Tools
Interactive resources and downloads built by Jorel del Portal: calculators and checklists for designing and operating critical systems. Using them takes no signup; the premium downloads (PDF and Markdown) come with your email. Looking for the third-party software I use in production? That lives in the Toolbox.
Available now
CalculatorNew
Availability calculator
Turn your SLA target into real downtime —per year, month and week— and check your architecture against the 8-domain checklist. The printable version is free; the PDF and Markdown, with your email.
- SLA → allowed downtime (year / month / week)
- How much of your unavailability budget is left
- 8-domain checklist: PDF, Markdown, or printable
Also available
Retry budget
Amplification, worst-case end-to-end and whether your policy fits the caller's timeout.
CalculatorSLO burn-rate
Remaining error budget, burn speed and alert thresholds.
CalculatorLatency and percentiles
Probability of hitting the tail with fan-out and the real cost of chaining calls.
Next
Capacity and saturation
Utilization, queues and headroom for the worst case: losing a zone during a peak.
One tool ships at a time, once it passes real tests — no calendar. Want to know when the next one lands? Follow the newsletter.