As a Software Engineer at Avathon, you play a pivotal role in developing innovative solutions that impact our products and users directly. This position is vital to our mission of delivering cutting-edge technology that enhances user experiences and drives business growth. You will work closely with cross-functional teams to design, implement, and optimize software systems that are scalable, reliable, and user-friendly. The complexity of the projects you will engage with at Avathon is significant, involving large-scale systems and intricate architectures. You will have the opportunity to contribute to various domains, including cloud computing, data processing, and user interface development. This role not only requires technical expertise but also strategic thinking, as your work will influence the future direction of our products and the satisfaction of our users. Expect to be challenged while making meaningful contributions to exciting projects that define the forefront of technology.
Phone Screening
reportedInitial screening call to assess candidate's background and fit for the role.
What to demonstrate
- Initial screening call to assess candidate's background and fit for the role
- Depth in System Design
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 Assessments
reportedIncludes coding challenges and system design discussions to evaluate technical skills.
What to demonstrate
- Includes coding challenges and system design discussions to evaluate technical skills
- Depth in System Design
How to prepare
- Answer aloud and timed: What are the principles of object-oriented programming?
- Answer aloud and timed: Write a function to find the nearest common ancestor of two nodes in a binary tree.
Multiple Interview Rounds
reportedCandidates participate in several interviews focusing on various skill aspects.
What to demonstrate
- Candidates participate in several interviews focusing on various skill aspects
- Depth in System Design
How to prepare
- Answer aloud and timed: Solve a problem to reverse a linked list in place.
- Answer aloud and timed: Given an array of integers, find two numbers such that they add up to a specific target.
PracHub editorial advice for the preparation topics above.
Practice whiteboarding
Many interviews will require you to solve problems on a whiteboard. Familiarize yourself with this format to reduce anxiety during the actual interview.
Communicate your thought process
Speak aloud as you work through problems to give interviewers insight into your reasoning and approach.
Research the company
Understanding Avathon's products, culture, and recent developments will allow you to tailor your responses and demonstrate your interest.
Prepare for behavioral questions
Think of specific examples from your past experiences that illustrate your skills and values.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
How do you manage memory in a programming language of your choice?
How do you manage memory in a programming language of your choice?
Approach
- Say what the runtime actually does before reasoning about the code.
- Name what is shared across threads and what owns each piece of state.
- Identify the window where an invariant is briefly untrue.
- Distinguish a value from a reference to it, and say which one you handed out.
Follow-up
- What happens if two callers reach this at the same time?
- Where could this allocate more than you expect?
Solve a problem to reverse a linked list in place.
Solve a problem to reverse a linked list in place.
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, find two numbers such that they add up to a specific target.
Given an array of integers, find two numbers such that they 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?
Discuss the trade-offs between SQL and NoSQL databases in a specific use case.
Discuss the trade-offs between SQL and NoSQL databases in a specific use case.
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?
Denormalise tenant onto revisions and backfill it live
resource_revision (revision_id, resource_id, version, actor_user_id, change_kind, patch, request_id, created_at) has 400M rows and no tenant column; tenant_id lives only on resource. Two reads need it: a tenant-scoped audit feed ordered by created_at DESC, and an offboarding purge. Both join back to resource today. Justify adding tenant_id to resource_revision against those two reads, name the anomaly the copy introduces and the constraint that prevents it, then give the ordered migration for a live table taking 1.2k writes/second — the lock each step takes, how the backfill is batched, and where each step stops being reversible. PostgreSQL 16.
Approach
- Justify from the access path rather than from taste. Without the column, the audit feed either scans resource_revision by created_at and discards other tenants' rows, or resolves the tenant's resource_ids first and probes with them — both proportional to the tenant's whole history rather than to one page. With (tenant_id, created_at DESC, revision_id DESC) it is a seek that stops at 50 rows, and the purge becomes a ranged delete instead of a join.
- Name the cost exactly: a second copy of a fact can disagree with the first. Make the disagreement unwritable rather than documented — add UNIQUE (resource_id, tenant_id) on resource so it can serve as a foreign-key target, then FOREIGN KEY (resource_id, tenant_id) REFERENCES resource (resource_id, tenant_id) on the revision table. A revision can then only ever carry its parent's tenant.
- Step one, expand: ALTER TABLE resource_revision ADD COLUMN tenant_id BIGINT NULL, with no default, so it is a catalogue change and no rewrite. It still needs ACCESS EXCLUSIVE for an instant, and that instant queues behind the longest open transaction on the table while every later query queues behind it — set lock_timeout to 2s and retry rather than wait.
- Step two, dual-write: deploy the writer that populates tenant_id on every new revision while reads still use the join. Reversible by redeploying the previous build, because nothing reads the column yet.
Follow-up
- The backfill is half finished and a rollback is required. What state is the table in, and what does the previous build do with a half-populated column?
- How do you verify the backfill actually finished, given rows are still being inserted while it runs?
Explain the difference between a stack and a queue. Provide examples.
Explain the difference between a stack and a queue. Provide examples.
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 principles of object-oriented programming?
What are the principles of object-oriented programming?
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?
Write a function to find the nearest common ancestor of two nodes in a binary tree.
Write a function to find the nearest common ancestor of two nodes in a binary tree.
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?
Design a URL shortening service like bit.ly. What considerations would you make?
Design a URL shortening service like bit.ly. What considerations would you make?
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 architect a real-time messaging application.
Explain how you would architect a real-time messaging 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?
Describe your thought process in deciding which technology stack to use for a new application.
Describe your thought process in deciding which technology stack to use for a new application.
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?
Discuss a project where you had to balance technical debt with feature delivery.
Discuss a project where you had to balance technical debt with feature delivery.
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?
How would you approach debugging a critical system failure?
How would you approach debugging a critical system failure?
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 Avathon candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the Avathon loop
- Write out the reported sequence: Phone Screening, Technical Assessments, Multiple Interview Rounds.
- 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 3 reported rounds, with the weakest marked.
02Work System Design
- Spend the session on System Design, which Avathon 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.
03Work Data Structures
- Spend the session on Data Structures, which Avathon 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.
04Work Algorithms
- Spend the session on Algorithms, which Avathon candidates report being tested on.
- Write one worked example in Algorithms and time yourself on it.
Deliverable: One timed worked example in Algorithms.
05Answer out loud: Technical / Domain Questions
- Answer aloud, timed: Explain the difference between a stack and a queue. Provide examples.
- Answer aloud, timed: How do you manage memory in a programming language of your choice?
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 find the nearest common ancestor of two nodes in a binary tree.
- Answer aloud, timed: Solve a problem to reverse a linked list in place.
Deliverable: Spoken answers to 2 reported Coding / Algorithms question(s), under time.
07Answer out loud: System Design / Architecture
- Answer aloud, timed: Design a URL shortening service like bit.ly. What considerations would you make?
- Answer aloud, timed: Explain how you would architect a real-time messaging application.
Deliverable: Spoken answers to 2 reported System Design / Architecture 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 time when you faced a significant challenge in a project. How did you handle it?
Describe a time when you faced a significant challenge in a project. How did you handle 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 do you prioritize tasks when working on multiple projects?
How do you prioritize tasks when working on multiple projects?
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?
Explain a situation where you had to work with a difficult team member and how you managed it.
Explain a situation where you had to work with a difficult team member and how you managed 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?
- 01
Describe a time when you faced a significant challenge in a project. How did you handle it?
- 02
How do you prioritize tasks when working on multiple projects?
- 03
Explain a situation where you had to work with a difficult team member and how you managed it.
How difficult are the interviews, and how much preparation time is typical?
Interviews at Avathon can be challenging, requiring a solid understanding of technical concepts and problem-solving skills. Candidates typically spend several weeks preparing, focusing on coding challenges and system design.
Avathon Software Engineer candidate reports ↗What differentiates successful candidates?
Successful candidates demonstrate strong technical proficiency, effective communication skills, and a collaborative mindset. They show a genuine interest in the company's mission and values.
Avathon Software Engineer candidate reports ↗What is the culture like at Avathon?
Avathon fosters a culture of innovation, collaboration, and continuous learning. Team members are encouraged to share ideas and work together to overcome challenges.
Avathon Software Engineer candidate reports ↗What is the typical timeline from the initial screen to offer?
The hiring process can take several weeks, depending on the number of candidates and interviews. Generally, candidates can expect to receive feedback within days of each interview stage.
Avathon Software Engineer candidate reports ↗Are there remote work options or hybrid expectations?
Avathon supports flexible working arrangements. Depending on the role, you may have the option to work remotely or follow a hybrid model.
Avathon Software Engineer candidate reports ↗What topics does Avathon test in interviews?
Avathon interviews most often cover Python, Technical Communication, Machine Learning, Algorithms, and Data Structures. The exact emphasis depends on the specific role you apply for.
Avathon 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.
- 01Avathon 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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