Reduce the number of Random number generation. SecureRandom is quite slow, so within the same milliseconds, just incrementing the randomness part will provide better performance. 2. Generate random in Array[Byte] (10 bytes = 80 bits). Regular Random uses 48-bit seed, so calling Random.nextInt (32 bits) x 3 is faster, but SecureRandom has optimization for Array[Byte] generation, which is much faster than calling nextInt three times. 3. ULIDs are often used in the string value form (e.g., transaction IDs, object IDs which can be embedded to URLs, etc.). Generating ULID String from the beginning is ideal. 4. In base32 encoding/decoding, use bit-shift operators as much as possible to utilize CPU registers and memory cache.