name: architecture-paradigm-serverless description: | Serverless FaaS for event-driven workloads with minimal infrastructure management.

Triggers: serverless, FaaS, Lambda, event-driven, pay-per-use Use when: workloads are event-driven with bursty traffic DO NOT use when: long-running processes or stateful operations required. version: 1.0.0 category: architectural-pattern tags: [architecture, serverless, faas, event-driven, cost-optimization] dependencies: [] tools: [cloud-sdk, serverless-framework, IaC-tools] usage_patterns:

• paradigm-implementation
• event-driven-architectures
• cost-optimization complexity: medium estimated_tokens: 700

The Serverless Architecture Paradigm

When to Employ This Paradigm

• When workloads are event-driven and exhibit intermittent or "bursty" traffic patterns.
• When the goal is to minimize infrastructure management and adopt a pay-per-execution cost model.
• When latency constraints from "cold starts" are acceptable for the use case or can be effectively mitigated.

Adoption Steps

1. Identify Functions: Decompose workloads into small, stateless function handlers triggered by events such as HTTP requests, message queues, or scheduled timers.
2. Externalize State: use managed services like databases and queues for all persistent state. Design handlers to be idempotent to validate that repeated executions do not have unintended side effects.
3. Plan Cold-Start Mitigation: For latency-sensitive paths, keep function dependencies minimal. Employ strategies such as provisioned concurrency or "warmer" functions to reduce cold-start times.
4. Implement Instrumentation and Security: Enable detailed tracing and logging for all functions. Adhere to the principle of least privilege with IAM roles and set per-function budgets to control costs.
5. Automate Deployment: Use Infrastructure-as-Code (IaC) frameworks like SAM, CDK, or Terraform to create repeatable and reliable release processes.

Key Deliverables

• An Architecture Decision Record (ADR) that describes function triggers, runtime choices, state management strategies, and cost projections.
• A complete Infrastructure-as-Code (IaC) and CI/CD pipeline for automatically packaging and deploying functions.
• Observability dashboards to monitor key metrics including function duration, error rates, cold-start frequency, and cost.

Risks & Mitigations

• Vendor Lock-in:
  • Mitigation: Where feasible, abstract away provider-specific APIs behind your own interfaces or adopt portable frameworks (e.g., Serverless Framework) to reduce dependency on a single cloud vendor.
• Debugging Challenges:
  • Mitigation: Tracing execution across distributed functions can be complex. Standardize on specific instrumentation libraries and structured logging to simplify debugging.
• Resource Limits:
  • Mitigation: Actively monitor provider-imposed limits, such as concurrency and memory quotas. Design workloads to be shardable or horizontally scalable to stay within these constraints.