I gave a talk at the ninth in-person meetup of the AWS User Group Damascus on 26 September 2026. Here is the short version, with code you can try yourself.
📑 Slides: An Introduction to Serverless Computing on AWS
What is serverless?
Serverless is where a 20-year trend ends up: physical servers, then virtual machines, then containers, and now just your code. Put simply, you don’t provision, patch or scale servers, and you pay only when your code runs.
A serverless service has four traits: no server management, automatic scaling (down to zero too), pay-per-use billing, and event-driven execution. The fourth is the one that changes how you design: stop thinking in processes that wait, and start thinking in functions that react.
Serverless also doesn’t just mean Lambda. API Gateway, DynamoDB, S3, SQS and EventBridge are all serverless too.
When should you use it?
Serverless wins when your traffic graph looks like mountains: APIs with variable traffic, event processing, scheduled jobs, glue code between services, and MVPs. Think twice for jobs longer than 15 minutes, latency-critical paths where cold starts hurt, high steady load, stateful work, or GPUs.
Rule of thumb: if traffic is spiky, go serverless. If it’s a flat plateau, compare the cost against containers, and choose whichever is cheaper to operate, not just cheaper on the bill.
The demos
- A REST endpoint (API Gateway → Lambda → DynamoDB) in about 20 lines. There’s no Express app and no
listen(). One tip: create SDK clients outside the handler so warm invocations can reuse them. - Reacting to an upload (S3 → Lambda → DynamoDB). You drop a JSON file in a bucket, and the records show up in DynamoDB seconds later, with no polling and no cron.
Code for both is in aws-serverless-sample-webapp. You can deploy it with SAM, or try the live app.
- A Telegram bot: Telegram sends each message to a webhook, and API Gateway invokes a Lambda that replies with a serverless fact. A secret-token header blocks any caller that isn’t Telegram, and the bot costs nothing between chats. The code is in aws-serverless-telegram-bot-typescript, or you can say hi to the bot.
Key takeaways
- Think in events, not servers.
- Use it where traffic is spiky.
- Respect the trade-offs: cold starts, the 15-minute limit, and cost at steady load.
- Learn five services first: Lambda, API Gateway, DynamoDB, S3 and SQS.
Start small by moving one cron job or one API endpoint. With sam init and then sam deploy --guided, you can go from an empty account to a live endpoint in about twenty minutes.