TurnKeeper's answer:

TypeScript (Bolt.js for Slack), PostgreSQL with an append-only event ledger as the source of truth, Docker, hosted on EU infrastructure (Hetzner, Germany) behind Cloudflare. Payments via Paddle as merchant of record.

TurnKeeper's answer:

Every assignment is explainable. TurnKeeper keeps an append-only ledger of all assignments, skips, swaps and absences, so it can always answer "why is it my turn?" — skipped turns transfer fairness credit instead of silently piling up on whoever is next. And there is deliberately no AI in the decision path: a tool that decides whose turn it is should be deterministic and auditable, not probabilistic.

TurnKeeper's answer:

Software and support teams of roughly 4–50 people who rotate recurring duties through Slack: support triage, standup facilitation, code review duty, on-call handoffs. Typically teams that have outgrown the pinned spreadsheet or /remind hack but don't want a full incident-management platform for duties that aren't incidents.

TurnKeeper's answer:

Three reasons: transparent fairness (an audit trail instead of a black box), honest vacation handling (absences are skipped visibly, with the reason shown in the announcement), and flat pricing — €19/month per Slack workspace with unlimited users, versus the per-user pricing most alternatives charge, which punishes growing teams. It's also EU-hosted (Germany) with minimal Slack permissions: it cannot read your messages.

TurnKeeper's answer:

Built by a solo founder after seeing the same pattern at every company: rotations managed via outdated spreadsheets, reminders that ping people on vacation, and homegrown bots that die when their author changes teams. Slack's Workflow Builder still can't do rotations (no persistent state, no "next person" step), so TurnKeeper fills that gap with boring, reliable, auditable software.