Mathias Paulenko

Master Testcontainers for integration testing with real databases, message brokers, and APIs. Covers Java, Python, and Node.js with...

Master Vitest for React testing: component tests with Testing Library, hook tests with renderHook, integration tests, mocking, snapshot...

Isolate state in actors that communicate only via messages. Each actor processes one message at a time, eliminating shared-state...

Route unprocessable messages to a separate dead letter queue for inspection and replay. Prevent poison messages from blocking the main...

Build high-throughput queues using atomic operations instead of locks. Multiple threads can enqueue and dequeue concurrently without...

Delay message processing to a scheduled time. Move messages that cannot be processed now to a deferred queue or schedule them for later...

Decouple production and consumption with a shared queue. Producers generate items at their own pace; consumers process them independently...

Broadcast events to multiple independent subscribers. Publishers send messages to a topic without knowing which subscribers exist, enabling...

Process asynchronous data streams with backpressure. Subscribers request N items at a time, preventing fast producers from overwhelming...

Manage database connections across serverless invocations by using external connection poolers, connection reuse, and lightweight clients...

Reuse a fixed set of threads for short-lived tasks instead of creating a new thread per task. Reduces overhead and bounds resource usage...

Document AI agent architecture, tools, memory, reasoning patterns, safety guardrails, evaluation criteria, and deployment configuration....

Checklist for preparing data for LLM and RAG systems: data collection, cleaning, chunking, embedding, deduplication, PII removal, format...

Track token usage and costs per feature, model, and user. Includes cost categories, pricing tables, budget alerts, optimization strategies,...

Operational runbook for LLM production incidents: hallucination events, model outages, cost spikes, safety failures, and degraded quality....

A reusable prompt template library for common LLM tasks: summarization, extraction, classification, code review, translation, and...

Compare LLM models by cost, latency, context window, accuracy, and use case. Includes decision criteria, benchmark results, pricing...

Version your LLM prompts with eval scores, change history, rollback support, and A/B testing. Includes prompt metadata schema, changelog...

A checklist for evaluating RAG system quality: retrieval accuracy, generation faithfulness, context relevance, answer correctness, citation...

Template for documenting cache eviction rules per cache layer: LRU, LFU, TTL, FIFO, random eviction. Includes policy selection matrix,...

Decision template for choosing cache strategies per use case: no-cache, cache-aside, read-through, write-through, write-back, and...

Runbook for warming caches after deployment, restart, or incident: identify hot keys, preload strategies, progressive warmup, health...

Template for defining CDN caching rules and edge behavior: cache keys, TTL by content type, query parameter handling, header forwarding,...

Runbook for safely cancelling long-running async tasks in Python, JavaScript, Go, and Java: cancellation tokens, context propagation,...