Databricks Placement Papers 2026
Databricks Placement Papers 2026 – Questions, Answers & Complete Interview Guide
Meta Description: Ace Databricks campus placements 2026 with real placement paper questions, Data Engineering & ML coding problems, system design tips, and HR interview prep. Freshers CTC: ₹30–50 LPA. Complete guide for Indian engineering students.
About Databricks
Databricks is the unified analytics platform for data engineering, machine learning, and collaborative data science, built on Apache Spark. Founded in 2013 by the creators of Apache Spark at UC Berkeley (Ali Ghodsi, Matei Zaharia, and team), Databricks has grown to a valuation exceeding $43 billion and is considered the gold standard for enterprise data and AI platforms. Its flagship product, the Databricks Lakehouse Platform, unifies data warehousing and AI/ML on a single, open architecture.
In India, Databricks has a growing engineering presence in Bengaluru, working on core platform components including the Spark runtime, Delta Lake (the open-source storage layer), MLflow (the open-source ML lifecycle management platform), and enterprise product features. Engineers at Databricks work on some of the most challenging distributed systems problems in the industry — processing petabytes of data, optimizing Spark query execution, and building ML infrastructure that scales.
Freshers can expect a CTC of ₹30 LPA to ₹50 LPA, which reflects the company's strong valuation and its competition with FAANG-tier companies for top engineering talent. The interview process is rigorous, with a strong emphasis on Data Structures, Algorithms, Python/Scala proficiency, and understanding of distributed computing concepts. Candidates with data engineering or ML engineering backgrounds are especially well-positioned.
Eligibility Criteria
| Parameter | Requirement |
|---|---|
| Degree | B.Tech / B.E. / M.Tech / Dual Degree / M.S. |
| Minimum CGPA | 8.0 / 10 strongly preferred |
| Active Backlogs | None |
| Historical Backlogs | None preferred |
| Graduation Year | 2026 batch |
| Eligible Branches | CSE, IT, ECE, Mathematics & Computing, Data Science |
| Skills Preferred | Python, Spark, SQL, distributed systems, ML basics |
Databricks Selection Process 2026
-
Resume Shortlisting – Databricks highly values open-source contributions (especially Spark, Delta Lake, MLflow), data engineering projects, and research publications. A Kaggle ranking or ML competition background helps significantly.
-
Recruiter Phone Screen – 30-minute conversation about background, technical interests, and why Databricks. The recruiter will probe data engineering knowledge at a surface level.
-
Online Technical Assessment – 2 coding problems on HackerRank/LeetCode-style platform. 90 minutes. Typically includes 1 medium and 1 medium-hard problem. Some assessments include a SQL query problem.
-
Technical Interview Round 1 (Coding) – 60-minute live coding interview. Problems often relate to data processing, string manipulation, or graph algorithms. Focus on clean, efficient code.
-
Technical Interview Round 2 (Data Engineering / Systems) – Discussion of data pipeline design, Spark concepts, SQL optimization, and distributed systems fundamentals. May include a whiteboard problem around data processing at scale.
-
Technical Interview Round 3 (ML or Platform) – Depending on the role: ML engineers get ML system design and model evaluation questions; platform engineers get deeper distributed systems questions.
-
Behavioral Interview – Focused on Databricks' values: customers first, quality, openness, and innovation. STAR format expected.
-
Final Offer – Reference checks and offer within 1–2 weeks of final round.
Exam Pattern
| Section | Questions | Time | Focus Area |
|---|---|---|---|
| Online Coding Assessment | 2–3 | 90 min | DS&A, possibly SQL |
| Live Coding Round 1 | 1–2 | 60 min | Data structures, algorithms |
| Live Coding Round 2 | 1–2 | 60 min | Optimization, correctness |
| Data/Systems Design | 1 problem | 45–60 min | Pipeline design, scalability |
| ML Systems (if applicable) | 1–2 questions | 45 min | Model lifecycle, MLflow |
| Behavioral | 4–5 questions | 30 min | Values, collaboration |
Practice Questions with Detailed Solutions
Aptitude / Analytical
Q1. A data pipeline processes 1 million records per hour. How many records can it process in 8 hours if throughput drops by 15% every 2 hours?
Solution:
- Hour 1–2: 1M/hr × 2 hrs = 2M
- Hour 3–4: 1M × 0.85 × 2 = 1.7M
- Hour 5–6: 1M × 0.85² × 2 = 1.445M
- Hour 7–8: 1M × 0.85³ × 2 = 1.228M
- Total ≈ 2 + 1.7 + 1.445 + 1.228 = 6.373M records
✅ Answer: ~6.37 million records
Q2. If a Spark job uses 20 executors each with 4 cores, and processes 800 partitions, what is the minimum number of waves needed?
Solution:
- Total parallel task capacity = 20 executors × 4 cores = 80 tasks simultaneously
- Waves needed = ⌈800 / 80⌉ = 10 waves
✅ Answer: 10 waves (This type of analytical question appears in Databricks technical screens)
Q3. A 2 TB dataset is stored in Parquet format with a 10:1 compression ratio. What was the original uncompressed size?
Solution:
- Compressed size = 2 TB
- Compression ratio = 10:1 → uncompressed = 2 × 10 = 20 TB
✅ Answer: 20 TB
Q4. In a sequence 1, 1, 2, 3, 5, 8, 13, 21, what is the ratio of the 10th term to the 9th term (Fibonacci)?
Solution:
- Fibonacci terms: 1, 1, 2, 3, 5, 8, 13, 21, 34, 55
- 9th term = 34, 10th term = 55
- Ratio = 55/34 ≈ 1.617 (Golden ratio φ)
✅ Answer: 55/34 ≈ 1.617
Q5. A SQL query without an index scans 10M rows in 5 seconds. After adding an index, it uses B-tree lookup: O(log n) vs O(n). Estimate new query time.
Solution:
- Without index: O(n) = 10M rows in 5s → each row unit = 5/10M = 0.0000005s
- With index: O(log 10M) ≈ O(23.25) steps
- Estimated time = 23.25 × 0.0000005 ≈ ~0.0000116 seconds (much faster in theory)
- In practice, index queries are 100x–1000x faster on large tables
✅ Key insight: Index reduces full scan to logarithmic lookup
Coding Questions
Q6. Word Count using MapReduce paradigm (Core Spark concept).
from collections import defaultdict
def word_count_mapreduce(documents):
"""
Simulate MapReduce word count.
Map phase: emit (word, 1) for each word
Reduce phase: sum counts per word
"""
# MAP phase
mapped = []
for doc in documents:
for word in doc.lower().split():
word = word.strip('.,!?')
mapped.append((word, 1))
# SHUFFLE & SORT (group by key)
grouped = defaultdict(list)
for word, count in mapped:
grouped[word].append(count)
# REDUCE phase
reduced = {word: sum(counts) for word, counts in grouped.items()}
return dict(sorted(reduced.items(), key=lambda x: x[1], reverse=True))
# Example
docs = [
"data engineering is powerful",
"data science and data engineering",
"apache spark powers data processing"
]
print(word_count_mapreduce(docs))
# PySpark equivalent:
# rdd = sc.parallelize(docs)
# result = rdd.flatMap(lambda x: x.split()) \
# .map(lambda word: (word, 1)) \
# .reduceByKey(lambda a, b: a + b)
Q7. Implement a simplified ETL pipeline with transformation and validation.
from typing import List, Dict, Optional
from datetime import datetime
class ETLPipeline:
def __init__(self):
self.errors = []
self.processed = 0
def extract(self, raw_data: List[Dict]) -> List[Dict]:
"""Extract: return raw records."""
return raw_data
def transform(self, records: List[Dict]) -> List[Dict]:
"""Transform: clean and normalize records."""
transformed = []
for record in records:
try:
# Normalize
cleaned = {
'user_id': str(record.get('user_id', '')).strip(),
'amount': float(record.get('amount', 0)),
'currency': record.get('currency', 'USD').upper(),
'timestamp': self._parse_timestamp(record.get('timestamp')),
'status': record.get('status', 'unknown').lower()
}
# Validate
if not cleaned['user_id']:
raise ValueError("Missing user_id")
if cleaned['amount'] <= 0:
raise ValueError(f"Invalid amount: {cleaned['amount']}")
transformed.append(cleaned)
self.processed += 1
except (ValueError, TypeError) as e:
self.errors.append({'record': record, 'error': str(e)})
return transformed
def _parse_timestamp(self, ts) -> Optional[datetime]:
if not ts:
return None
try:
return datetime.fromisoformat(str(ts))
except ValueError:
return None
def load(self, records: List[Dict]) -> Dict:
"""Load: simulate writing to Delta Lake / database."""
return {
'records_written': len(records),
'errors': len(self.errors),
'success_rate': f"{(self.processed / (self.processed + len(self.errors)) * 100):.1f}%"
}
def run(self, raw_data: List[Dict]) -> Dict:
extracted = self.extract(raw_data)
transformed = self.transform(extracted)
return self.load(transformed)
# Test
pipeline = ETLPipeline()
raw = [
{'user_id': 'u001', 'amount': 100.50, 'currency': 'usd', 'timestamp': '2026-03-01', 'status': 'SUCCESS'},
{'user_id': '', 'amount': 50, 'currency': 'inr', 'timestamp': '2026-03-02', 'status': 'failed'},
{'user_id': 'u003', 'amount': -10, 'currency': 'EUR', 'timestamp': '2026-03-03', 'status': 'success'},
]
result = pipeline.run(raw)
print(result) # {'records_written': 1, 'errors': 2, 'success_rate': '33.3%'}
Q8. Median of Two Sorted Arrays (O(log(m+n)) — Databricks loves this).
def find_median_sorted_arrays(nums1, nums2):
"""Binary search approach — O(log(min(m,n)))"""
if len(nums1) > len(nums2):
nums1, nums2 = nums2, nums1 # nums1 must be shorter
m, n = len(nums1), len(nums2)
left, right = 0, m
while left <= right:
i = (left + right) // 2 # Partition point in nums1
j = (m + n + 1) // 2 - i # Partition point in nums2
max_left1 = nums1[i-1] if i > 0 else float('-inf')
min_right1 = nums1[i] if i < m else float('inf')
max_left2 = nums2[j-1] if j > 0 else float('-inf')
min_right2 = nums2[j] if j < n else float('inf')
if max_left1 <= min_right2 and max_left2 <= min_right1:
if (m + n) % 2 == 0:
return (max(max_left1, max_left2) + min(min_right1, min_right2)) / 2
else:
return max(max_left1, max_left2)
elif max_left1 > min_right2:
right = i - 1
else:
left = i + 1
# Examples
print(find_median_sorted_arrays([1, 3], [2])) # 2.0
print(find_median_sorted_arrays([1, 2], [3, 4])) # 2.5
print(find_median_sorted_arrays([0, 0], [0, 0])) # 0.0
Q9. Implement a simple version of Delta Lake — ACID writes with versioning.
import copy
from typing import List, Dict, Any
class DeltaTable:
"""
Simplified Delta Lake: supports versioned, ACID writes.
Tracks transaction log and allows time travel.
"""
def __init__(self, name: str):
self.name = name
self.versions = {} # version -> list of records
self.current_version = 0
self.transaction_log = []
self.versions[0] = [] # Empty table at v0
def insert(self, records: List[Dict]) -> int:
"""Insert records and create a new version."""
new_version = self.current_version + 1
new_data = copy.deepcopy(self.versions[self.current_version])
new_data.extend(records)
self.versions[new_version] = new_data
self.current_version = new_version
self.transaction_log.append({
'version': new_version,
'operation': 'INSERT',
'record_count': len(records)
})
return new_version
def delete(self, condition_key: str, condition_value: Any) -> int:
"""Delete records matching condition — creates new version."""
new_version = self.current_version + 1
current_data = self.versions[self.current_version]
new_data = [r for r in current_data if r.get(condition_key) != condition_value]
self.versions[new_version] = new_data
self.current_version = new_version
self.transaction_log.append({
'version': new_version,
'operation': 'DELETE',
'condition': f"{condition_key}={condition_value}"
})
return new_version
def read(self, version: int = None) -> List[Dict]:
"""Read table at a specific version (time travel)."""
v = version if version is not None else self.current_version
return copy.deepcopy(self.versions.get(v, []))
def history(self) -> List[Dict]:
return self.transaction_log
# Test
table = DeltaTable("events")
v1 = table.insert([{"id": 1, "event": "login"}, {"id": 2, "event": "purchase"}])
v2 = table.insert([{"id": 3, "event": "logout"}])
v3 = table.delete("id", 2)
print(f"Current: {table.read()}") # 2 records (id 1 and 3)
print(f"At v1: {table.read(v1)}") # 2 records (id 1 and 2)
print(f"History: {table.history()}")
Q10. Top K Frequent Elements (Heap + HashMap).
import heapq
from collections import Counter
def top_k_frequent(nums, k):
count = Counter(nums)
return heapq.nlargest(k, count.keys(), key=count.get)
# Better: bucket sort for O(n) time
def top_k_frequent_optimal(nums, k):
count = Counter(nums)
buckets = [[] for _ in range(len(nums) + 1)]
for num, freq in count.items():
buckets[freq].append(num)
result = []
for i in range(len(buckets) - 1, 0, -1):
result.extend(buckets[i])
if len(result) >= k:
return result[:k]
return result
# Examples
print(top_k_frequent([1, 1, 1, 2, 2, 3], 2)) # [1, 2]
print(top_k_frequent([1], 1)) # [1]
Q11. SQL — Find the second highest salary (Classic SQL interview question).
-- Method 1: Using LIMIT with OFFSET
SELECT DISTINCT salary
FROM employees
ORDER BY salary DESC
LIMIT 1 OFFSET 1;
-- Method 2: Using subquery
SELECT MAX(salary) AS second_highest
FROM employees
WHERE salary < (SELECT MAX(salary) FROM employees);
-- Method 3: Using DENSE_RANK (preferred for Databricks/Spark SQL)
SELECT salary
FROM (
SELECT salary, DENSE_RANK() OVER (ORDER BY salary DESC) AS rnk
FROM employees
) ranked
WHERE rnk = 2
LIMIT 1;
-- Databricks SQL (using CTE)
WITH ranked AS (
SELECT salary,
DENSE_RANK() OVER (ORDER BY salary DESC) AS rnk
FROM employees
)
SELECT salary AS SecondHighestSalary
FROM ranked
WHERE rnk = 2;
Q12. Implement MLflow Experiment Tracking (conceptual + code).
# MLflow is Databricks' open-source ML lifecycle platform
# In interviews, you may be asked to design or implement simplified tracking
class ExperimentTracker:
"""Simplified MLflow-style experiment tracker."""
def __init__(self):
self.experiments = {}
self.current_run = None
def create_experiment(self, name: str) -> str:
exp_id = f"exp_{len(self.experiments):04d}"
self.experiments[exp_id] = {
'name': name,
'runs': {}
}
return exp_id
def start_run(self, experiment_id: str, run_name: str = None) -> str:
exp = self.experiments.get(experiment_id)
if not exp:
raise ValueError(f"Experiment {experiment_id} not found")
run_id = f"run_{len(exp['runs']):04d}"
exp['runs'][run_id] = {
'name': run_name or run_id,
'params': {},
'metrics': {},
'artifacts': [],
'status': 'RUNNING'
}
self.current_run = (experiment_id, run_id)
return run_id
def log_param(self, key: str, value):
exp_id, run_id = self.current_run
self.experiments[exp_id]['runs'][run_id]['params'][key] = value
def log_metric(self, key: str, value: float, step: int = None):
exp_id, run_id = self.current_run
metrics = self.experiments[exp_id]['runs'][run_id]['metrics']
if key not in metrics:
metrics[key] = []
metrics[key].append({'value': value, 'step': step})
def end_run(self, status: str = "FINISHED"):
exp_id, run_id = self.current_run
self.experiments[exp_id]['runs'][run_id]['status'] = status
self.current_run = None
# Usage — similar to real MLflow API
tracker = ExperimentTracker()
exp_id = tracker.create_experiment("fraud_detection_v1")
run_id = tracker.start_run(exp_id, "xgboost_baseline")
tracker.log_param("n_estimators", 100)
tracker.log_param("max_depth", 5)
tracker.log_param("learning_rate", 0.1)
for epoch in range(3):
tracker.log_metric("train_auc", 0.85 + epoch * 0.02, step=epoch)
tracker.log_metric("val_auc", 0.83 + epoch * 0.015, step=epoch)
tracker.end_run()
print(tracker.experiments[exp_id]['runs'][run_id])
Q13. Graph: Detect Cycle in a Directed Graph (relevant for DAG-based pipelines).
def has_cycle(graph):
"""
Detect cycle in directed graph using DFS + color marking.
0 = WHITE (unvisited), 1 = GRAY (in progress), 2 = BLACK (done)
Relevant: Spark uses DAG (Directed Acyclic Graph) for execution plans.
A cycle in a pipeline DAG means infinite execution.
"""
color = {node: 0 for node in graph}
def dfs(node):
color[node] = 1 # Mark as in-progress
for neighbor in graph.get(node, []):
if color[neighbor] == 1:
return True # Back edge = cycle
if color[neighbor] == 0:
if dfs(neighbor):
return True
color[node] = 2 # Mark as done
return False
for node in graph:
if color[node] == 0:
if dfs(node):
return True
return False
# Test
pipeline1 = {'A': ['B'], 'B': ['C'], 'C': ['D'], 'D': []} # No cycle (valid DAG)
pipeline2 = {'A': ['B'], 'B': ['C'], 'C': ['A']} # Cycle! (invalid)
print(has_cycle(pipeline1)) # False ✅
print(has_cycle(pipeline2)) # True ❌
Q14. Sliding Window Maximum (useful for time-series data in Spark streaming).
from collections import deque
def max_sliding_window(nums, k):
"""
Find maximum in each sliding window of size k.
Time: O(n), Space: O(k)
"""
dq = deque() # Monotonic decreasing deque (stores indices)
result = []
for i, num in enumerate(nums):
# Remove elements outside window
while dq and dq[0] < i - k + 1:
dq.popleft()
# Remove smaller elements (they'll never be maximum)
while dq and nums[dq[-1]] < num:
dq.pop()
dq.append(i)
if i >= k - 1:
result.append(nums[dq[0]])
return result
# Example
nums = [1, 3, -1, -3, 5, 3, 6, 7]
k = 3
print(max_sliding_window(nums, k)) # [3, 3, 5, 5, 6, 7]
Q15. Write a PySpark-style groupBy and aggregation.
# In an interview, you might be asked to simulate Spark's groupBy/agg behavior
from collections import defaultdict
from typing import List, Dict, Callable
def spark_groupby_agg(data: List[Dict], group_col: str,
agg_col: str, agg_fn: Callable) -> List[Dict]:
"""
Simulate Spark's: df.groupBy(group_col).agg(agg_fn(agg_col))
"""
groups = defaultdict(list)
for row in data:
key = row[group_col]
groups[key].append(row[agg_col])
return [
{group_col: key, f"{agg_fn.__name__}({agg_col})": agg_fn(values)}
for key, values in groups.items()
]
# Example data: sales by region
sales_data = [
{'region': 'North', 'revenue': 100},
{'region': 'South', 'revenue': 200},
{'region': 'North', 'revenue': 150},
{'region': 'South', 'revenue': 300},
{'region': 'East', 'revenue': 250},
]
result = spark_groupby_agg(sales_data, 'region', 'revenue', sum)
for row in result:
print(row)
# {'region': 'North', 'sum(revenue)': 250}
# {'region': 'South', 'sum(revenue)': 500}
# {'region': 'East', 'sum(revenue)': 250}
HR Interview Questions with Sample Answers
Q1. Why Databricks over other data companies?
"Databricks is at the intersection of the two most important trends in enterprise tech — cloud data infrastructure and AI/ML. What draws me specifically is that Databricks actually built and open-sourced Apache Spark and Delta Lake — they're not just using these tools, they're shaping the entire data ecosystem. I want to work where the most important technical decisions are being made. Also, the engineering culture prioritizes openness — open source, open data formats — which aligns with how I think good software should be built."
Q2. Tell me about a data engineering or ML project you've built.
"I built a sales forecasting pipeline for a college hackathon that won second place. I used Python and PySpark (on a local cluster) to clean and join two datasets — historical sales and marketing spend. I then trained an XGBoost model, tracked experiments with MLflow, and deployed the model with a FastAPI endpoint. The hardest part was handling missing values in time-series data — I implemented forward-fill with a lookback limit. The model achieved 87% accuracy on holdout data. That project made me want to work at a company where data pipelines are the product."
Q3. How do you approach debugging a slow Spark job?
"I start with the Spark UI — looking at the DAG visualization to identify bottlenecks. I check for data skew first (are some partitions much larger?), then look at the number of stages and shuffles. Shuffles are usually the biggest performance killer. If I see a skewed join, I might add salting. I also check for unnecessary wide transformations and see if I can replace them with broadcast joins for small tables. If memory is an issue, I look at executor heap usage and spill metrics."
Q4. Describe a situation where you had to learn something completely new under time pressure.
"Three days before my internship presentation, I realized our team's recommendation system needed to be refactored to handle cold-start users — something we hadn't planned for. I had never implemented collaborative filtering before. I spent two days reading papers and a practical tutorial, then implemented a simple ALS (Alternating Least Squares) model using Spark MLlib for existing users and a fallback popularity-based recommender for cold-start. It wasn't perfect, but it worked and the presentation went well. The key was scoping the problem to what I could actually implement in time."
Q5. Where do you see data engineering going in the next 5 years?
"I think the biggest shift will be the convergence of LLMs and data pipelines — what people are starting to call 'LLM Ops' or 'AI Engineering'. Instead of writing SQL or Spark code manually, engineers will increasingly use AI to generate and optimize pipelines. But the underlying infrastructure — Delta Lake, reliable streaming, data quality monitoring — becomes MORE important, not less, because AI systems need clean, reliable data to work. I'm excited to build that infrastructure layer."
Preparation Tips
- Learn Apache Spark fundamentals — RDDs, DataFrames, transformations vs actions, lazy evaluation, shuffles. These are Databricks' bread and butter.
- Master SQL — Complex joins, window functions, CTEs, query optimization. Databricks SQL is a first-class product, and SQL questions are common.
- Contribute to open source — Even small contributions to Delta Lake or MLflow repositories are noticed by Databricks recruiters.
- Practice on Databricks Community Edition — It's free. Build actual Spark notebooks, work with Delta tables, run MLflow experiments. Real-world experience shows.
- Understand the Lakehouse architecture — Know why it's better than a traditional data warehouse + data lake combo. Be able to explain it clearly.
- LeetCode Medium consistently — The coding bar is high. Practice arrays, graphs, DP, and sorting problems. Bonus: practice writing efficient Pandas code.
- Study distributed systems — Understand partitioning, fault tolerance, consistency models, and CAP theorem. These concepts come up in system design rounds.
Frequently Asked Questions (FAQ)
Q1. What is Databricks' fresher salary in India for 2026? Freshers at Databricks India can expect a total CTC of ₹30 LPA to ₹50 LPA, comprising base salary, RSUs (4-year vesting), and annual bonus. Top performers from IITs may receive the upper range.
Q2. What roles does Databricks hire freshers for in India? The primary fresher roles at Databricks India are Software Engineer (backend, platform, data infrastructure) and Solutions Engineer (customer-facing technical role). Data Scientist and ML Engineer roles also exist but may require a Master's degree.
Q3. Do I need to know Spark before applying to Databricks? While not strictly required, knowing PySpark gives you a significant advantage. Even basic familiarity — understanding what RDDs and DataFrames are, how transformations work — will make technical conversations much smoother. Databricks Community Edition is free to use for practice.
Q4. How important is open source contribution for getting into Databricks? More important here than almost anywhere else. Databricks was founded on open-source software and deeply values contributors. A few merged PRs to any Apache project (Spark, Flink, Kafka) or the Databricks ecosystem can be a significant differentiator.
Q5. Is MLflow knowledge required for Databricks interviews? For ML-focused roles, yes. For general SWE roles, conceptual understanding is sufficient. You should know what MLflow does (experiment tracking, model registry, model serving) and why it matters, even if you haven't used it extensively.
Last updated: March 2026 | Tags: Databricks Placement Papers 2026, Databricks Interview Questions India, Databricks Fresher Salary India, Data Engineering Jobs India 2026, Apache Spark Interview Questions
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