Serverless Architecture Design

We design your serverless system around events rather than synchronous HTTP calls. This means your services are decoupled, independently deployable, and naturally resilient to downstream failures.

Core patterns we implement:

• Event Fan-Out — SNS topic publishes to multiple SQS queues, each consumed by a different Lambda function. Order placement triggers inventory check, payment processing, and email notification in parallel.
• Event Sourcing — DynamoDB Streams or Kinesis capture every state change as an immutable event. Downstream consumers rebuild state from the event log.
• Saga Pattern — Step Functions orchestrate multi-step transactions with compensating actions on failure.

// Event schema contract
interface OrderEvent {
  eventId: string;        // UUID v4
  eventType: 'ORDER_PLACED' | 'ORDER_PAID' | 'ORDER_SHIPPED';
  timestamp: string;      // ISO 8601
  version: number;        // Schema version for evolution
  payload: {
    orderId: string;
    customerId: string;
    items: Array<{ sku: string; qty: number; price: number }>;
    total: number;
  };
  metadata: {
    correlationId: string; // Trace across services
    source: string;        // Originating service
  };
}

Every event has a schema version, correlation ID for distributed tracing, and a dead-letter queue for failed processing. We document the event catalog so your team knows exactly what events flow through the system.

We decompose your application into bounded contexts, each owning its data and exposing an event-based interface. A typical SaaS serverless architecture might include:

Services:
  auth/          → Cognito + Lambda authorizers
  orders/        → API GW + Lambda + DynamoDB
  payments/      → Lambda + Stripe webhooks + SQS
  notifications/ → SQS + Lambda + SES/SNS
  analytics/     → Kinesis Firehose + S3 + Athena
  media/         → S3 + Lambda@Edge + CloudFront

Shared Infrastructure:
  event-bus/     → EventBridge custom bus
  vpc/           → Shared VPC for RDS access
  monitoring/    → Centralized CloudWatch + X-Ray

Each service gets its own Terraform module, its own CI/CD pipeline, and its own CloudWatch log group. Cross-service communication happens exclusively through EventBridge or SQS — never direct Lambda-to-Lambda invocation. This ensures each team (or solo developer) can deploy independently without coordination overhead.

Serverless architectures need a data layer that matches their scaling characteristics. We design your data tier with these principles:

• DynamoDB for high-throughput, low-latency CRUD operations with single-table design patterns
• Aurora Serverless v2 when you need relational queries but want automatic scaling
• S3 + Athena for analytical queries over event logs and audit trails
• ElastiCache Serverless for caching and session management

resource "aws_dynamodb_table" "orders" {
  name         = "orders-${var.env}"
  billing_mode = "PAY_PER_REQUEST"
  hash_key     = "PK"
  range_key    = "SK"

  attribute {
    name = "PK"
    type = "S"
  }
  attribute {
    name = "SK"
    type = "S"
  }
  attribute {
    name = "GSI1PK"
    type = "S"
  }
  attribute {
    name = "GSI1SK"
    type = "S"
  }

  global_secondary_index {
    name            = "GSI1"
    hash_key        = "GSI1PK"
    range_key       = "GSI1SK"
    projection_type = "ALL"
  }

  point_in_time_recovery {
    enabled = true
  }

  stream_enabled   = true
  stream_view_type = "NEW_AND_OLD_IMAGES"
}

We implement single-table DynamoDB designs with access pattern documentation, GSI overloading, and TTL-based data expiration for transient records. Point-in-time recovery is always enabled.

You receive a complete architecture package:

• Architecture decision records (ADRs) explaining every design choice
• Terraform modules for each service with environment-based variable files
• Event catalog documenting every event type, schema, and consumer
• Runbook covering deployment, rollback, and incident response
• Cost projection based on your expected traffic patterns

We model your expected costs using the AWS Pricing Calculator with your projected event volumes. A typical SaaS serving 10,000 daily active users with 50 Lambda functions runs under $150/month on a well-designed serverless architecture — compared to $500+/month for equivalent always-on EC2 instances.

The full architecture design is delivered within 7–10 business days. No calls. No meetings. You submit your brief describing your product, expected scale, and current pain points, and we deliver production-ready infrastructure code.