MongoDB Associate Developer study guide
MongoDB Associate Developer · Work through your exam, one topic at a time.
The MongoDB Associate Developer credential is a certification aimed at application developers who build software against MongoDB rather than at database administrators. It is designed to confirm that a candidate can model documents, write queries and updates, reason about index behaviour, assemble aggregation pipelines, and use the driver and tooling that surround a real application. The MongoDB Associate Developer study guide has 8 sections and about 2,622 words.
01MongoDB Overview and Architecture
A mongod process serves databases, each holding collections of BSON documents. A replica set has exactly one primary that accepts writes, one or more secondaries that continuously apply the primary's oplog, and optionally arbiters that vote in elections but store no data and can never become primary.
331 words, about 2 min02CRUD Operations
insertOne and insertMany return insertedId / insertedIds plus an array of write errors. insertMany is ordered by default: it stops at the first failing document, so later valid documents are never written.
316 words, about 2 min03Indexes and Query Performance
Every collection has an id index. Beyond that: single-field, compound, multikey (created automatically when you index an array field), text, wildcard, hashed, geospatial, TTL (single-field, date-typed, expires on a ~60-second background sweep), unique, sparse, and partial indexes.
326 words, about 2 min04Aggregation Framework
Aggregation is a pipeline of stages, each transforming a stream of documents: match , project , addFields / set , group , sort , limit , skip , unwind , lookup , facet , bucket , count , graphLookup , out , merge . group uses id as the grouping key ( id: null for a grand total) and accumulators sum , avg , min , max , first , last , push , $addToSet .
356 words, about 2 min05Data Modeling
MongoDB schemas are designed around how the application reads and writes, not around normalization. The guiding principle: data that is accessed together should be stored together .
309 words, about 2 min06Transactions
Multi-document transactions give ACID semantics across documents, collections, databases, and (on sharded clusters, since 4.2) shards. They run inside a session: session.startTransaction({readConcern: {level: "snapshot"}, writeConcern: {w: "majority"}}) then commitTransaction() or abortTransaction() .
297 words, about 1 min07Drivers and Application Development
Drivers connect with a URI: mongodb://host:27017/db or mongodb+srv://cluster.example.net/db , which resolves SRV/TXT records for Atlas-style clusters. Build one client per process and reuse it - the client owns a connection pool with maxPoolSize , minPoolSize , and timeouts ( serverSelectionTimeoutMS , socketTimeoutMS , connectTimeoutMS ).
320 words, about 2 min08Atlas and Developer Tooling
Atlas is the managed database service. You create a project, a cluster (shared tiers like M0, or dedicated tiers M10+), database users, and a network access list.
367 words, about 2 min