What is the difference between AWS Lambda and Google Cloud Functions?

Both are FaaS platforms but differ in several ways: (1) Maturity/ecosystem — Lambda is older (2014 vs. 2016), has more triggers (~200 AWS services), and a larger community; (2) Runtime support — Lambda supports more runtimes including Java, Ruby, and custom runtimes; GCF supports Node.js, Python, Go, Java, .NET, Ruby, PHP; (3) Timeout — Lambda: 15 minutes; GCF: 60 minutes (1st gen: 9 min); (4) Concurrency — Lambda: 1000 concurrent by default; GCF: 3000 concurrent; (5) Minimum billing — Lambda: 1ms increments; GCF: 100ms minimum; (6) Container images — Lambda supports container images up to 10GB; GCF has Cloud Run for container-based serverless; (7) VPC integration — Lambda has mature VPC integration; GCF added VPC support later; (8) Tooling — Lambda has SAM, CDK, and the Serverless Framework; GCF uses gcloud CLI and Terraform. The choice often depends on your existing cloud provider commitment.