LinkedIn Interview Guide 2026: Social Graph Engineering, Data Systems, and Professional Network Scale
LinkedIn operates the world’s largest professional network with 1B+ members. Their engineering challenges center on social graph queries at scale, feed ranking, job matching ML, and real-time notifications. This guide covers SWE interviews from Staff E4 through Staff E6.
The LinkedIn Interview Process
- Recruiter screen (30 min)
- Technical phone screen (1 hour) — 1–2 coding problems
- Onsite (4–5 rounds):
- 2× coding (LeetCode-style, medium-hard)
- 1× system design (feed, search, messaging, or graph)
- 1× hiring manager / values alignment
- 1× (for senior) cross-functional leadership discussion
LinkedIn acquired by Microsoft in 2016; culture blends LinkedIn’s original startup DNA with Microsoft’s enterprise rigor. Expect questions about impact measurement and data-driven decisions.
Core Algorithms: Graph Problems
LinkedIn’s core data structure is the social graph. Expect graph traversal, shortest paths, and degree-of-separation queries.
Second-Degree Connection Discovery
from collections import defaultdict, deque
from typing import Set, Dict, List
class ProfessionalGraph:
"""
Social graph operations used in LinkedIn's "People You May Know" feature.
LinkedIn's actual graph has 1B+ nodes; uses distributed graph databases
(Voldemort, Espresso) with sharding by member ID.
"""
def __init__(self):
self.adjacency = defaultdict(set) # member_id -> set of connection_ids
def add_connection(self, a: int, b: int):
self.adjacency[a].add(b)
self.adjacency[b].add(a)
def get_connections(self, member_id: int, degree: int) -> Dict[int, int]:
"""
BFS to find all connections within `degree` hops.
Returns {member_id: distance} dict.
Time: O(V + E) in the local neighborhood
Space: O(V) visited set
"""
visited = {member_id: 0}
queue = deque([member_id])
while queue:
current = queue.popleft()
current_dist = visited[current]
if current_dist >= degree:
continue
for neighbor in self.adjacency[current]:
if neighbor not in visited:
visited[neighbor] = current_dist + 1
queue.append(neighbor)
visited.pop(member_id) # exclude self
return visited
def people_you_may_know(
self,
member_id: int,
limit: int = 20
) -> List[tuple]:
"""
Suggest connections based on mutual connections count.
Algorithm:
1. Get all 2nd-degree connections (friends-of-friends not yet connected)
2. Score by mutual connection count
3. Return top-K by score
Time: O(D1 * D2) where D1, D2 are avg degrees of 1st/2nd degree nodes
"""
direct = self.adjacency[member_id]
mutual_counts = defaultdict(int)
for friend in direct:
for friend_of_friend in self.adjacency[friend]:
if friend_of_friend != member_id and friend_of_friend not in direct:
mutual_counts[friend_of_friend] += 1
suggestions = [(count, person)
for person, count in mutual_counts.items()]
suggestions.sort(reverse=True)
return [(person, count) for count, person in suggestions[:limit]]
def shortest_path(self, source: int, target: int) -> List[int]:
"""
BFS shortest path between two members.
LinkedIn's "How You're Connected" feature.
Time: O(V + E)
Space: O(V)
"""
if source == target:
return [source]
parent = {source: None}
queue = deque([source])
while queue:
current = queue.popleft()
for neighbor in self.adjacency[current]:
if neighbor not in parent:
parent[neighbor] = current
if neighbor == target:
# Reconstruct path
path = []
node = target
while node is not None:
path.append(node)
node = parent[node]
return path[::-1]
queue.append(neighbor)
return [] # no path
Job Recommendation with Skill Matching
class JobMatcher:
"""
Simplified job recommendation using TF-IDF skill matching.
LinkedIn's actual system uses Graph Neural Networks and
feature-rich ML models with 100s of signals.
Key signals: skill overlap, title match, location, seniority,
company size preference, salary range, commute distance.
"""
def __init__(self):
self.jobs = {} # job_id -> {required_skills, title, level, salary}
def add_job(self, job_id: int, required_skills: List[str],
title: str, level: str, min_salary: int):
self.jobs[job_id] = {
'skills': set(s.lower() for s in required_skills),
'title': title.lower(),
'level': level,
'min_salary': min_salary,
}
def score_match(
self,
member_skills: List[str],
desired_salary: int,
desired_level: str,
job_id: int
) -> float:
"""
Score how well a job matches a member's profile.
Returns score in [0, 1].
"""
job = self.jobs[job_id]
member_skill_set = set(s.lower() for s in member_skills)
# Skill overlap (Jaccard similarity)
intersection = member_skill_set & job['skills']
union = member_skill_set | job['skills']
skill_score = len(intersection) / len(union) if union else 0
# Level match
level_score = 1.0 if job['level'] == desired_level else 0.5
# Salary fit
if job['min_salary'] <= desired_salary * 1.1:
salary_score = 1.0
elif job['min_salary'] List[tuple]:
scores = [
(self.score_match(member_skills, desired_salary, desired_level, jid), jid)
for jid in self.jobs
]
scores.sort(reverse=True)
return [(jid, score) for score, jid in scores[:limit]]
System Design: LinkedIn Feed
Common question: “Design LinkedIn’s news feed.”
Fan-Out Strategies
"""
LinkedIn Feed Architecture:
Two approaches to fan-out:
1. Fan-out on Write (Push model):
- When Alice posts, immediately write to all her followers' feeds
- Pro: Fast reads (pre-computed)
- Con: Expensive for members with 10K+ connections (celebrities)
2. Fan-out on Read (Pull model):
- When Bob opens feed, pull recent posts from all connections
- Pro: No wasted write work for inactive users
- Con: Slow read, O(connections * posts_per_person)
LinkedIn uses HYBRID:
- Regular users ( float:
"""
Multi-factor post scoring for feed ranking.
post: {engagement_rate, author_connection_degree,
topics, posted_at, sponsored}
"""
import math
# 1. Recency score (exponential decay)
hours_old = (current_time - post['posted_at']) / 3600
recency = math.exp(-hours_old / self.recency_half_life_hours)
# 2. Engagement score (predicted based on similar posts)
engagement = post.get('predicted_engagement_rate', 0.05)
# 3. Social proximity (1st degree > 2nd degree > 3rd degree)
proximity_weights = {1: 1.0, 2: 0.6, 3: 0.3, 0: 0.2}
proximity = proximity_weights.get(post.get('author_connection_degree', 0), 0.1)
# 4. Topic relevance
viewer_topics = set(viewer_profile.get('interests', []))
post_topics = set(post.get('topics', []))
topic_overlap = len(viewer_topics & post_topics) / max(len(viewer_topics | post_topics), 1)
# 5. Sponsored content gets score cap
if post.get('sponsored'):
return min(0.3, 0.15 * recency + 0.1 * engagement)
return (0.35 * recency + 0.30 * engagement +
0.20 * proximity + 0.15 * topic_overlap)
LinkedIn-Specific Technical Topics
- Voldemort: LinkedIn’s distributed key-value store (open source); used for member profiles, connections
- Kafka: Open-sourced by LinkedIn; used for activity streams, notifications, audit logs
- Espresso: Document store for mutable data with ACID transactions
- Pinot: Real-time analytics at LinkedIn (who viewed your profile counts)
- Venice: Derived data store fed by Kafka for fast read serving
Behavioral Questions at LinkedIn
- “How have you created economic opportunity for others?” — LinkedIn’s mission; connect your work to job market impact
- Ownership and initiative: Examples of driving projects without being asked
- Data-driven decision making: How you’ve used metrics to guide engineering decisions
- Collaboration across orgs: LinkedIn has many teams; cross-functional work matters
Compensation (E4–E6, US, 2025 data)
| Level | Title | Base | Total Comp |
|---|---|---|---|
| E4 | SWE | $180–210K | $250–330K |
| E5 | Senior SWE | $210–250K | $340–450K |
| E6 | Staff SWE | $250–300K | $460–620K |
LinkedIn (Microsoft subsidiary) RSUs are in Microsoft stock, which provides stability. Vest quarterly over 4 years.
Interview Tips
- Use LinkedIn: Understand the feed, search, InMail, job recommendations as a power user
- Graph algorithms: BFS/DFS, Dijkstra, topological sort — all relevant to social graph problems
- Read LinkedIn Engineering Blog: engineering.linkedin.com has deep posts on their systems
- Know Kafka deeply: LinkedIn invented it; knowing producer/consumer groups, partition design is a plus
- SQL and analytics: LinkedIn uses heavy analytics; complex window functions, CTEs are fair game
Practice problems: LeetCode 133 (Clone Graph), 684 (Redundant Connection), 1334 (Find the City), 547 (Number of Provinces).
Related System Design Interview Questions
Practice these system design problems that appear in LinkedIn interviews:
- Design a News Feed (Facebook-style)
- Design a Recommendation Engine (Netflix-style)
- System Design: Notification System (Push, Email, SMS)
- System Design: Search Autocomplete (Google Typeahead)
Related Company Interview Guides
- Airbnb Interview Guide 2026: Search Systems, Trust and Safety, and Full-Stack Engineering
- Vercel Interview Guide 2026: Edge Computing, Next.js Infrastructure, and Frontend Performance
- Netflix Interview Guide 2026: Streaming Architecture, Recommendation Systems, and Engineering Excellence
- Coinbase Interview Guide
- Figma Interview Guide 2026: Collaborative Editing, Graphics, and Real-Time Systems
- Meta Interview Guide 2026: Facebook, Instagram, WhatsApp Engineering
- System Design: Apache Kafka Architecture
- System Design: Distributed Cache (Redis vs Memcached)
- System Design: Rate Limiter
- Machine Learning System Design: Ranking and Recommendations
- System Design: Social Network at Scale
- System Design: Search Autocomplete / Typeahead
- System Design: Web Crawler (Google Search Indexing)
- System Design: Data Pipeline and ETL System (Airflow / Spark)
- System Design: Distributed Task Queue (Celery / SQS / Sidekiq)
- System Design: Code Repository and CI/CD (GitHub / GitLab)
- System Design: Fraud Detection System
- System Design: Ride-Sharing App (Uber / Lyft)
- System Design: Video Conferencing (Zoom / Google Meet)
- System Design: Real-Time Bidding Platform
- System Design: Database Replication and High Availability
- System Design: Machine Learning Training Infrastructure
- System Design: Serverless Architecture and FaaS
- System Design: Zero-Downtime Deployments
- System Design: Data Warehouse and OLAP Architecture
- System Design: Service Mesh and Microservice Communication
- System Design: Log Aggregation and Observability Pipeline
- System Design: Search Engine and Elasticsearch Internals
- System Design: Social Graph and Friend Recommendations
- System Design: Content Moderation at Scale
Explore all our company interview guides covering FAANG, startups, and high-growth tech companies.
Related system design: System Design Interview: Design a Hotel Booking System (Airbnb)
Related system design: Monotonic Stack Patterns: Complete Interview Guide (2025)
Related system design: System Design Interview: API Rate Limiter Deep Dive (All Algorithms)
Related system design: System Design Interview: Design a Distributed File System (HDFS/GFS)
Related system design: System Design Interview: Design Dropbox / Google Drive (Cloud Storage)
Related system design: Low-Level Design: Library Management System (OOP Interview)
Related system design: System Design Interview: Design a Distributed Messaging System (Kafka)
Related system design: String Manipulation Interview Patterns: Complete Guide (2025)
See also: System Design Interview: Design a Pastebin / Code Snippet Service
See also: System Design Interview: Design a Maps and Navigation System (Google Maps)
See also: Object-Oriented Design Patterns for Coding Interviews
See also: System Design Interview: Design a Feature Flag System
Related System Design Topics
📌 Related System Design: Low-Level Design: Chess Game (OOP Interview)
📌 Related System Design: Database Sharding: Complete System Design Guide
📌 Related: System Design Interview: Design Instagram / Photo Sharing Platform
📌 Related: System Design Interview: Design WhatsApp / Real-Time Messaging
📌 Related: System Design Interview: Design an E-Commerce Platform (Amazon-Scale)
📌 Related: System Design Interview: Design Twitter / X Timeline
📌 Related: Graph Traversal Interview Patterns (2025)
📌 Related: Low-Level Design: Chat Application (OOP Interview)
📌 Related: System Design Interview: Design a Social Media News Feed
📌 Related: System Design Interview: Design a Distributed Message Queue (Kafka)
📌 Related: Low-Level Design: Pub/Sub Event System (OOP Interview)
📌 Related: Low-Level Design: Task Scheduler / Job Queue (OOP Interview)
📌 Related: System Design Interview: Design a Distributed Search Engine
📌 Related: Low-Level Design: Notification System (OOP Interview)
📌 Related: Low-Level Design: Logging Framework (OOP Interview)
📌 Related: Low-Level Design: Library Management System (OOP Interview)
📌 Related: System Design Interview: Design a Search Autocomplete (Typeahead)
📌 Related: Low-Level Design: Online Auction System (OOP Interview)
📌 Related: Low-Level Design: Stock Order Book (Trading System OOP Interview)
📌 Related: Low-Level Design: Social Network Friend Graph (OOP Interview)
Related system design: Low-Level Design: Vending Machine (State Pattern OOP Interview)
Related system design: Low-Level Design: Elevator System (SCAN, Dispatch, State Machine)
Related system design: Union-Find (DSU) Interview Patterns: Connected Components, MST, Kruskal
Related: System Design: Feature Flag and A/B Testing System
Related system design: Sliding Window Interview Patterns: Fixed, Variable, Deque (2025)
Related system design: Two Pointers Interview Patterns: Two Sum, 3Sum, Cycle Detection (2025)
Related system design: Dynamic Programming Interview Patterns: Knapsack, LCS, Interval DP (2025)
Related system design: Low-Level Design: Social Media Feed (Follow, Post, Fan-out, Likes)
Related system design: Stack Interview Patterns: Monotonic Stack, Calculator, Min Stack (2025)
Related system design: System Design: Apache Kafka — Architecture, Partitions, and Stream Processing
Related system design: System Design: Collaborative Document Editing (Google Docs) — OT, CRDT, and WebSockets
Related system design: System Design: Distributed Counters, Leaderboards, and Real-Time Analytics
Related system design: System Design: Real-time Chat and Messaging System (WhatsApp/Slack) — WebSockets, Pub/Sub, Scale
Related system design: Matrix Interview Patterns: BFS/DFS on Grids, Island Count, Shortest Path (2025)
Related system design: Sorting Algorithms Interview Patterns: Merge Sort, Quick Sort, Heap Sort, Counting Sort (2025)
Related system design: Trie Interview Patterns: Autocomplete, Word Search, Prefix Matching (2025)
Related system design: Low-Level Design: Social Media Post Scheduler — Scheduling, Multi-Platform Publishing, and Analytics
Related system design: String Sliding Window Interview Patterns: Longest Substring, Anagram, Minimum Window (2025)
Related system design: 2D Dynamic Programming Interview Patterns: LCS, Edit Distance, Knapsack, Grid Paths (2025)
Related system design: Low-Level Design: Employee Leave Management System — Accrual, Approval Workflows, Balances, and Compliance
Related system design: Low-Level Design: Task Management System — Boards, Workflows, Assignments, Due Dates, and Notifications
Related system design: Advanced Tree Interview Patterns: Segment Trees, Fenwick Trees, Trie Operations, BST Validation (2025)
Related system design: System Design: Social Network News Feed — Fan-out on Write vs Read, Ranking, and Feed Generation
Related system design: System Design: Typeahead and Search Autocomplete — Trie, Prefix Indexing, and Real-time Suggestions
Related system design: Advanced Graph Algorithms Interview Patterns: Bellman-Ford, Floyd-Warshall, Kruskal MST, Tarjan SCC (2025)
Related system design: Low-Level Design: Document Management System — Versioning, Permissions, Full-text Search, and Collaboration
Related system design: String Matching Algorithm Interview Patterns: KMP, Rabin-Karp, Z-Algorithm, and Boyer-Moore (2025)
Related system design: Dynamic Programming on Graphs: Shortest Path DP, DAG DP, and Tree DP (2025)
Related system design: Randomized Algorithms Interview Patterns: Reservoir Sampling, QuickSelect, Skip Lists (2025)
Related system design: Amortized Analysis Interview Patterns: Dynamic Arrays, Stack Operations, and Union-Find (2025)
Related system design: System Design: ML Feature Store — Feature Computation, Storage, Serving, and Point-in-Time Correctness
Related system design: System Design: Distributed Message Queue — Kafka Architecture, Partitions, Consumer Groups, and Delivery Guarantees
Related system design: Low-Level Design: Social Media Platform — Posts, Feeds, Follows, and Notifications
Related system design: Number Theory Interview Patterns: GCD, Sieve of Eratosthenes, Fast Exponentiation, and Modular Arithmetic (2025)
Related system design: Topological Sort and Strongly Connected Components: Interview Patterns for Directed Graphs (2025)
Related system design: System Design: Chat Application — Real-Time Messaging, Message Storage, and Presence (WhatsApp/Slack)
Related system design: Palindrome Dynamic Programming Interview Patterns: LPS, Minimum Cuts, and Palindrome Partitioning (2025)
Related system design: Greedy Algorithm Interview Patterns: Activity Selection, Jump Game, and Interval Scheduling (2025)
Related system design: System Design: Typeahead and Autocomplete — Trie, Ranking, and Real-Time Suggestion Updates
Related system design: Tree DP and Path Problems: Maximum Path Sum, Diameter, LCA, and Serialization (2025)
Related system design: Divide and Conquer Interview Patterns: Merge Sort Variants, Count Inversions, and Closest Pair (2025)
Related system design: Longest Increasing Subsequence (LIS): DP and Binary Search Interview Patterns (2025)
Related system design: Merge Intervals Interview Patterns: Overlapping Intervals, Meeting Rooms, Calendar Problems (2025)
Related system design: System Design: Ad Server — Targeting, Real-Time Bidding, Impression Tracking, and Click Attribution
Related system design: Math Interview Patterns: Prime Sieve, Fast Power, GCD, and Combinatorics (2025)
Related system design: Low-Level Design: Online Learning Platform (Coursera/Udemy) — Courses, Progress, and Certificates
Related system design: Graph BFS Interview Patterns: Shortest Path, Islands, Word Ladder, and Multi-Source BFS (2025)
Related system design: String Hashing Interview Patterns: Rabin-Karp, Rolling Hash, and Polynomial Hashing (2025)
Related system design: Low-Level Design: Task Management System (Trello/Jira) — Boards, Workflows, and Notifications
Related system design: Dynamic Programming Patterns: Recognizing and Solving DP Problems (Complete Guide 2025)
Related system design: Tree Traversal Interview Patterns: Inorder, Level Order, Zigzag, and Serialize/Deserialize (2025)
Related system design: DP on Trees Interview Patterns: Subtree DP, Rerooting, and Path Aggregation (2025)
Related system design: Low-Level Design: Collaborative Document Editor — Operational Transform, CRDT, and Conflict Resolution
Related system design: System Design: Search Ranking — Query Processing, Inverted Index, and Relevance Scoring
Related system design: Low-Level Design: Calendar App — Event Scheduling, Recurring Events, and Conflict Detection
Related system design: Union-Find (Disjoint Set Union) Interview Patterns: Path Compression, Connectivity, and Advanced Problems (2025)
Related system design: Low-Level Design: CRM System — Contact Management, Pipeline Tracking, and Activity Logging
Related system design: Low-Level Design: Job Board Platform — Job Listings, Search, Applications, and Recruiter Workflow
Related system design: String Algorithm Interview Patterns: KMP, Rabin-Karp, Z-Function, and Trie Applications (2025)
Related system design: System Design: Typeahead / Search Autocomplete — Trie Service, Ranking, and Low-Latency Delivery
See also: Low-Level Design: Inventory Management System
See also: Low-Level Design: Warehouse Management System
See also: Low-Level Design: Online Judge System
See also: System Design: Analytics Dashboard
See also: Low-Level Design: Library Management System
See also: Advanced Interval Interview Patterns
See also: Low-Level Design: Banking System
See also: Low-Level Design: Stock Trading Platform
See also: Low-Level Design: Issue Tracker
See also: Two Pointers Interview Patterns
See also: System Design: Feed Ranking and Personalization
See also: Low-Level Design: Content Management System
See also: String Manipulation Interview Patterns
See also: Low-Level Design: Poll and Voting System
LinkedIn system design interviews include poll and survey features. Review the full LLD in Survey Builder Low-Level Design.
LinkedIn interviews test graph algorithms for network analysis. Review advanced patterns in Advanced Graph Algorithm Interview Patterns.
LinkedIn’s Economic Graph uses knowledge graph principles. Review the full system design in Knowledge Graph System Design.
LinkedIn interviews include string algorithm problems. Review KMP and rolling hash patterns in String Search Algorithm Interview Patterns.
LinkedIn interviews test bit manipulation. Review advanced patterns in Advanced Bit Manipulation Interview Patterns.
LinkedIn interviews include graph and cycle problems. Review Floyd’s and Union-Find patterns in Graph Cycle Detection Interview Patterns.
LinkedIn system design covers real-time collaboration. Review OT and CRDT patterns in Collaborative Document Editing System Design.
LinkedIn system design covers professional feed personalization. Review the full LLD in Social Feed System Low-Level Design.
See also: Low-Level Design: Code Review Tool – Diffs, Comments, Approvals, and CI Integration (2025)
LinkedIn system design covers enterprise access control. Review RBAC, ABAC, and ReBAC patterns in Access Control System Low-Level Design.
LinkedIn interviews test graph algorithms. Review shortest path patterns for social and routing graphs in Graph Shortest Path Interview Patterns.
LinkedIn tests string search patterns. Review trie insert, prefix, and Word Search II in Trie Interview Patterns.
LinkedIn uses typeahead for people search. Review the full autocomplete LLD with ranking and scale in Search Autocomplete System Low-Level Design.
LinkedIn uses link tracking. Review URL shortener LLD with idempotency and analytics in URL Shortener System Low-Level Design.
LinkedIn built Kafka. Review message queue LLD including partitions, consumer groups, and compaction in Message Queue System Low-Level Design.
LinkedIn tests social graph traversal. Review BFS, connected components, and bipartite check in Graph Traversal Interview Patterns.
LinkedIn tests priority queue patterns. Review the median finder, top-K, and IPO two-heap in Advanced Heap Interview Patterns.
LinkedIn search indexes millions of profiles. Review inverted index, BM25 ranking, and sharding in Search Engine System Low-Level Design.
LinkedIn system design covers people search and autocomplete. Review the typeahead LLD in Typeahead Search (Autocomplete) System Low-Level Design.
LinkedIn system design covers professional social graph. Review the full LLD in Social Graph System Low-Level Design.
LinkedIn system design covers professional messaging. Review WebSocket routing and read receipts in Messaging System (Chat) Low-Level Design.
LinkedIn system design covers ad analytics pipelines. Review the click tracker LLD in Ad Click Tracker System Low-Level Design.
LinkedIn system design covers analytics pipelines at scale. Review the full LLD in Real-Time Analytics Platform Low-Level Design.
LinkedIn system design covers A/B testing infrastructure. Review the full experimentation platform LLD in A/B Testing Platform Low-Level Design.
LinkedIn system design covers large-scale analytics pipelines. Review the full LLD in Data Pipeline System Low-Level Design.
LinkedIn system design covers people search autocomplete. Review the full LLD in Search Suggestions (Autocomplete) System Low-Level Design.
LinkedIn system design covers email notifications. Review the full email delivery LLD in Email Delivery System Low-Level Design.
LinkedIn system design covers ML feature stores for recommendations. Review the full feature store LLD in Feature Store System Low-Level Design.
LinkedIn system design covers professional messaging. Review the chat system LLD in Chat System Low-Level Design (WhatsApp / Messenger).
LinkedIn system design covers full-text search indexing. Review the Elasticsearch design in Search Indexing System Low-Level Design.
Notification preference and DND system design is covered in our Notification Preferences System Low-Level Design.
Newsletter and email delivery system design is covered in our Newsletter System Low-Level Design.
Search history and activity tracking design is covered in our Search History System Low-Level Design.
Contact and address book system design is covered in our Address Book System Low-Level Design.
Activity feed system design is covered in our Activity Feed System Low-Level Design.
Waitlist and invite-based signup design is covered in our Waitlist System Low-Level Design.
Tagging and skill system design is covered in our Tagging System Low-Level Design.
Mentions and professional network notification design is covered in our Mentions and Notifications System Low-Level Design.
Online presence and status system design is covered in our Presence System Low-Level Design.
Faceted search and people search design is covered in our Faceted Search System Low-Level Design.
Feed pagination and cursor-based API design is covered in our Cursor Pagination Low-Level Design.
Change data capture and data pipeline reliability design is covered in our Change Data Capture (CDC) Low-Level Design.
API pagination and feed design is covered in our API Pagination Low-Level Design.
Bulk email campaign and user engagement design is covered in our Bulk Email Campaign System Low-Level Design.
Search suggestion and people search autocomplete design is covered in our Search Suggestion (Autocomplete) Low-Level Design.
Event replay and event sourcing system design is covered in our Event Replay Low-Level Design.
Notification dispatch and frequency cap system design is covered in our Notification Dispatch System Low-Level Design.
Scheduled notification and job alert delivery design is covered in our Scheduled Notification Low-Level Design.
Organization hierarchy and company structure design is covered in our Organization Hierarchy Low-Level Design.
Link preview and content sharing metadata design is covered in our Link Preview Service Low-Level Design.
Email verification and user onboarding security design is covered in our Email Verification Low-Level Design.
User presence and professional network status design is covered in our User Presence System Low-Level Design.
Follower graph and professional network design is covered in our Follower Graph Low-Level Design.
Trending topics and professional content trending design is covered in our Trending Topics Low-Level Design.
Content tagging and skill taxonomy design is covered in our Content Tagging System Low-Level Design.
Bookmark and saved content system design is covered in our Bookmark System Low-Level Design.
Poll and survey system design is covered in our Poll System Low-Level Design.
GDPR erasure and data privacy system design is covered in our GDPR Right to Erasure Low-Level Design.
Feature rollout and canary deployment design is covered in our Feature Rollout System Low-Level Design.
User onboarding and activation system design is covered in our User Onboarding System Low-Level Design.
Search index and full-text search system design is covered in our Search Index System Low-Level Design.
Invite system and professional network invitation design is covered in our Invite System Low-Level Design.
Email unsubscribe and notification preference design is covered in our Email Unsubscribe System Low-Level Design.
Activity feed aggregator and professional stream design is covered in our Activity Feed Aggregator Low-Level Design.
See also: Digest Email System Low-Level Design: Aggregation, Scheduling, Personalization, and Delivery
See also: Content Scheduler Low-Level Design: Scheduled Publishing, Timezone Handling, and Recurring Content
See also: Live Chat System Low-Level Design: WebSocket Connections, Message Persistence, and Presence
See also: Feature Flag Service Low-Level Design: Targeting Rules, Gradual Rollout, and Kill Switch
See also: Collaborative Document Editing Low-Level Design: OT, CRDT, Conflict Resolution, and Cursor Sync
See also: User Activity Feed Low-Level Design: Event Ingestion, Fan-Out, and Personalized Ranking
See also: Graph Search System Low-Level Design: Traversal, Index Structures, and Social Graph Queries
See also: Typeahead Autocomplete Low-Level Design: Trie Structure, Prefix Scoring, and Real-Time Suggestions
See also: Graph Database Low-Level Design: Native Graph Storage, Traversal Engine, and Cypher Query Execution
See also: Autocomplete Service Low-Level Design: Trie Storage, Prefix Scoring, and Personalization
See also: WebSocket Gateway Low-Level Design: Connection Management, Message Routing, and Horizontal Scaling
See also: Search Ranking System Low-Level Design: Relevance Scoring, Learning to Rank, and Feature Engineering
See also: Contact Book Service Low-Level Design: Contact Storage, Deduplication, and Group Management
See also: Survey and Forms System Low-Level Design: Dynamic Form Builder, Response Storage, and Analytics
See also: Search Suggest Low-Level Design: Trie Index, Personalization, and Sub-100ms Latency
See also: Typeahead Service Low-Level Design: Prefix Matching, Debounce, and Distributed Index
See also: Friend Recommendation Service Low-Level Design: Graph-Based Signals, Ranking, and Diversity
See also: Search Ranking Pipeline Low-Level Design: Query Understanding, Scoring Signals, and Re-ranking
See also: Search Quality Service Low-Level Design: Relevance Evaluation, Click Models, and Automated Testing
See also: Search Analytics Service Low-Level Design: Query Logging, Zero-Result Detection, and Click Analysis
See also: Digest Scheduler Low-Level Design: Aggregation Window, Priority Scoring, and Delivery Timing
See also: Search Personalization Service Low-Level Design: User History, Session Context, and Re-ranking
See also: Low Level Design: Presence Service
See also: A/B Testing Platform Low-Level Design
See also: Collaborative Filtering Service Low-Level Design: User-Item Matrix, ALS Training, and Online Serving
See also: Low Level Design: Content-Based Filtering Service
See also: Low Level Design: ETL Service
See also: Stream Processing Engine Low-Level Design: Windowing, Watermarks, and Exactly-Once Semantics
See also: Low Level Design: Social Graph Service
See also: User Profile Service Low-Level Design: Storage, Privacy Controls, and Partial Updates
See also: Low Level Design: Digest Email Service
See also: Low Level Design: Ranking System
See also: Low Level Design: Online Status Service
See also: Low Level Design: Search Filter and Faceting Service
See also: LLD Tag Test
See also: Low Level Design: User Follow / Subscribe Service
See also: Low Level Design: Newsletter Service
See also: Social Login System Low-Level Design
See also: Low Level Design: Leaderboard Service
See also: Low Level Design: Schema Registry
See also: Low Level Design: News Feed Service
See also: Low Level Design: Typing Indicator Service
See also: Low Level Design: Read Receipts Service
See also: Low Level Design: Streaming Analytics Service
See also: Low Level Design: Experiment Logging and Analysis Service