version. Real AWS keeps it. Silent data loss, with no error raised.
DynamoDB Secondary indexes update instantly. Real AWS indexes are eventually consistent. Write-then-immediately-query works here and fails intermittently in production.
SQS Standard queues never reordered or duplicated a message. Real AWS permits both. A consumer that is not idempotent passes here and fails in production.
Lambda The IAM execution role is not validated at all. On real AWS a role missing log permissions gives you a function that runs but writes nothing.
IAM Policies are stored and correctly simulated, but never enforced. An explicit Deny is ignored, and invented credentials work. The largest gap in the series. A security control that looks present and does nothing.
KMS encrypt does not encrypt. The plaintext is recoverable from the ciphertext with no key. Anything you put through KMS locally is readable by anyone holding the output.

How the tutorials are built

Every tutorial ships a verify.sh that runs its own documented commands headless and exits non-zero if any of them stop working. Continuous integration runs all of them on every push and once a week, so a new Floci release cannot quietly break a tutorial without anyone noticing.

Source: github.com/Sreekant13/floci-aws-tutorials

Licensed MIT. Use them, fork them, teach from them.

Before you go

You are about to spend a few hours breaking a cloud that cannot bill you. That is a genuinely rare position to be in, so please misuse it. Delete the thing you were told not to delete. Feed the function garbage. Run a verify.sh and try to make it fail. The worst outcome is that you type floci stop and everything you did evaporates for free.

Nothing here has a credit card attached, so there is no such thing as an expensive mistake. Go and make some cheap ones.

If any of this was useful, a star takes one click and helps the next student find it. If you know somebody who has been putting off learning AWS because of the credit card form, send them this way.

Good luck, and enjoy the low floor.

Say hello

Built by Sreekant Baheti.

Found a typo, a broken command, or a place where Floci does something none of these pages warn you about? Open an issue. Turning up a new divergence is the single most valuable thing you can contribute here, and I will credit you for it on the page you break.

Built as a research assistant project under Dr. Saty Raghavachary, Computer Science Department, University of Southern California.