The JusDB Database Engineering Blog

MongoDB Atlas M30 costs 5.6x more than equivalent EC2 instances, but self-hosted TCO includes DBA labor that most comparisons ignore. Here's the honest math and when each option wins.

Design DynamoDB access patterns with composite keys, sparse GSIs, paginated queries, transactions, and evidence-based capacity planning.

Manage Elasticsearch indexes with ILM policies, correct shard sizing, and force merge for historical indices. Covers hot/warm/delete phases and cluster health monitoring.

Use Redis Streams for event sourcing and message queues. Covers XADD, XREADGROUP, consumer groups, XAUTOCLAIM for stale messages, and Python producer/consumer examples.

DynamoDB and MongoDB are the two most common NoSQL choices, but cost structures, query flexibility, and operational overhead differ dramatically depending on your access patterns.

MongoDB 8.0 brings significant replication improvements including faster elections, durable oplog writes, and changes to write concern behavior. Here's what changed and how to take advantage of it.

MongoDB indexes fragment over time as documents are inserted, updated, and deleted. Here's how to detect fragmentation, measure its performance impact, and rebuild indexes safely.

Day-to-day MongoDB replica set operations: adding/removing members, triggering elections, diagnosing replication lag, and managing oplog size.

An honest comparison of MongoDB and PostgreSQL in 2026 — document model vs relational model, JSONB as a document store, ACID transaction trade-offs, horizontal scaling, licensing, and migration paths.

MongoDB's flexible schema allows fields to be null, explicitly set to null, or simply absent — and these three states behave differently in queries, aggregations, and indexes.

Understand the Redis fork landscape after licensing changes. Compare Redis and Valkey features, licensing implications, migration paths, and community support.

Migrate from Redis to Valkey — compatibility, performance benchmarks, and what changes for operators