AWS re:Invent 2025 - Building the future with AWS Serverless (CNS211)

Building the Future with AWS Serverless

Evolving Architectures and Developer Experiences

• Serverless is at an "inflection point" in technology, similar to the impact of the internet in the early 2000s
• Rapid change is a constant, and traditional platform strategies are struggling to keep up with the pace of innovation
• Developers want to move faster and try new ideas, but platform teams are challenged to maintain control and governance
• The goal is to enable "evolutionary architectures" that can rapidly adapt to changing requirements

The Serverless Advantage

• Serverless abstracts away the management of servers, scaling, load balancing, and other infrastructure concerns
• This allows developers to focus on writing business logic and deploying features rapidly
• Serverless provides automatic scaling, reliability, and durability, managed by AWS
• The key benefits are speed, agility, and the ability to focus on innovation rather than infrastructure

Accelerating Development with AI-Powered Tools

• The Serverless MCP (Machine Code Producer) server integrates with AI coding assistants to generate well-architected, compliant serverless code
• This allows developers to quickly create serverless applications with best practices baked in, without manual YAML/infrastructure configuration
• The MCP server provides guidance on appropriate workloads for Lambda, web app development, event-driven architectures, and more

Handling Spiky Traffic with Serverless Scaling

• Lambda can automatically scale to handle sudden traffic spikes, providing a "thousand execution environments every 10 seconds"
• This allows serverless applications to seamlessly handle "needle point" traffic, like flash sales or stadium events, without any manual scaling or provisioning
• Serverless scaling is faster and more flexible than traditional approaches like over-provisioning EC2 capacity

Optimizing Steady-State Workloads with Lambda Managed Instances

• For workloads with more steady-state traffic patterns, Lambda Managed Instances (LMI) provides access to specific EC2 instance types and configurations
• LMI allows tuning compute, memory, and network resources to optimize performance and cost for CPU-intensive or memory-intensive workloads
• LMI integrates with EC2 pricing models like Savings Plans to further optimize costs, while maintaining the serverless developer experience

Building Reliable Workflows with Durable Functions

• Lambda Durable Functions provide a serverless workflow orchestration service, allowing developers to build reliable, long-running processes
• Durable Functions handle retries, checkpointing, and state management automatically, removing the complexity of building distributed, event-driven systems
• Developers can write sequential, idempotent code that is automatically made durable and reliable by the Durable Functions service

Isolating Tenants in Serverless Applications

• Tenant Isolation in Lambda allows creating separate execution environments for each customer or tenant of a SaaS application
• This ensures complete isolation of resources, state, and side effects between tenants, even when using the same Lambda function
• Tenant Isolation enables secure, multi-tenant serverless applications without the overhead of managing separate Lambda functions or infrastructure per tenant

The Serverless Strategy and Roadmap

• Key focus areas for the serverless strategy include:
  • Improving developer experience through better tooling, integrations, and AI-powered code generation
  • Addressing fundamental concerns like cost optimization, observability, and runtime support
  • Expanding the types of workloads that can be effectively run on serverless through innovations like LMI and Durable Functions
• Upcoming roadmap items include native observability/APM support, more runtime options, and continued enhancements to the developer experience