Skylight

What Skylight is

Skylight is a cloud-based profiler for Ruby and Rails applications. It helps teams locate performance problems by ranking endpoints with an “agony” measure that combines popularity and response time. A deployment graph places releases alongside performance data, so teams can follow how code changes affect an application. Skylight supports Rails, Sinatra, and Grape, and analyzes background jobs running through Sidekiq, DelayedJob, and ActiveJob.

Its diagnostics can flag allocation hogs and repeated queries. Endpoint timelines show aggregated, sanitized SQL queries, while the dashboard and endpoint event sequences group GraphQL queries by name. A weekly performance report identifies endpoints that improved, warns about slowdowns, and highlights endpoints that have declined over six weeks. Each account includes 100,000 traces per month at no charge. Paid tiers start at $20 a month, with billing based on monthly trace volume across apps and tiers adjusting to that volume. Skylight also offers a 30-day trial without a credit card. Open-source apps may apply for free public performance reporting, with setup instructions sent after approval. The service is available for API, Linux, macOS, and web, and documentation covers setup, instrumentation, performance tips, background jobs, and troubleshooting.

Who it suits

Skylight suits teams responsible for Ruby applications that need to find slow endpoints, inspect queries, and track performance around deployments. It also fits teams using supported background job systems or GraphQL, and open-source app maintainers may apply for public performance reporting.

Limits

The free allowance covers 100,000 traces per month for every account. Paid tiers start at $20 a month and adjust to monthly trace volume across all apps; open-source public reporting is available only after application approval.

Getting started

1. Visit skylight.io and sign up for the free account or 30-day trial.
2. Choose the API, Linux, macOS, or web environment relevant to your application.
3. Follow the documentation for setup and instrumentation.
4. Configure performance analysis for supported frameworks and background job queues.
5. For free public reporting of an open-source app, apply and wait for approval and setup instructions.

Verdict

Pick Skylight if you run a Ruby or Rails application and want endpoint, query, deployment, and background job performance analysis. The monthly free trace allowance and 30-day trial offer ways to begin. Teams that need real user monitoring should look elsewhere, as Skylight does not provide it.