One Year Review of Laravel Vapor: Lessons from Running Serverless PHP in Production

After a full year running a high-traffic Laravel application on Vapor (AWS Lambda), here are the honest lessons learned -- both the wins and the challenges.

What Worked Well

Automatic scaling. Traffic spikes that would have required manual intervention on traditional servers are handled seamlessly. Lambda scales up and down without configuration changes.

Reduced operational burden. No server patching, no OS updates, no capacity planning. The team focuses on application code rather than infrastructure management.

Cost predictability at variable load. Pay-per-request pricing means quiet periods cost almost nothing, while burst capacity is always available without over-provisioning.

Deployment simplicity. Deployments through Vapor are fast and atomic. Rolling back is straightforward if issues emerge.

Challenges Encountered

Cold starts. The most discussed serverless limitation is real but manageable. Prewarming solves most cold start issues at negligible cost. Lambda containers reuse connections after the first request, so only the initial invocation of a new container experiences delay.

Database connections. Each Lambda container opens its own database connection. At scale, this can exhaust database connection limits. Solutions include RDS Proxy for connection pooling or using databases designed for high-concurrency workloads.

Debugging complexity. Distributed serverless functions are harder to debug than a single server. CloudWatch provides logs, but tracing issues across Lambda invocations requires more sophisticated observability tooling.

File system limitations. Lambda provides only a temporary /tmp directory with limited storage. Applications that rely on local file storage need to use S3 or similar services instead.

Execution time limits. Lambda has a 15-minute maximum execution time. Long-running processes like data imports or video processing need to be broken into smaller chunks or moved to different compute services.

Performance Insights

With proper prewarming and database connection management, response times are comparable to traditional server deployments. The overhead of Lambda's execution environment is minimal for well-optimized applications.

The biggest performance gains came from:

1. Implementing prewarming to eliminate cold starts
2. Using connection pooling for the database
3. Leveraging CDN caching aggressively for static assets
4. Moving to Laravel Octane for persistent connections within Lambda containers

Cost Analysis

For applications with variable traffic (quiet nights, busy days, occasional spikes), Vapor typically costs less than provisioning traditional servers for peak capacity. For applications with consistent 24/7 high traffic, the cost comparison becomes closer, and traditional servers may be more economical.

Verdict After One Year

Laravel Vapor is excellent for teams that want to eliminate infrastructure management overhead and have applications with variable traffic patterns. It is not a universal solution -- some workloads are better served by containers or traditional servers. But for the right use case, it significantly reduces operational complexity while providing reliable, scalable infrastructure.