Data models beyond tables
NoSQL Interview Questions
Documents, key-value stores, wide columns, graphs and the consistency trade-offs behind production NoSQL systems.
40 questions10 easy22 medium8 hard0/40 learned
01What is NoSQL and when is it a good fit?Easynosql · data modeling · scalability02What are the main types of NoSQL databases?Easynosql · document stores · key-value03How do you choose between NoSQL and a relational database?Easysql · nosql · trade-offs04What does the CAP theorem actually say?Mediumcap theorem · consistency · partition tolerance05How does eventual consistency work and how do you handle it?Mediumeventual consistency · replication · session guarantees06How do document databases store and query data?Easydocument databases · mongodb · aggregates07What are key-value stores and what are their limits?Easykey-value · redis · dynamodb08How do wide-column stores organise data?Mediumwide-column · cassandra · partitioning09When should you use a graph database?Mediumgraph databases · neo4j · traversal10How do you approach data modeling in NoSQL?Mediumdata modeling · access patterns · aggregates11Why is denormalization common in NoSQL?Mediumdenormalization · duplication · read performance12When do you embed data and when do you reference it?Mediumembedding · referencing · document modeling13How do access patterns shape a NoSQL schema?Mediumaccess patterns · key design · indexes14What is sharding and how do you choose a shard key?Mediumsharding · shard key · scalability15How does replication work and what does it protect against?Mediumreplication · failover · quorum16What partitioning strategies do NoSQL databases use?Mediumpartitioning · range partitioning · hash partitioning17How do consistency levels work in distributed databases?Hardconsistency levels · quorums · cassandra18How do transactions work in NoSQL databases?Hardtransactions · atomicity · mongodb19How does MongoDB represent and query documents?Easymongodb · bson · documents20How do you design indexes in MongoDB?Mediummongodb · indexes · query performance21How does the MongoDB aggregation pipeline work?Mediummongodb · aggregation · pipeline22Which Redis data structures would you use and when?Easyredis · data structures · caching23How does Redis persistence work?Mediumredis · persistence · durability24How does Redis eviction work?Easyredis · eviction · caching25How does Cassandra's architecture work?Hardcassandra · sstables · gossip26How do consistency levels and replication interact in Cassandra?Hardcassandra · consistency · quorum27How do you choose a DynamoDB partition key?Mediumdynamodb · partition key · key design28How do DynamoDB read and write capacity units work?Mediumdynamodb · capacity · throughput29How do you model data in Neo4j?Mediumneo4j · graph modeling · cypher30How do you diagnose and improve NoSQL query performance?Mediumquery performance · indexes · explain plans31What causes a hot partition and how do you fix it?Hardhot partitions · skew · partition key32How do secondary indexes work in NoSQL systems?Mediumsecondary indexes · gsi · query patterns33How do you evolve a schema in a NoSQL database?Hardschema migration · backfill · versioning34How do you plan backups and restores for a NoSQL database?Mediumbackup · restore · disaster recovery35What should you monitor in a NoSQL deployment?Mediummonitoring · observability · metrics36How do you secure a NoSQL database?Mediumsecurity · authentication · encryption37How do you control NoSQL costs in production?Hardcost optimization · capacity · ttl38How do you choose a database for a new system?Harddatabase selection · trade-offs · architecture39What are common NoSQL mistakes?Easyanti-patterns · modeling · operations40What are NoSQL best practices in production?Easybest practices · production · operations
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