Field notes for solving real production problems — read through an AI-assisted engineering lens.

Practical write-ups across PostgreSQL, MySQL, MongoDB, Cassandra, Valkey, Elasticsearch, OpenSearch, and vector search — plus the cloud platforms and AI agent patterns that operate them.

Browse by Technology

Nine engines and operating layers, each at a different point on its own learning curve — some run for twenty years, some picked up recently over the last couple of years. AI engineering is the lens applied across all of them, not a separate silo. The posts under each one show the depth better than any label could.

AI The lens across every card below · 159 posts

AI Engineering — agents, evals, MCP, and operating guardrails

Agents, evals, MCP, and the guardrails that connect back to every system below.

Pg 82 posts

PostgreSQL

MVCC, autovacuum, replication, Aurora and Citus scaling, pgvector.

  • PostgreSQL on Kubernetes: HA Requires Fencing, Replication, and Recovery
  • MySQL HeatWave Architecture: Why Oracle Built an Analytics Engine Around MySQL
My 31 posts

MySQL

InnoDB internals, replication lag, Aurora MySQL, sharded write scaling.

  • MySQL HeatWave in Production: Operations, Autopilot, Lakehouse, and Failure Modes
  • Vitess for MySQL Sharding: Routing, Resharding, and Failure Boundaries
Mo 19 posts

MongoDB

WiredTiger cache, shard hotspots, queryable encryption, query performance.

  • Bigtable vs DynamoDB vs Cassandra vs MongoDB: A NoSQL Decision Framework
  • DynamoDB vs MongoDB: Access-Pattern Keys or Indexed Documents
Ca 38 posts

Cassandra

Write path fundamentals, compaction strategy, tombstone observability.

  • Bigtable vs DynamoDB vs Cassandra vs MongoDB: A NoSQL Decision Framework
  • Bigtable vs Cassandra: Similar Data Models, Different Operating Boundaries
☁ 45 posts

AWS & On-Prem

AWS and on-prem infrastructure — Terraform, Kubernetes, migration cost.

  • MySQL RDS 8.4 vs Amazon Aurora: The Write Scaling and Storage Tradeoff
  • When OpenSearch Vector Search Fails: Shard Sizing, Recall Loss, and Hot Nodes
Vk 9 posts

Valkey / Redis

Eviction policy, licensing history, ElastiCache performance triage.

  • LLM-Assisted Valkey Performance Triage on EC2: Memory, CPU, Latency and Evictions
  • Finding Expensive Valkey Commands and Data Structures
ES 14 posts

Elasticsearch / OpenSearch

Shard and heap troubleshooting, hybrid search, kNN architecture.

  • When Search Becomes a Product: OpenSearch and Elasticsearch Architecture
  • OpenSearch Hybrid Search for Product Catalogs: BM25, Vectors, Filters, and Rerankers
Vc 30 posts

Vector Search

Deep pgvector internals, plus newer ground with Qdrant and Weaviate as the vector landscape expands.

  • pgvector Backup and Restore: Why Embeddings Change Your RPO/RTO Thinking
  • pgvector on Aurora PostgreSQL: What DBAs Need to Watch

Start Here

New to the site? These posts are ordered as a reading path, while Latest Notes below is ordered by publication date.

  1. AI Token Cost Overruns: Why AI Coding Assistants Are Becoming the New Cloud Bill Problem AI Engineering · L2 Deep Dive
  2. Harness Engineering: The 2026 Breakthrough Concept AI Engineering · L1 Field Note
  3. Agent Productivity Depends on Context Throughput AI Engineering · L2 Deep Dive
  4. From Metrics to Root Cause: Why Database Troubleshooting Needs Evidence Correlation AI Engineering · L1 Field Note
  5. Cloud Architecture Review Checklist for Database-Backed Applications Databases · L3 Reference Guide
  6. Why Reads Scale More Easily Than Writes: The Single-Writer Ceiling Databases · L3 Reference Guide

Latest Notes

Recent field notes and breakdowns across AI engineering, databases, cloud, and system design.

Topics

Browse by the production problems the notes are written around.

80 posts

AI Engineering

Agents, context engineering, harness design, MCP, evaluation, token efficiency, and AI-assisted engineering workflows.

  • Retrieve, Constrain, Verify, Abstain: A Near-Zero Hallucination RAG Architecture, Reviewed
  • Agentic RAG: When Natural Language Search Becomes an Action System
  • The Agentic Orchestration Layer: Scaling Database Operations from Sailor to Captain
221 posts

Databases

PostgreSQL, Aurora, MySQL, Oracle, Cassandra, MongoDB, pgvector, replication, migrations, indexing, and database operations.

  • MySQL HeatWave in Production: Operations, Autopilot, Lakehouse, and Failure Modes
  • PostgreSQL on Kubernetes: HA Requires Fencing, Replication, and Recovery
  • Vitess for MySQL Sharding: Routing, Resharding, and Failure Boundaries
86 posts

Cloud & Platform

AWS, Azure, GCP, OCI, Terraform, Kubernetes, CI/CD, Cloudflare, developer platforms, and operational control planes.

  • The Math Behind Database Reserved Instances: When to Wait
  • BigQuery Cost Optimization: On-Demand vs Slot Commitments
  • Database Licensing Cost Across AWS, Azure, GCP, and OCI
50 posts

System Design

Architecture reviews, scalability, failure modes, guardrails, distributed systems, reliability boundaries, and production tradeoffs.

  • Why Your Non-Prod Databases Cost as Much as Production
  • 330 Redundant Data Centers All Failed Simultaneously — Because They Were Identical
  • The End of Single-Signal Alerting: Correlating Metrics, Logs, Traces, Deployments, and Cost
26 posts

Engineering Fundamentals

Core engineering principles, debugging workflows, observability, performance basics, reviews, and practical operating habits.

  • Scaling PostgreSQL Reads with AlloyDB: Read Pools, Columnar Execution, and TQF
  • Cloud SQL PostgreSQL Performance at Scale: Data Cache, Replicas, and Evidence-Driven Tuning
  • AI Cost Observability Dashboard: LangSmith vs Helicone
121 posts

Field Notes

Short practical observations, checklists, production lessons, debugging notes, and decision patterns from real engineering work.

  • Design an IoT Platform for 10 Million Devices: Bigtable vs DynamoDB vs Cassandra vs MongoDB
  • Why Distributed NoSQL Databases Develop Hot Partitions
  • The Hidden Cost of Secondary Access Patterns in NoSQL

Series

Multi-post arcs that connect practical decisions across a topic.