Technical screening questions
Ask for one example per question and listen for specifics.
- What are case classes and pattern matching? A good answer: Immutable data types and concise branching.
- How do you handle absent values? A good answer: Option instead of null.
- How do you tune a Spark job in Scala? A good answer: Partitions, shuffles and caching.
- How do you handle concurrency? A good answer: Futures, Akka or effect libraries.
- What is a for-comprehension? A good answer: Sugar over map and flatMap chains.
Quick screening questions
Use these when you have only a few minutes.
- Which Scala libraries and versions did you use last?
- How do you model errors without exceptions?
- Describe a Spark job you tuned.
What separates the levels
Match the level to the requirement before you submit.
- Junior: implements features in an existing codebase.
- Mid: designs components and tests.
- Senior: sets architecture and style.
Red flags
Any of these is a reason to probe further.
- Writes Java-style Scala.
- No Spark exposure for a data role.
- Cannot explain Option.
Tools you should hear mentioned
A Scala developer with real experience usually names several of these without prompting.
- Scala
- Spark
- sbt
- Akka or Cats
- ScalaTest
- Kafka
Run the call well
Ask for the last project first, then dig into the second or third question. Take notes on versions, team size and outcomes, and record them with the submission so the vendor’s later technical interview does not surprise you.
Frequently asked questions
How long should a Scala developer screening call take?
Fifteen to twenty minutes is enough to cover the project, three technical questions and availability, rate and work authorization.
Do recruiters need to know the technology?
Working vocabulary is enough. Use the sourcing guide for the role and listen for specifics instead of judging technical depth yourself.