As a Software Engineer at Sojern, you will be at the core of a high-performance engineering team that powers the travel industry's leading marketing platform. Sojern processes billions of real-time travel intent signals from global search and booking data to help brands reach travelers across multi-channel campaigns. In this role, you will build, scale, and optimize the backend services, real-time bidding systems, and data pipelines that make these complex advertising decisions in milliseconds.

The engineering team deals with massive scale and high-throughput infrastructure. Your work will directly impact the platform's reliability, latency, and ability to process complex data streams. Because Sojern relies heavily on data-driven decision-making, you will collaborate closely with data scientists, product managers, and database administrators to turn raw travel data into actionable advertising solutions.

This position requires a balance of strong algorithmic problem-solving, deep data literacy, and a practical approach to system design. It is an inspiring opportunity for engineers who enjoy working in a fast-paced environment where their code directly influences global travel commerce and real-time marketing efficiency.

The questions you will face during the Sojern hiring process are designed to evaluate your practical programming skills, your ability to manipulate data, and your collaborative mindset. These questions are drawn from real interview experiences and are grouped into key categories to help you identify patterns and focus your preparation.

Coding & Algorithms

These questions test your core computer science fundamentals, data structure choices, and ability to write clean, bug-free code under time constraints.

• How do you find a missing number between two arrays where one contains $n$ unique elements and the other contains $n-1$ of those same elements?
• Write a function to reverse a string or check if a string is a palindrome, optimizing for space complexity.

To succeed in the Sojern interview process, you must demonstrate both technical proficiency and a strong collaborative spirit. Your preparation should focus on the specific criteria the hiring team evaluates.

Role-Related Knowledge – You must show a deep understanding of your primary programming languages (such as Python) and database querying (SQL). You should be comfortable discussing data structures, memory management, and database optimization techniques.

Problem-Solving Ability – Interviewers want to see how you break down complex, ambiguous problems. Focus on explaining your thought process out loud, structuring your approach systematically, and discussing trade-offs before writing code.

System Design & Architecture – You should be prepared to design scalable systems that handle high throughput. Focus on data flow, database selection, caching strategies, and how to minimize latency in a distributed environment.

Culture & Collaboration – Sojern values friendly, communicative engineers who can articulate their ideas clearly. Be ready with structured behavioral stories that highlight your teamwork, adaptability, and passion for solving real-world business problems.

The interview process for a Software Engineer at Sojern is structured to thoroughly evaluate your technical capabilities and cultural fit over several stages. The process typically moves from initial conversational screens to a practical take-home challenge, culminating in a comprehensive virtual onsite panel.

The journey begins with a recruiter screen to discuss your background and align expectations, followed by a conversation with the hiring manager to dive deeper into your technical experience. If you pass these initial stages, you will receive a take-home assessment, usually in Python, to showcase your hands-on coding and problem-solving skills in a non-proctored environment.

The final stage is a multi-round panel interview. This panel is highly structured, typically consisting of dedicated rounds for SQL, Python live coding, System Design, and Behavioral evaluations with engineering leaders. Throughout the process, the interviewers are known to be friendly and collaborative, though the decision-making process can sometimes be highly competitive and thorough.

The timeline above outlines the typical progression from your initial application to the final hiring decision. Candidates should use this visual guide to pace their preparation, ensuring they allocate sufficient time to complete the take-home assessment before diving into intensive preparation for the multi-round panel.

To pass the technical bar at Sojern, you must perform consistently across several key evaluation areas. Each round of the panel interview targets a specific set of skills.

Python & Algorithmic Problem Solving

The live coding and take-home assessments evaluate your fluency in writing clean, efficient, and readable code. The difficulty level generally ranges from easy to medium, focusing on practical data manipulation rather than highly abstract or obscure algorithms.

Be ready to go over:

• Array and String Manipulation – Filtering, mapping, and searching through datasets efficiently.
• Time and Space Complexity – Discussing the Big O complexity of your code and optimizing it.
• Error Handling – Writing robust code that handles edge cases, null inputs, and unexpected data formats.
• Advanced concepts (less common) – Custom data structure implementations and memory-efficient generators in Python.

Example questions or scenarios:

• "Write a Python script to parse a log file of travel searches and output the most active users."
• "Implement an algorithm to find duplicates in an array of booking IDs without using extra space."

SQL & Database Querying

The database round is a core part of the onsite panel. You will be asked to write live queries to manipulate, filter, and aggregate relational data, reflecting the data-heavy nature of Sojern's travel marketing platform.

Be ready to go over:

• Joins and Subqueries – Combining multiple tables to extract meaningful business metrics.
• Aggregations and Filtering – Using functions like SUM, COUNT, AVG, and HAVING to slice data.
• Window Functions – Utilizing functions like ROW_NUMBER(), RANK(), or LEAD/LAG for sequential data analysis.
• Advanced concepts (less common) – Query optimization strategies, indexing, and analyzing execution plans.

Example questions or scenarios:

• "Write a query to calculate the month-over-month growth in travel bookings for each partner brand."
• "Given a table of user searches, find the users who searched for a flight more than three times but never made a booking."

System & Data Design

This round evaluates your ability to architect scalable systems and design clean data models. The focus is on practical, real-world scenarios rather than purely theoretical distributed systems.

Be ready to go over:

• Data Modeling – Designing relational and non-relational schemas to support specific application workflows.
• Scalability and Throughput – Handling high volumes of incoming search data without degrading system performance.
• API Design – Creating clean, intuitive RESTful or gRPC APIs for internal and external services.
• Advanced concepts (less common) – Caching layers, message queues (e.g., Kafka), and data warehousing solutions.

Example questions or scenarios:

• "Design the data storage and retrieval system for a real-time travel deals recommendation engine."
• "How would you design a system that ingests millions of travel search events per minute and makes them queryable with low latency?"

Behavioral & Leadership

The behavioral round, conducted by the hiring manager and engineering directors, assesses how you work in a team, manage project ambiguity, and align with Sojern's collaborative culture.

Be ready to go over:

• Project Walkthroughs – Explaining the business impact and technical architecture of your past work.
• Conflict Resolution – Navigating differences in opinion with product managers or engineering peers.
• Adaptability – Handling changing requirements or tight deadlines in a fast-paced environment.

Example questions or scenarios:

• "Tell me about a time you had to make a technical compromise to meet a business deadline."
• "Describe a situation where you had to take ownership of a project outside your comfort zone."