For more than a decade, software teams have been balancing the trade-offs between monoliths and microservices on AWS. From simple Lambdaliths to complex design patterns to achieve microservices benefits, this debate has been anything but settled.

At AWS re:Invent, AWS introduced Lambda Durable Functions with an interesting premise: build like a monolith, deploy as microservices. By bringing durable execution to Lambda Functions, AWS is challenging assumptions about how serverless applications should be designed.

In this talk, I will walk through a real-world refactor of a multi-step data pipeline at PostNL, migrating from AWS Step Functions to AWS Lambda Durable Functions and still respecting the application's design pattern. We’ll explore what worked, what didn’t, and the trade-offs we encountered along the way.

When you walk out of this session, you will understand how Lambda Durable Functions work under the hood, when they are a better fit than state machines, the trade-offs they introduce, and how they influence microservice design decisions in practice, or whether this marks the end of the monolith vs. microservices debate as we know it.

This session is targeted at Developers, Software Engineers, Tech Leads, or teams familiar with AWS and Lambda Functions, interested in achieving solid orchestration patterns.

This talk falls into the 300-400 level, and I expect you to be familiar with AWS, Lambda, as well basic understanding of Step Functions.

The duration is 25 minutes of focused content, or 30 minutes with Q&A.