What are advantages of streams.

0-2 years experience

1. 1You need to read a 200 MB CSV file and process each line without loading the whole file into memory. How would you use Node.js streams to implement this?
2. 2If you pipe a readable stream into a writable stream and the writable stream encounters an error, what happens to the readable stream and how should you handle it?
3. 3What is the practical difference between using `fs.readFile` and creating a read stream for a large file, in terms of memory usage and latency?

2-5 years experience

1. 1Your service streams video data from disk to an HTTP response, but under load you notice occasional buffering and high memory usage. Walk me through how you would diagnose and fix the issue using stream features.
2. 2You added a Transform stream to compress data before sending it to an external API, but the downstream API sometimes returns 429 errors. How would you adjust your stream pipeline to respect backpressure?
3. 3Explain why mixing async functions with streams can cause the pipeline to break, and how you would refactor it for reliable flow control.

5-8 years experience

1. 1Design a data ingestion pipeline that reads from a Kafka topic, transforms records, and writes to S3, all using Node.js streams. Discuss how you would handle backpressure, fault tolerance, and scaling.
2. 2Your microservice processes uploaded files using streams, but a bug causes the process to hang when a client aborts the upload. How would you redesign the stream handling to ensure resources are released promptly?
3. 3Compare using Node.js streams versus a message queue for passing large payloads between services. What trade‑offs influence your choice at scale?

8+ years experience

1. 1Our platform is migrating legacy file‑processing jobs that use `fs.readFile` into a streaming architecture. What architectural considerations, testing strategies, and migration steps would you propose to minimize risk?
2. 2Across multiple teams, some services use native streams while others rely on third‑party libraries that wrap streams. How would you establish a unified streaming strategy and enforce consistency while allowing flexibility?
3. 3Looking ahead, how would you evolve a streaming‑based data pipeline to support schema evolution and real‑time analytics without disrupting existing consumers?