Hey Product Hunt, I kept rebuilding the same back-of-the-envelope calculations at work - "how many Kafka brokers before the NIC saturates?", "will this latency stack blow the SLA?", "is bumping max_connections actually going to help?" - so I turned them into duckkit.dev. What's there now: Kafka - message size & storage, broker sizing, consumer lag / time-to-overflow predictor APIs & rate limiting - rate limit calculator (Nginx/Kong config snippets), versioning helper, breaking-change checker Reliability - latency budget, DORA metrics, incident cost calculator, infrastructure health score (20-question questionnaire → letter grade A–F) Database & infra - PostgreSQL connection pool sizer, K8s pod capacity planner Security - ReDoS vulnerability tester + Roast My Config - paste your postgresql.conf, get a prioritized list of misconfigurations with severity badges A few things that matter to me: - Open a tool, get an answer. No signup, no account, no email. - It's 100% client-side - your inputs never leave the browser. - Disconnect WiFi, it still works. Share a result and the state rides along in the URL. Formulas follow the specs: Kafka KIPs, HikariCP pool formula, 2024 DORA research, IETF rate-limit drafts. If I got something wrong, say so - I'd rather fix it than defend it. Solo project, just shipped. What's the spreadsheet you keep rebuilding?

duckkit.dev

Kafka, rate limits, latency math & more, in your browser

Kafka, rate limits, latency math & more, in your browser