dba-mongodb

dba-mongodb is the MongoDB heuristics catalogue that gives the dba role a document-database expert’s eye on a change. Mongo’s flexibility is also its trap: a schema that’s easy to write is easy to model wrong, and the cost shows up much later. Every finding ships with a Mongo shell command to fix it.

What it solves

Document modeling decisions are the ones that quietly determine whether a Mongo deployment scales or stalls — and they’re invisible to a generalist reviewer. Embed versus reference, the wrong index order for the query, a shard key that hot-spots every write onto one node, a collection with no TTL that grows forever. None of these break in the demo; all of them bite in production. This skill makes the document-database judgment part of the review.

How it works

It runs a catalogue of Mongo-specific heuristics:

• indexing — compound-index order by the ESR rule (Equality, Sort, Range);
• modeling — embed vs. reference for the actual access pattern;
• query — collection scans, unbounded $lookup, unindexed sorts;
• migration — schema changes safe to run online;
• retention (TTL), capacity (shard key), security, concurrency — growth, even distribution, exposure, and write-conflict hazards.

Each finding carries a severity and a concrete Mongo shell command, so the fix is one paste away.

When to use

On any change to a MongoDB data layer — a new collection, an aggregation, an index or shard-key decision. It is the dba role’s MongoDB catalogue, alongside dba-mssql, dba-postgres, and dba-redis.