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.
Recruiter Screen
reportedInitial conversation to discuss your background and align expectations.
What to demonstrate
- Initial conversation to discuss your background and align expectations
- Depth in Python
How to prepare
- Be able to walk your CV end to end in two minutes, and say why this company specifically.
- Have your salary expectations, notice period and location constraints ready, and ask for the rest of the loop in writing.
Hiring Manager Interview
reportedDiscussion with the hiring manager to explore your technical experience in depth.
What to demonstrate
- Discussion with the hiring manager to explore your technical experience in depth
- Depth in Python
How to prepare
- Prepare two projects you led end to end, each with the decision you owned and what it cost.
- Have three questions about the team's roadmap and how success is measured in the first six months.
Take-Home Assessment
reportedA practical coding challenge in Python to demonstrate your hands-on skills.
What to demonstrate
- A practical coding challenge in Python to demonstrate your hands-on skills
- Depth in Python
How to prepare
- Answer aloud and timed: Write a query to find the second-highest booking value from a table of transaction records.
- Answer aloud and timed: How would you join a travel search intent table with a conversions table to calculate the conversion rate per destination?
Multi-Round Panel Interview
reportedStructured panel interview covering SQL, Python live coding, System Design, and Behavioral evaluations.
What to demonstrate
- Structured panel interview covering SQL, Python live coding, System Design, and Behavioral evaluations
- Depth in Python
How to prepare
- Answer aloud and timed: Write a query utilizing aggregate functions and
GROUP BYto find the top five travel destinations by search volume in the last 30 days. - Answer aloud and timed: Explain the difference between an
INNER JOIN,LEFT JOIN, andOUTER JOIN, and provide a scenario where aLEFT JOINis necessary for reporting.
PracHub editorial advice for the preparation topics above.
Structure your resume stories
Interviewers place a high value on your past experience. Prepare 3-4 detailed stories about your previous projects, emphasizing the technical trade-offs you made, the scale of the data you handled, and the business impact of your work.
Watch the clock during the panel
The onsite rounds are tightly scheduled at 45 minutes each. Keep your answers focused and monitor the time, especially during the coding and SQL rounds, to ensure you complete the core requirements of each question.
Show interest in the travel industry
Demonstrating an understanding of travel search patterns, booking funnels, or ad tech concepts can significantly set you apart from other candidates during conversations with hiring managers and directors.
Communicate your thought process
Whether you are writing Python code or designing a database schema, talk through your reasoning. Interviewers are interested in how you arrive at a solution and how you handle feedback or hints when you get stuck.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
How do you find a missing number between two arrays where one contains $n$ unique elements and the other conta
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?
Approach
- Restate the input: its shape, its size, and what is guaranteed about it.
- Name the brute-force solution and its complexity before improving on it.
- Choose the data structure from the access pattern, not from familiarity.
- State the target complexity and say which constraint rules the naive version out.
Follow-up
- How does this change if the input no longer fits in memory?
- What is the worst case, and how likely is it on real data?
Write a function to reverse a string or check if a string is a palindrome, optimizing for space complexity.
Write a function to reverse a string or check if a string is a palindrome, optimizing for space complexity.
Approach
- Restate the input: its shape, its size, and what is guaranteed about it.
- Name the brute-force solution and its complexity before improving on it.
- Choose the data structure from the access pattern, not from familiarity.
- State the target complexity and say which constraint rules the naive version out.
Follow-up
- How does this change if the input no longer fits in memory?
- What is the worst case, and how likely is it on real data?
Given an array of integers, return the indices of the two numbers that add up to a specific target.
Given an array of integers, return the indices of the two numbers that add up to a specific target.
Approach
- Restate the input: its shape, its size, and what is guaranteed about it.
- Name the brute-force solution and its complexity before improving on it.
- Choose the data structure from the access pattern, not from familiarity.
- State the target complexity and say which constraint rules the naive version out.
Follow-up
- How does this change if the input no longer fits in memory?
- What is the worst case, and how likely is it on real data?
Write a query to find the second-highest booking value from a table of transaction records.
Write a query to find the second-highest booking value from a table of transaction records.
Approach
- Name the grain you start from and join outward from it.
- Check whether any join is one-to-many before aggregating, or the sums inflate.
- Say which index the query would use, and what makes it unusable.
- Handle the rows that do not match: that is usually the actual question.
Follow-up
- How does the query change if that join becomes one-to-many?
- What happens to this when the table is ten times larger?
How would you join a travel search intent table with a conversions table to calculate the conversion rate per
How would you join a travel search intent table with a conversions table to calculate the conversion rate per destination?
Approach
- Name the grain you start from and join outward from it.
- Check whether any join is one-to-many before aggregating, or the sums inflate.
- Say which index the query would use, and what makes it unusable.
- Handle the rows that do not match: that is usually the actual question.
Follow-up
- How does the query change if that join becomes one-to-many?
- What happens to this when the table is ten times larger?
Write a query utilizing aggregate functions and `GROUP BY` to find the top five travel destinations by search
Write a query utilizing aggregate functions and GROUP BY to find the top five travel destinations by search volume in the last 30 days.
Approach
- Name the grain you start from and join outward from it.
- Check whether any join is one-to-many before aggregating, or the sums inflate.
- Say which index the query would use, and what makes it unusable.
- Handle the rows that do not match: that is usually the actual question.
Follow-up
- How does the query change if that join becomes one-to-many?
- What happens to this when the table is ten times larger?
Explain the difference between an `INNER JOIN`, `LEFT JOIN`, and `OUTER JOIN`, and provide a scenario where a
Explain the difference between an INNER JOIN, LEFT JOIN, and OUTER JOIN, and provide a scenario where a LEFT JOIN is necessary for reporting.
Approach
- Name the grain you start from and join outward from it.
- Check whether any join is one-to-many before aggregating, or the sums inflate.
- Say which index the query would use, and what makes it unusable.
- Handle the rows that do not match: that is usually the actual question.
Follow-up
- How does the query change if that join becomes one-to-many?
- What happens to this when the table is ten times larger?
Implement a basic rate limiter or helper function to parse and clean incoming travel search query strings.
Implement a basic rate limiter or helper function to parse and clean incoming travel search query strings.
Approach
- Say who the caller is and what they do when the call fails halfway.
- Define the identity of a request so a retry cannot double-apply it.
- Separate accepted, pending, failed and confirmed; they are different facts.
- Design the error taxonomy before the success shape; callers branch on it.
Follow-up
- What happens if the caller retries after a timeout?
- How does a client discover it is on an old version of this contract?
How would you design a schema to store and query high-volume travel search data?
How would you design a schema to store and query high-volume travel search data?
Approach
- Fix the scope first: who calls this, how often, and what they do when it fails.
- Name the read and write paths separately; they rarely have the same bottleneck.
- Choose a partition key and say what query it makes expensive.
- State the consistency you need, and where you are willing to be stale.
Follow-up
- What breaks first when traffic grows ten times?
- How does this behave when that dependency is down for an hour?
Design a real-time tracking system that counts the number of ad impressions served per campaign.
Design a real-time tracking system that counts the number of ad impressions served per campaign.
Approach
- Fix the scope first: who calls this, how often, and what they do when it fails.
- Name the read and write paths separately; they rarely have the same bottleneck.
- Choose a partition key and say what query it makes expensive.
- State the consistency you need, and where you are willing to be stale.
Follow-up
- What breaks first when traffic grows ten times?
- How does this behave when that dependency is down for an hour?
Explain how you would design a backend API to support a travel booking dashboard used by external clients.
Explain how you would design a backend API to support a travel booking dashboard used by external clients.
Approach
- Fix the scope first: who calls this, how often, and what they do when it fails.
- Name the read and write paths separately; they rarely have the same bottleneck.
- Choose a partition key and say what query it makes expensive.
- State the consistency you need, and where you are willing to be stale.
Follow-up
- What breaks first when traffic grows ten times?
- How does this behave when that dependency is down for an hour?
Describe a situation where you had to debug a critical production issue under tight time pressure.
Describe a situation where you had to debug a critical production issue under tight time pressure.
Approach
- Establish what changed and when, before forming any theory.
- Pick a bisection that eliminates candidates whichever way it turns out.
- Check the instrumentation before believing the symptom.
- Separate the trigger from the cause; the deploy is rarely the bug.
Follow-up
- What would you look at first, and what would it rule out?
- How would you tell a cause from a coincidence here?
Built from the rounds and topics Sojern candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the Sojern loop
- Write out the reported sequence: Recruiter Screen, Hiring Manager Interview, Take-Home Assessment, Multi-Round Panel Interview.
- For each round, write one sentence on what it is judging, from the description above, and mark the one you are least ready for.
Deliverable: A one-page map of the 4 reported rounds, with the weakest marked.
02Work Python
- Spend the session on Python, which Sojern candidates report being tested on.
- Write one worked example in Python and time yourself on it.
Deliverable: One timed worked example in Python.
03Work SQL
- Spend the session on SQL, which Sojern candidates report being tested on.
- Write one worked example in SQL and time yourself on it.
Deliverable: One timed worked example in SQL.
04Work System Design
- Spend the session on System Design, which Sojern candidates report being tested on.
- Write one worked example in System Design and time yourself on it.
Deliverable: One timed worked example in System Design.
05Answer out loud: Coding & Algorithms
- Answer aloud, timed: 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?
- Answer aloud, timed: Write a function to reverse a string or check if a string is a palindrome, optimizing for space complexity.
Deliverable: Spoken answers to 2 reported Coding & Algorithms question(s), under time.
06Answer out loud: SQL & Data Manipulation
- Answer aloud, timed: Write a query to find the second-highest booking value from a table of transaction records.
- Answer aloud, timed: How would you join a travel search intent table with a conversions table to calculate the conversion rate per destination?
Deliverable: Spoken answers to 2 reported SQL & Data Manipulation question(s), under time.
07Answer out loud: System & Data Design
- Answer aloud, timed: How would you design a schema to store and query high-volume travel search data?
- Answer aloud, timed: Design a real-time tracking system that counts the number of ad impressions served per campaign.
Deliverable: Spoken answers to 2 reported System & Data Design question(s), under time.
Expand any day for tasks and deliverables. Your progress is saved on this device.
Behavioural rounds judge the decision you made and what it cost.
How do you handle data consistency and latency when syncing search data across multiple geographical regions?
How do you handle data consistency and latency when syncing search data across multiple geographical regions?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- Name the disagreement and how you resolved it with evidence.
Follow-up
- What would you do differently if you ran that again?
- How did you know your change caused the improvement?
Walk me through a challenging technical project on your resume, explaining the trade-offs you made during the
Walk me through a challenging technical project on your resume, explaining the trade-offs you made during the design phase.
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- Name the disagreement and how you resolved it with evidence.
Follow-up
- What would you do differently if you ran that again?
- How did you know your change caused the improvement?
Describe a time when you had a disagreement with a team member or product manager. How did you resolve it?
Describe a time when you had a disagreement with a team member or product manager. How did you resolve it?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- Name the disagreement and how you resolved it with evidence.
Follow-up
- What would you do differently if you ran that again?
- How did you know your change caused the improvement?
Why do you want to work at Sojern, and what interests you about the travel technology industry?
Why do you want to work at Sojern, and what interests you about the travel technology industry?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- Name the disagreement and how you resolved it with evidence.
Follow-up
- What would you do differently if you ran that again?
- How did you know your change caused the improvement?
- 01
How do you handle data consistency and latency when syncing search data across multiple geographical regions?
- 02
Walk me through a challenging technical project on your resume, explaining the trade-offs you made during the design phase.
- 03
Describe a time when you had a disagreement with a team member or product manager. How did you resolve it?
- 04
Why do you want to work at Sojern, and what interests you about the travel technology industry?
How difficult is the technical interview at Sojern?
The technical questions are generally rated as average in difficulty, focusing on LeetCode easy-to-medium coding challenges and practical SQL queries. The difficulty lies in the breadth of the process, which covers multiple distinct technical disciplines like live coding, take-home exercises, database querying, and system design.
Sojern Software Engineer candidate reports ↗What is the typical timeline from the first screen to an offer?
The entire process can take anywhere from three to six weeks. Because Sojern utilizes a structured hiring process to evaluate multiple candidates, the time between rounds and the final decision-making phase can sometimes be longer than at other startups.
Sojern Software Engineer candidate reports ↗How important is the SQL round compared to the Python coding round?
Both are highly critical. Sojern is a data-driven platform, meaning that your ability to manipulate and query large datasets efficiently is just as important as your general software engineering and algorithmic capabilities.
Sojern Software Engineer candidate reports ↗Does Sojern support remote work for Software Engineers?
Sojern offers hybrid and remote work options depending on the specific team, role, and office location (such as San Francisco, Dublin, or Omaha). Be sure to clarify the exact location and hybrid expectations with your recruiter during the initial call. ##### Tip During the behavioral rounds, Sojern interviewers highly value structured storytelling. Use the STAR method (Situation, Task, Action, Result) to keep your answers concise and impactful.
Sojern Software Engineer candidate reports ↗What topics does Sojern test in interviews?
Sojern interviews most often cover Stakeholder Management, Python, SQL, Behavioral Interviewing, and Requirements Gathering. The exact emphasis depends on the specific role you apply for.
Sojern Software Engineer candidate reports ↗Sources & methodology 3 sources ↗
No official company page is cited. Rounds and questions come from candidate reports and PracHub editorial material; each source shows the date it was read.
- 01Sojern Software Engineer candidate reports ↗
Company-reported rounds, questions and FAQ.
Candidate reports · Accessed 2026-09-22 - 02PracHub Software Engineer practice ↗
PracHub practice material, not company-reported.
PracHub page · Accessed 2026-09-22 - 03PracHub preparation framework ↗
PracHub preparation guidance.
PracHub page · Accessed 2026-09-22
Explore related engineering environments and compare the preparation focus.
Discord Software Engineer Interview Guide
Database practice for Discord candidates: how an index changes a query plan, and which anomalies survive a given isolation level, since read committed still permits non-repeatable reads.
CoreWeave Software Engineer Interview Guide
Failure-handling practice for CoreWeave software engineer candidates: requests whose outcome a timeout leaves unknown, where a retry is safe, and deduplicating at the receiver instead of assuming exactly-once delivery.
Rystad Energy Software Engineer Interview Guide
Prepare for Rystad Energy software interviews with worked Python validation, OOP and decorator examples, plus an ingestion case and practical checks.
Western Digital Software Engineer Interview Guide
What Western Digital asks Software Engineer candidates, from reported rounds and questions.