As a Software Engineer at LendingTree, you play a pivotal role in shaping the technology that powers a leading online marketplace for consumers to compare financial products. This position is critical not only for developing innovative software solutions but also for ensuring that users have a seamless experience when navigating the platform. Your work directly impacts the efficiency and effectiveness of products that help consumers make informed financial decisions, contributing to LendingTree’s mission of empowering consumers in their financial journeys. In this role, you will collaborate with cross-functional teams including product managers, designers, and other engineers to tackle complex challenges. You will be working on products that range from loan comparisons to mortgage calculators, all the while maintaining a user-centric approach. The scale and complexity of the systems you will work with provide an exciting opportunity to innovate and make significant contributions to the financial technology landscape. Expect to engage with current technologies and methodologies that support robust, scalable, and high-performance applications. You will be part of an environment that values creativity and problem-solving, allowing you to push boundaries and explore new ideas that enhance user experience.
Phone Screening
reportedInitial phone screening to assess candidate's fit for the role.
What to demonstrate
- Initial phone screening to assess candidate's fit for the role
- Depth in Object-Oriented Programming (OOP)
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.
Technical Interviews
reportedMultiple rounds of technical assessments including coding challenges.
What to demonstrate
- Multiple rounds of technical assessments including coding challenges
- Depth in Object-Oriented Programming (OOP)
How to prepare
- Answer aloud and timed: What are the benefits and drawbacks of using a relational database versus a NoSQL database?
- Answer aloud and timed: Describe how you would optimize a slow-running query.
Behavioral Interviews
reportedInterviews focusing on past projects and cultural fit within the company.
What to demonstrate
- Interviews focusing on past projects and cultural fit within the company
- Depth in Object-Oriented Programming (OOP)
How to prepare
- Prepare three examples from your own work, each with a decision you made and an outcome you can quantify.
- Re-read the description of the behavioral interviews above and write down what you would ask to confirm before it.
Team Member Interviews
reportedDiscussions with potential team members to evaluate collaboration skills.
What to demonstrate
- Discussions with potential team members to evaluate collaboration skills
- Depth in Object-Oriented Programming (OOP)
How to prepare
- Answer aloud and timed: Given a list of integers, find the two numbers that sum to a specific target.
- Answer aloud and timed: Explain how you would implement a sorting algorithm, such as quicksort or mergesort.
PracHub editorial advice for the preparation topics above.
Understand the Products
Familiarize yourself with LendingTree's suite of products and how they serve consumers. This knowledge will help you contextualize your technical skills during discussions.
Practice Behavioral Questions
Prepare for behavioral questions by reflecting on your past experiences and how they relate to the role. Use the STAR method (Situation, Task, Action, Result) to structure your responses.
Emphasize Teamwork
Highlight your ability to work collaboratively with others, as the company values teamwork and collective problem-solving.
Follow Up
Don't hesitate to send a follow-up email after interviews to express gratitude and reiterate your interest in the position. This shows professionalism and enthusiasm.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
How would you implement a binary search tree?
How would you implement a binary search tree?
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 determine if a string has all unique characters.
Write a function to determine if a string has all unique characters.
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 a list of integers, find the two numbers that sum to a specific target.
Given a list of integers, find the two numbers that sum 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?
Explain how you would implement a sorting algorithm, such as quicksort or mergesort.
Explain how you would implement a sorting algorithm, such as quicksort or mergesort.
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?
Create a function for validating a binary search tree.
Create a function for validating a binary search tree.
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?
How would you approach solving a dynamic programming problem?
How would you approach solving a dynamic programming problem?
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?
Describe how you would optimize a slow-running query.
Describe how you would optimize a slow-running query.
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?
Find version gaps and relay lag with window functions
outbox_event holds event_id, aggregate_type, aggregate_id, aggregate_version, event_type, payload, status ('pending','published','dead'), attempts, created_at, published_at. A projection is missing rows and you must decide whether the relay skipped events or the consumer dropped them. Write three queries over the last seven days: one listing every aggregate_id whose published aggregate_version sequence has a hole, one giving per-day counts with a running total, and one returning the newest published event per aggregate. For each, say where the window function is evaluated relative to WHERE and LIMIT. PostgreSQL 16.
Approach
- Gaps: compute lead(aggregate_version) OVER (PARTITION BY aggregate_id ORDER BY aggregate_version) in a subquery, then filter next_version <> aggregate_version + 1 in the outer query. Window functions are evaluated after WHERE, GROUP BY and HAVING and before the outer ORDER BY and LIMIT, so the predicate cannot sit in the same WHERE clause and PostgreSQL 16 has no QUALIFY.
- Say what the seven-day filter does to the answer: it truncates every partition, so the first row per aggregate has no predecessor inside the window and a hole spanning the boundary is invisible. Widen the window, or join to resource.version as the authority for the true maximum.
- Running total: SELECT date_trunc('day', created_at) AS d, count() AS n, sum(count()) OVER (ORDER BY date_trunc('day', created_at) ROWS UNBOUNDED PRECEDING). An aggregate inside a window call is legal because grouping runs before windowing. The grouping key is unique per row here so ROWS and RANGE agree, but write the frame anyway — over ungrouped rows with tied timestamps the default RANGE frame pulls in every peer row and the total jumps.
- Newest per aggregate: DISTINCT ON (aggregate_id) ... ORDER BY aggregate_id, aggregate_version DESC is the cheap PostgreSQL-only form when an index matches that order; row_number() OVER (PARTITION BY aggregate_id ORDER BY aggregate_version DESC) = 1 is the portable form and needs a subquery for the same evaluation-order reason as the gap query.
Follow-up
- Relay failover redelivers events. Does a duplicate break the gap query, and how would you detect one from this table alone?
- Turn the gap check into a continuous monitor rather than a query someone runs after an incident. What does it watch?
Explain the difference between an abstract class and an interface.
Explain the difference between an abstract class and an interface.
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- Work from the requirement backwards to the design.
Follow-up
- What assumption would you test first?
- How would you know your answer was wrong?
What are the benefits and drawbacks of using a relational database versus a NoSQL database?
What are the benefits and drawbacks of using a relational database versus a NoSQL database?
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- Work from the requirement backwards to the design.
Follow-up
- What assumption would you test first?
- How would you know your answer was wrong?
What is the importance of RESTful APIs in modern web applications?
What is the importance of RESTful APIs in modern web applications?
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- Work from the requirement backwards to the design.
Follow-up
- What assumption would you test first?
- How would you know your answer was wrong?
Design a URL shortening service. What components would you include?
Design a URL shortening service. What components would you include?
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?
How would you architect a microservices-based application?
How would you architect a microservices-based application?
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 ensure scalability and reliability in an application.
Explain how you would ensure scalability and reliability in an application.
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?
What considerations would you have for database design in a web application?
What considerations would you have for database design in a web application?
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?
Discuss how you would handle data consistency in a distributed system.
Discuss how you would handle data consistency in a distributed system.
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?
Every query on one table stalls for forty seconds mid-deploy
During a release on PostgreSQL, every query touching resource times out for about 40 seconds and then recovers with no intervention. The release ran one migration, ALTER TABLE resource ADD COLUMN archived_reason TEXT, and the migration log shows it completing in 6 ms. Unrelated tables showed no change in error rate. Explain how a 6 ms statement caused a 40-second stall, give the ordered checks you would run on a live system to confirm it, and give the migration procedure that prevents a repeat.
Approach
- Separate the statement's duration from the lock's duration. ADD COLUMN with no default is a catalogue-only change and genuinely runs in milliseconds, but it requires ACCESS EXCLUSIVE, and it cannot acquire that until every transaction already touching the table has finished.
- Account for the queueing, which is the part that surprises people. A lock request that is waiting blocks later requests for conflicting modes behind it rather than letting them overtake, so one long-open transaction holds the DDL and the DDL holds all the traffic. The stall length is set by the longest open transaction, not by the size of the change.
- Confirm on a live system in this order: pg_stat_activity for that table ordered by xact_start, looking for the oldest transaction and specifically for state = idle in transaction; then pg_locks where granted = false to find the waiter; then join them on pid to name blocker and blocked. pg_blocking_pids() does that join for you and is the fastest single call.
- Prevent rather than merely time it better. Set lock_timeout to a second or two on the migration session so the DDL abandons the queue after a bounded wait and is retried, instead of holding it for as long as the oldest transaction lives. Be exact about what that buys: queries arriving during the wait still queue behind the pending ACCESS EXCLUSIVE request, so each attempt costs them up to one lock_timeout of added latency. The outage goes from 40 seconds to about one second per attempt, not to zero. Also run migrations away from deploy-time peaks, and put a statement timeout and an idle-in-transaction timeout on the analytics role that opens the long transactions.
Follow-up
- The same release also wants NOT NULL on that column. What is the sequence that gets there without a long lock?
- Your lock_timeout retry fails ten times in a row because the analytics transaction is always open. What do you change?
Built from the rounds and topics LendingTree candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the LendingTree loop
- Write out the reported sequence: Phone Screening, Technical Interviews, Behavioral Interviews, Team Member Interviews.
- 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 Object-Oriented Programming (OOP)
- Spend the session on Object-Oriented Programming (OOP), which LendingTree candidates report being tested on.
- Write one worked example in Object-Oriented Programming (OOP) and time yourself on it.
Deliverable: One timed worked example in Object-Oriented Programming (OOP).
03Work Algorithms
- Spend the session on Algorithms, which LendingTree candidates report being tested on.
- Write one worked example in Algorithms and time yourself on it.
Deliverable: One timed worked example in Algorithms.
04Work Data Structures
- Spend the session on Data Structures, which LendingTree candidates report being tested on.
- Write one worked example in Data Structures and time yourself on it.
Deliverable: One timed worked example in Data Structures.
05Answer out loud: Technical / Domain Questions
- Answer aloud, timed: Explain the difference between an abstract class and an interface.
- Answer aloud, timed: How would you implement a binary search tree?
Deliverable: Spoken answers to 2 reported Technical / Domain Questions question(s), under time.
06Answer out loud: Coding / Algorithms
- Answer aloud, timed: Write a function to determine if a string has all unique characters.
- Answer aloud, timed: Given a list of integers, find the two numbers that sum to a specific target.
Deliverable: Spoken answers to 2 reported Coding / Algorithms question(s), under time.
07Answer out loud: Behavioral / Leadership
- Answer aloud, timed: Describe a situation where you had to work collaboratively with a team.
- Answer aloud, timed: How do you handle tight deadlines and pressure?
Deliverable: Spoken answers to 2 reported Behavioral / Leadership 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.
Describe a situation where you had to work collaboratively with a team.
Describe a situation where you had to work collaboratively with a team.
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?
How do you handle tight deadlines and pressure?
How do you handle tight deadlines and pressure?
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?
What motivates you to succeed in your role?
What motivates you to succeed in your role?
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?
Tell us about a time you received constructive feedback and how you handled it.
Tell us about a time you received constructive feedback and how you handled 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?
How would you approach a conflict with a team member?
How would you approach a conflict with a team member?
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
Describe a situation where you had to work collaboratively with a team.
- 02
How do you handle tight deadlines and pressure?
- 03
What motivates you to succeed in your role?
- 04
Tell us about a time you received constructive feedback and how you handled it.
How difficult is the interview process?
The interview process is generally considered challenging, with a mix of technical and behavioral questions that assess both your skills and fit within the company culture. Candidates typically prepare for several weeks to ensure they can demonstrate their abilities effectively.
LendingTree Software Engineer candidate reports ↗What differentiates successful candidates?
Successful candidates often showcase a solid understanding of technical concepts, strong problem-solving skills, and the ability to communicate effectively. Demonstrating passion for the role and alignment with company values also sets candidates apart.
LendingTree Software Engineer candidate reports ↗What is the culture like at LendingTree?
The culture at LendingTree is collaborative and innovative, emphasizing teamwork and user-centric development. Employees are encouraged to share ideas and contribute to ongoing projects, fostering an environment of continuous learning.
LendingTree Software Engineer candidate reports ↗What is the typical timeline from initial screen to offer?
The timeline can vary but generally takes between 4-6 weeks. Candidates may go through multiple rounds of interviews, including technical assessments and behavioral interviews.
LendingTree Software Engineer candidate reports ↗Are there remote work opportunities?
While many positions are based in Charlotte, NC, LendingTree has embraced flexible work arrangements, including remote and hybrid options. Check the specific job posting for details on work location flexibility.
LendingTree Software Engineer candidate reports ↗How should I prepare for the coding assessments?
To prepare effectively, practice coding problems on platforms like LeetCode or HackerRank. Focus on data structures and algorithms, and be prepared to explain your thought process as you solve problems.
LendingTree Software Engineer candidate reports ↗What topics does LendingTree test in interviews?
LendingTree interviews most often cover SQL, Snowflake, Marketing Analytics, Technical Communication, and Experimentation / A/B Testing. The exact emphasis depends on the specific role you apply for.
LendingTree 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.
- 01LendingTree 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
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