Question 1

What are your strengths and weaknesses?

Accepted Answer

Strengths: (1) Technical depth in Spark/SQL/Cloud—I design for scale and cost. (2) Problem-solving and analytical thinking—I use data to drive decisions. (3) Collaboration and communication—I bridge technical and business stakeholders. Weaknesses: (1) I sometimes take on too much—I'm working on delegating and saying no. (2) I can be a perfectionist—I'm learning to ship MVP and iterate. (3) Public speaking—I'm attending workshops and doing more internal tech talks....

Question 2

What is your biggest failure, and what did you learn from it?

Accepted Answer

Situation: I led a project that failed to meet its goals due to poor requirement gathering and lack of stakeholder alignment. We delivered 'on spec' but it wasn't what the business needed. Task: Own the failure and fix the underlying process. Action: I took full responsibility and ran a post-mortem. I identified gaps: unclear success criteria, infrequent stakeholder check-ins, no early validation....

Question 3

Identify the Unix command that lists files with specific permissions

Accepted Answer

**Command:** find . -perm 644. Or -perm -u=r for user read. find . -type f -perm 755. stat for single file. **Format:** rwx rwx rwx (owner group other). **Why:** Permission audit. **Production:** Combine with -exec.

Question 4

Write pseudo code for an ETL pipeline using Python and Pandas

Accepted Answer

**E:** Read source (CSV, API, DB). **T:** dropna, cast types, filter, derive columns, validate. **L:** to_sql, to_parquet. Add: logging, error handling, idempotency (overwrite by date), incremental (filter by watermark)....

Question 5

Design a relational data model for a sales database, incorporating normalization techniques

Accepted Answer

**Section 1 — The Context (The 'Why')**
The primary challenge for this design in SQL is balancing scale, cost, and reliability. At scale, naive approaches fail: single points of failure cause cascades, schema evolution breaks consumers, and over-provisioning explodes cost. Failure modes include silent data loss from non-idempotent writes, cascading job failures from tight coupling, and operational burden from manual intervention....

Question 6

Given two tables, calculate the row count for different types of joins (inner, left, right, and full outer)

Accepted Answer

Given |A|=a, |B|=b, |matches|=m: **Inner** = m. **Left** = a. **Right** = b. **Full outer** = a + b - m. **SQL**: SELECT 'inner', COUNT(*) FROM a INNER JOIN b ON ... UNION ALL SELECT 'left', COUNT(*) FROM a LEFT JOIN b ON ......

Question 7

What motivates you to join Morgan Stanley?

Accepted Answer

**Situation**: Context of the challenge. **Task**: Your responsibility. **Action**: Specific steps, tools, collaboration. **Result**: Quantified outcome. Morgan Stanley's leadership in financial services and technology is compelling. The firm's scale—data across markets, risk, and clients—presents complex engineering challenges....

Question 8

Write a SQL query to calculate the highest salary in each department using a window function

Accepted Answer

SELECT department_id, employee_id, salary, MAX(salary) OVER (PARTITION BY department_id) AS max_salary FROM employees. Or with RANK: SELECT * FROM (SELECT *, RANK() OVER (PARTITION BY department_id ORDER BY salary DESC) r FROM employees) WHERE r = 1. **Why window**: Avoid correlated subquery; single pass....

Morgan Stanley Data Engineer Interview Questions

+12 More Questions with Expert Answers

Other Companies

Morgan Stanley Data Engineer Interview Questions

+12 More Questions with Expert Answers

Other Companies