AWS Lambda Managed Instances 🚀☁️ #93

re:Flections from re:Invent

Dec 30, 2025

In the previous issue, reInvent brings in some Lambda updates 🚀☁️ #92 looks into some of the updates, including Lambda Durable Functions.

In this issue, we are looking at AWS Lambda Managed Instances, which were rolled out as part of the pre:Invent.

AWS has just bridged the gap between Serverless simplicity and EC2 flexibility. The new AWS Lambda Managed Instances capability allows you to run Lambda functions on dedicated Amazon EC2 capacity—without the headache of managing the underlying infrastructure. As simple as it sounds,

Create a Capacity Provider: Define your VPC, subnets, and preferred EC2 instance types.
Attach Functions: Link your Lambda functions to the Capacity Provider via ARN.
Scale Automatically: AWS monitors traffic and spins up new EC2 capacity in seconds when needed.

This new capability is specifically designed for steady-state workloads, offering up to 72% cost savings through EC2 Reserved Instances and Savings Plans. By introducing a multiconcurrency model, a single execution environment can now handle multiple simultaneous requests, which—combined with pre-provisioned capacity that eliminates cold starts—significantly improves resource efficiency and latency without requiring changes to your core Lambda programming model.

⭐ Pick of the month

This month’s Pick is “Lambda Tips & Tricks“.

Karim Fayed publishes AWS Lambda for Beginners which takes you back to the basics and how to get started with Lambda Functions, also breaking the core concepts, execution cycle, and common pitfalls.

Jones Zachariah Noel N (author) explains different factors that can account for maintaining Lambda function performance during peak traffic and how ALBs and API Gateway play a role in this architecture choice.

🚀 AWSome content to learn from

Benoît Bouré breaks down the common "working with file problems with AppSync” with how to download and upload files to Amazon S3 with AWS AppSync using pre-signed URLs.

Anna Pastushko’s AppSync for GraphQL: When it actually shines gives a complete breakdown of AppSync and how it shines for real-time subscriptions, data federation to reality check with production hurdles.

Jeremy Daly’s We’re Already Living in a Post-Serverless World reflects on how infrastructure has been Serverless, but now it’s more about autonomous, powered with AI deciding the “right infrastructure”.

Corey Quinn reflects on AWS Database Savings Plans: Six Years of Complaining Finally Pays Off, with AWS being receptive to customers’ requests on Savings Plan for Databases.

Andres Moreno dives into Step Functions without ASL? Welcome Lambda Durable Functions with a walkthrough of the SAM to function code with detailed troubleshooting.

Maik Wiesmüller digs into the new announcement of AWS Lambda on EC2 and shares the experience of building with the capacity providers and setting up auto scaling with provisioning your Lambda function.

Nirav Shah shares how Lambda Managed Instances with EC2 flexibility address the problem with traditional Lambda functions, with a breakdown of the problem and how Lambda Managed Instances addresses it.

Minoltan Issack retrospects how Serverless is changing and what are the 10 features from re:Invent you should not miss out from pricing to infrastructure changes, with pro-networking!

Jones Zachariah Noel N (author) reflects on some of the takeaways and announcements from AWS re:Invent 2025: AI Agents take over while core compute gets reinvented.

⚒️ What's happening with Serverless tools, samples, and projects

Andres Moreno has published a sample with a durable function.

Awedis Keofteian has published Lambda durable function callback. (Also read more about it in the blog post).

Emmett is a NodeJS library for EDA.

🎙️ Podcasts, videos and live-streams

On AntStack TV, Chinmayee Holla explains AWS Lambda Durable Functions.

On Believe in Serverless, Danielle Heberling takes on AWS Anti-Patterns that will cost you later.

Thomas Taylor published a guide on Serverless LangChain Agents on AWS Lambda.

Some of the reInvent sessions -

Simplifying orchestrations with JSONata and AWS Step Functions by Ishita Chakraborty.
Designing resilient Serverless Applications by Stephen Liedig.
A decade of API Gateway: Architecting the future of API Management by Giedrius Praspaliauskas and Srijan Bhattacharya.

🗓️ Mark your calendars

AWS re:Incent re:Cap by AWS UG Cloud Del Norte virtually on Jan 15th, 2025.

AWS Community Days are happening -

ACD Kochi on December 20th, 2025.
ACD Israel on January 15th, 2026.
ACD Rajasthan on February 28th, 2026. CFP is currently open until January 12th, 2026.
ACD Pune on March 21st, 2026.
ACD Romania on April 23rd-24th, 2026. CFP is currently open until February 15th, 2026.