Blog
Writing on billing, provisioning and hosting.
- Software4 min read
Why a hosting control panel should never log in to your servers
A panel that reaches into servers to change them is a single key to every machine, and it only knows what it did, not what is there. Turn the arrow round.
Kostalbreeze · 10 October 2026 - Software5 min read
An overdue invoice should follow a timetable both sides can read in advance
What happens to an unpaid invoice day by day, from the first reminder to termination, and what a customer and a hosting company can each do at every step.
Kostalbreeze · 10 October 2026 - Software5 min read
We sell billing, the control panel and monitoring separately because each one owns different facts
Zephyr, kstack and Standby are three products, not a suite. The reason is a rule about who owns which fact, and it is just as useful if you only ever run one of them.
Kostalbreeze · 10 October 2026 - Software4 min read
A checkout should refuse the order it cannot fulfil
Billing systems take the money first and provision second. That ordering is correct, and it means every gap in your provisioning becomes a charge you have to explain and a refund you have to make.
Kostalbreeze · 20 September 2026 - Software3 min read
A rate limit and a spend cap should not return the same status code
429 means try again shortly. 403 means stop. Return 429 when someone has hit a monthly budget and every well-behaved client you serve will retry, politely and forever, against a wall.
Kostalbreeze · 20 September 2026 - Software3 min read
Migrating off WHMCS without a bad weekend
The reason people stay on billing software they dislike is the migration. It is survivable if you rehearse it instead of attempting it.
Kostalbreeze · 20 September 2026
