Redis Developer Certification Preparation

Launch a local Redis instance with Docker and use Redis CLI to execute and verify basic key commands.

Predict how Redis's in-memory, single-threaded command execution affects latency, throughput, and per-command atomicity in given scenarios.

Encode a basic Redis command and interpret its response using the Redis Serialization Protocol (RESP).

Initialize a TypeScript application with node-redis, connect it to Redis, execute commands, and interpret client-specific return values.

Handle node-redis error events and configure reconnection behavior for a simulated network interruption.

Implement graceful node-redis shutdown for normal application termination and process signals.

Select between a Redis String and Hash for a record based on whole-value reads, partial updates, serialization overhead, and memory trade-offs.

Predict Hash state and command return values after HSET operations, missing-key reads, missing-field reads, and removal of the last field.

Implement race-free Hash counters and conditional field creation using HINCRBY and HSETNX.

Design a colon-delimited key namespace that supports unambiguous SCAN patterns, debugging, and practical key-size constraints.

Select between a Hash and Redis JSON for flat or nested application data based on required read and update patterns.

Read nested values and array elements with JSONPath root, wildcard, index, and filter expressions, accounting for array-wrapped results.

Update or delete a nested value without rewriting an entire JSON document.

Apply JSON.MERGE to add, change, and null-delete multiple document fields in one operation.

Implement a capped, correctly ordered activity feed using List push commands and LTRIM, including behavior when the key is missing.

Implement uniqueness and membership analysis with Sets using SADD, SINTER, SUNION, and SUNIONSTORE, and predict their return values.

Build a leaderboard with Sorted Sets using ZADD, ZINCRBY, rank direction, and score-range queries.

Apply conditional ZADD options to preserve monotonic scores and distinguish member insertion from score updates.

Select a List, Set, or Sorted Set for a collection access pattern involving order, uniqueness, rank, or direct member removal.

Implement a cache-aside read path in Node.js/TypeScript with serialization, database fallback, cache population, and TTL.

Select an appropriate write-invalidation strategy and Redis eviction policy for a cache-aside production scenario.

Implement a collision-resistant cache for parameterized query results by encoding every result-affecting input in the key.

Select a cache-stampede mitigation using TTL jitter, stale-while-revalidate, or a lock built with SET NX EX for a given workload.

Predict a key's expiration state after sequences of reads and writes by applying TTL preservation and clearing rules and interpreting TTL or EXPIRETIME results.

Select RDB, AOF with an appropriate fsync policy, both, or no persistence based on data-loss tolerance, restart needs, and whether data is rebuildable.

Conduct a non-blocking Redis CLI audit using SCAN with MATCH and COUNT plus keyspace and key metadata inspection commands.

Choose and execute a safe cleanup strategy using DEL, UNLINK, multi-key deletion, or atomic RENAME based on value size and race risk.

Identify a time-of-check-to-time-of-use race in Redis application code and replace the read-then-write sequence with an appropriate atomic command such as SET NX.

Choose between node-redis pipelining and MULTI/EXEC based on round-trip and atomicity requirements, and predict the resulting response structure.

Implement bounded-retry optimistic locking in Node.js/TypeScript with WATCH and MULTI/EXEC for check-then-act logic.