Latest Concurrency Articles

AWS Lambda concurrency is one of the most important concepts to understand before running serverless applications in production. Lambda can scale quickly, but that does not mean every downstream system can handle unlimited parallel requests.

Modern applications rarely do only one thing at a time. They call APIs, query databases, read files, send notifications, process messages, and wait for external services. If every operation runs one after another, the application often spends most of its time waiting instead of doing useful work.

AWS Lambda already gives you horizontal scalability by creating more execution environments when more events arrive. But inside one Lambda invocation, your Python code may still spend a lot of time waiting for APIs, databases, S3, DynamoDB, Redis, or other services.