dkduckkit.dev

——— free developer tools

Calculators for platform engineers

Interactive tools for Kafka sizing, API design, and rate limiting. No signup. No paywalls.

6 tools live0 signups<1s to result
—— All tools

Kafka Message Size Calculator

Calculate Kafka message size, storage, bandwidth and optimal configuration. Compression, batching and replication.

kafka message size calculatorOpen

Kafka Consumer Lag Predictor

Predict when your consumer group will overflow. Size consumers and simulate failures before production incidents.

kafka consumer lag calculatorOpen

API Rate Limit Calculator

Optimal rate limits from traffic and consumers. Nginx, Kong, AWS snippets and IETF headers.

api rate limit calculatorOpen

API Versioning Decision Helper

Interactive SemVer: decide major, minor, or patch bumps with clear rationale for API changes.

api versioningOpen

System Latency Budget Calculator

Build your architecture from reference hop latencies and see instantly if you fit your SLA — interactive latency numbers for engineers.

latency budget calculatorOpen

ReDoS Vulnerability Tester

Analyze JavaScript-style regex for catastrophic backtracking: scores from redos-detector, static heuristics, evil inputs, and bounded timing.

redos vulnerability testerOpen

API Breaking Change Checker

Compare two JSON Schema or OpenAPI specs and see breaking vs safe changes.

api breaking change checkercoming soon