L3 Reference Guide
Databases Bigtable vs DynamoDB vs Cassandra vs MongoDB: A NoSQL Decision Framework
A workload-first framework for choosing among four distributed databases without substituting product categories for engineering requirements.
MongoDB
WiredTiger cache, shard hotspots, queryable encryption, query performance.
19 posts
L2 Deep Dive
Databases DynamoDB vs MongoDB: Access-Pattern Keys or Indexed Documents
A principal-engineer comparison of DynamoDB and MongoDB across data modeling, indexing, transactions, sharding, and operational change.
L2 Deep Dive
Databases Bigtable vs MongoDB: Sorted Keyspace or Indexed Documents
A workload-first comparison of Bigtable row-range access and MongoDB document queries, including sharding, indexes, consistency, and analytics isolation.
L1 Field Note
Databases Design an IoT Platform for 10 Million Devices: Bigtable vs DynamoDB vs Cassandra vs MongoDB
A requirements-first design for one million telemetry writes per second, including burst admission, retention math, partitioning, and database tradeoffs.
L1 Field Note
Databases Why Distributed NoSQL Databases Develop Hot Partitions
How skewed keys overload physical partitions across Bigtable, DynamoDB, Cassandra, and MongoDB, with evidence-driven remediation.
L1 Field Note
Databases The Hidden Cost of Secondary Access Patterns in NoSQL
A workload-based method for evaluating DynamoDB GSIs, MongoDB indexes, Cassandra SAI, and Bigtable materialized views without invented amplification constants.
L1 Field Note
Databases The 2 AM NoSQL Incident: Failure Modes Across Bigtable, DynamoDB, Cassandra and MongoDB
A safe, evidence-first incident runbook for throttling, replica loss, elections, hot ranges, retry storms, and recovery across four NoSQL engines.
L2 Deep Dive
Databases From Cassandra to Bigtable, DynamoDB or MongoDB: When Modernization Is Worth It
A correctness-first framework for upgrading Cassandra or migrating to a managed database through ordered change capture, idempotent apply, and evidence-based cutover.
L2 Deep Dive
Databases LLM-Assisted MongoDB Performance Triage: Cache, Replicas and Workload
A self-managed MongoDB incident workflow for correlating WiredTiger cache, host pressure, connections, workload, replication progress, and topology evidence without mistaking symptoms for causes.
L2 Deep Dive
Databases Finding Expensive MongoDB Query Shapes with LLM-Assisted Analysis
A self-managed MongoDB workflow for ranking expensive query shapes, interpreting explain evidence, diagnosing aggregation fan-out, and validating reversible index changes.
L2 Deep Dive
Databases MongoDB Shard Hotspots, Balancing and Replica Performance
A self-managed MongoDB workflow for distinguishing routing fan-out, uneven ownership, range-migration overhead, cleanup debt, and replica-set pressure.
L2 Deep Dive
Databases Securing LLM-Assisted MongoDB Diagnostics: Profiler Data, Audit Logs and Operational Guardrails
A self-managed MongoDB control plane for minimizing diagnostic data, separating access, auditing decisions and actions, and preventing LLM-driven production changes.
L3 Reference Guide
Databases MongoDB Queryable Encryption Architecture Review
A pre-go-live architecture review for MongoDB Queryable Encryption — key management, field classification, query type constraints, driver requirements, and key rotation.
L1 Field Note
Databases G1GC Tuning for Cassandra: What I Actually Look At
How to tune the Java 11 G1 Garbage Collector for Apache Cassandra 4.x, eliminating humongous allocations, evacuation failures, and stop-the-world pauses.
L2 Deep Dive
Databases MongoDB 8.0: Why Queryable Encryption Matters
MongoDB Queryable Encryption stores and queries sensitive fields in encrypted form — what it enables, how it differs from standard FLE, and where the query type constraints bite.
L2 Deep Dive
Databases MongoDB Version Upgrade Risk Review
A systematic runbook for assessing MongoDB version upgrade risk — FCV, driver compatibility, deprecated operators, and rollback paths before any production cutover.
L1 Field Note
Databases MongoDB WiredTiger Cache: Practical Basics
WiredTiger's internal cache is MongoDB's primary memory tier — how to read its metrics, recognize eviction pressure, and size it correctly for your working set.
L2 Deep Dive
Databases MongoDB Query Performance Workflow
A systematic runbook for diagnosing slow MongoDB queries — from explain output through COLLSCAN, index selectivity, in-memory sort, and WiredTiger cache pressure.
L1 Field Note
Databases MongoDB Index Basics: Why Your Query Became Slow
MongoDB's default behavior is a full collection scan when no index supports the query. Here is what you need to know about single-field, compound, and multikey indexes before your collection grows past 10K documents.