Interactive reference tools
Calculators and lookups for backend engineers. Every tool is open about its math — use it for a quick answer or read the methodology to learn the formula.
- PostgresLive
Postgres Connection Pool Sizer
Model max_connections, app pools, replicas, and PgBouncer. Shows the failure mode when you cross the thresholds.
- KafkaLive
Kafka Partition & Retention Calculator
Size partitions for throughput and consumer parallelism, with growth headroom. Shows retention storage cost per broker as you adjust inputs.
- RedisLive
Redis Memory Sizer
Estimate Redis memory from key count, value size, and data type — including per-key overhead, fragmentation, fork headroom, and replicas.
- LLMLive
LLM Conversation Cost Calculator
See what turn N — and the whole conversation — actually costs once you account for resending the full history every turn. Verified Claude and GPT-6 pricing, with and without prompt caching.
- GoSoon
Go pprof Flag Reference
Searchable reference of pprof CLI flags and runtime profile types, with usage examples.
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