AWS re:Invent 2025 Day 3: The Future of Agent AI
A keynote dedicated to Agent AI and the engineering foundations behind the next chapter of building.
It is Day 3 at re:Invent and today belonged to a single idea. Agents.
Not chatbots. Not prompt wrappers. Real agentic systems with identity, memory, reasoning and policy that you can trust in production.
Swami Sivasubramanian walked onto the stage and delivered a keynote focused entirely on the future of building with AI.

The Future of Agent AI Is Here
Swami opened with something simple. That moment builders know well. Solving a hard problem. That flash of satisfaction when an idea becomes impact. He tied it to examples from The Ocean Cleanup and the Allen Institute where the orchestration behind the scenes matters as much as the end goal.
Then came the question that framed the entire session.
What is an agent and how does it differ from a chatbot?
Strands moves forward
Swami revisited the origin story of the Strands SDK. A moment where the team stepped back and looked at how agents should be implemented so accuracy and quality were not an afterthought. Since its launch in May 2025 it has gone GA, gained hundreds of community contributions and been downloaded more than five million times.
Announcement: Strands Agents Preview for TypeScript and Edge
https://aws.amazon.com/about-aws/whats-new/2025/12/typescript-strands-agents-preview/
Strands now supports Python, TypeScript and edge deployments which means builders can develop and test agents locally before scaling them across environments.
But Swami made it clear. The keynote was not about prototypes. It was about what happens when you try to take agents to production.
The real bottleneck is not the idea
The friction appears when moving from a proof of concept to a real system. Swami broke it down into the pillars that slow teams down.
• Deploying agents at scale
• Capturing memory across interactions
• Identity
• Policy
• Tool use
• Observability
• Debugging
• Consistency
This is where innovation gets stuck. AWS built AgentCore to standardise identity, policy enforcement, evaluation and secure execution.
AgentCore Memory
Swami offered an analogy. The restaurant that remembers your name, your favourite dish or the last thing you ordered. That memory changes the quality of the experience.
Agentic systems need the same capability.
Announcement: AgentCore Episodic Memory
https://www.aboutamazon.com/news/aws/aws-amazon-bedrock-agent-core-ai-agents
Agents can now learn from previous interactions and adapt their behaviour for future tasks.
Customer stories followed. Cox Automotive. Heroku building Vibes. The PGA Tour using multi agent content generation. Caylent replacing thousands of lines of custom logic with an agent driven workflow.
Then a highlight. Blue Origin.
Let innovation be messy. Experiment. Learn fast. Move forward.
Efficiency and evolution
As teams push agents into real environments cost, latency and reliability become important. Swami walked through fine tuning, distillation and reinforcement learning as the foundations of customisation and then shifted into what AWS is doing to simplify the whole process.
Reinforcement fine tuning in Amazon Bedrock
Announcement: Reinforcement Fine Tuning in Amazon Bedrock
https://aws.amazon.com/blogs/aws/improve-model-accuracy-with-reinforcement-fine-tuning-in-amazon-bedrock/
https://aws.amazon.com/about-aws/whats-new/2025/12/bedrock-reinforcement-fine-tuning-66-base-models/
This new capability improves models using reward based feedback. AWS claims an average accuracy improvement of sixty six percent over base models.
Serverless customisation in SageMaker AI
Announcement: Serverless Customisation in SageMaker AI
https://aws.amazon.com/blogs/aws/new-serverless-customization-in-amazon-sagemaker-ai-accelerates-model-fine-tuning/
https://aws.amazon.com/about-aws/whats-new/2025/12/new-serverless-model-customization-capability-amazon-sagemaker-ai/
Select a model, choose a customisation technique and SageMaker handles compute selection and provisioning. Ideal for teams without large engineering or research staff.
Training at scale with HyperPod
Training failures can cost hours or days. Swami introduced two new capabilities on HyperPod that aim to eliminate that waste.
Announcement: Checkpointless and Elastic Training on SageMaker HyperPod
https://aws.amazon.com/blogs/aws/introducing-checkpointless-and-elastic-training-on-amazon-sagemaker-hyperpod/
https://aws.amazon.com/about-aws/whats-new/2025/12/amazon-sagemaker-hyperpod-checkpointless-training/
https://aws.amazon.com/about-aws/whats-new/2025/12/elastic-training-amazon-sagemaker-hyperpod/
Checkpointless training reduces recovery time from hours to minutes by removing the traditional checkpoint cycle.
Elastic training expands into idle capacity and retracts when higher priority workloads need resources.
Customer story: Vercel.
Trust as a requirement
Byron Cook, VP and Distinguished Scientist at Amazon joined the stage to talk about what makes AI trustworthy.
LLMs hallucinate. They can be tricked. They make logical mistakes.
When they run production systems this leads to cost and reputation issues.
Byron walked through how neurosymbolic reasoning is shaping the next generation of guard rails. It was one of the most compelling segments of the morning.
Amazon Nova Act
Announcement: Amazon Nova Act
https://aws.amazon.com/about-aws/whats-new/2025/12/build-automate-production-ui-workflows-nova-act/
Nova Act lets developers automate repetitive browser based workflows using a mix of natural language and deterministic Python steps. It supports escalation to human supervisors and is built on a custom Nova 2 Lite model.
Swami explained imitation learning limitations and how reinforcement learning gyms allow agents to safely explore and learn workflows. Anything in a browser becomes a training environment.
The keynote closed with a return to the builder feeling. That first moment you made something work. The spark that pulls us back every year.
My Keynote Reflection
AI is no longer a novelty or a wave. It is now the fabric of how we modernise organisations. The last two years were experimentation. Now we must productise AI and use AI to accelerate the transformation of our own systems.
AWS continues to focus on removing the undifferentiated heavy lifting. Builders no longer need specialised research backgrounds. They need tools that help them modernise code, tune models, secure datasets and debug at the scale their organisations demand.
Today felt like the blueprint for that path.
Personal Notes
Another big day in the Expo. Wednesday is always the busiest and this year is no exception. I spent a lot of time around the community booth speaking with builders from across regions about their local user group experiences.
The energy was incredible. Learning corners. Lightning talks. Builder labs. And that is just the community pavilion.
Day 3 is still in full flight, and publishing the blog earlier today felt necessary before the schedule filled again. A day that starts with a Swami keynote always feels like a day with direction and momentum.
