Type · algorithmic

How to Pass the October Software Engineer Interview in 2026
The October Software Engineer interview runs 5 rounds: Recruiter Screen, Coding Screen, System Design, Onsite Coding, and Behavioral / Leadership. JobMentis holds 12 Software Engineer questions for October, last updated October 23, 2026.
Growth · Software Engineer Interview Guide
Sign up to see ATSHeadquartered in FranceInterview language: English
The October DNA (TL;DR)
The October Interview Loop
Your onsite loop will typically consist of 5 rounds.
- 1
Round 1
Recruiter ScreenMotivation, role fit, logistics. - 2
Round 2
Coding ScreenLeetCode-medium algorithmic problems under time pressure. - 3
Round 3
System DesignDistributed systems, trade-offs at scale, architecture under constraints. - 4
Round 4
Onsite CodingLeetCode-hard problems, reasoning about defects, code clarity, edge cases. - 5
Round 5
Behavioral / LeadershipPast evidence of ownership, influence, resolving conflict.
The Danger Zone: Top Reasons Candidates Fail
Based on our database of October interview outcomes, avoid these common traps:
- Providing a resolution that ignored the long-term maintainability of the codebase
- Using incorrect formulas for monthly payment calculation (e.g., APR vs. monthly rate).
- Overlooking the real-time requirement and proposing batch processing.
- Failing to mention the specific financial data consistency constraints involved
Test Yourself: October Interview Questions
Three questions from the October bank.
Type · past-experience
STARType · coding
+ many more questions, signals, and worked examples
Sign up to unlock the full October grading rubric
October Interview Question Bank
A sample from our database, grouped by round. Sign up to see the full set.
9 of 12 questions shown
Recruiter Screen
1- 1
Type · motivation
Why are you interested in joining October, a fintech company focused on SME lending, compared to other opportunities in the tech industry?
Coding Screen
2- 2
Type · algorithmic
Given a list of loan applications, each with an amount, interest rate, and a submission timestamp, write a function to calculate the total approved loan amount for a given day, considering that applications are approved sequentially and a loan is only approved if its amount is less than or equal to the remaining available capital for that day. Assume a fixed daily capital pool. - 3
Type · algorithmic
Implement a function that takes a list of transactions (each with a user ID, amount, and timestamp) and returns the top K users with the highest net transaction volume within a specified time window. Handle potential ties.
System Design
3- 4
Type · design
CIRCLESDesign a system to automatically detect and flag potentially fraudulent loan applications in real-time. Consider data sources, processing pipeline, fraud detection models, and alerting mechanisms. - 5
Type · design
CIRCLESDesign a microservice responsible for calculating credit scores for loan applicants. Consider the data inputs, the scoring algorithm's complexity, potential external dependencies (e.g., credit bureaus), and how to ensure low latency and high availability. - + 1 more questions in this round (sign up to unlock)
Onsite Coding
3- 6
Type · algorithmic
Implement a rate limiter for API requests to prevent abuse. The rate limiter should allow a maximum of N requests per user within a M-minute window. Consider different strategies (e.g., token bucket, leaky bucket) and discuss their trade-offs. - 7
Type · coding
Write a function to simulate loan amortization. Given a principal amount, annual interest rate, and loan term (in years), calculate and return the monthly payment and generate an amortization schedule showing the principal and interest paid each month, and the remaining balance. - + 1 more questions in this round (sign up to unlock)
Behavioral / Leadership
3- 8
Type · past-experience
STARTell me about a time you had to make a significant technical decision with incomplete information or under pressure. How did you approach it, and what was the outcome? - 9
Type · past-experience
STARDescribe a complex bug you encountered in a production system. Walk me through your process of diagnosing and fixing it, and what steps you took to prevent similar issues in the future. - + 1 more questions in this round (sign up to unlock)
Unlock all 12 October questions, free
No credit card. Every question with its framework, the grading signals interviewers score against, and a worked answer for each.
Interview tracks at October
How October's DNA translates across functions. Pick your role.
October resume and cover letter
Applications to October go through an applicant tracking system, which parses your resume before a recruiter reads it. Keep the layout plain and describe your skills in the words of the posting. The interviews usually run in English, so send your resume and cover letter in English unless the posting asks for another language. Give each point in the October DNA above a bullet that proves it.
Check your resume against the October job posting
Upload your resume with the October job description to see your ATS score, the keywords you are missing and what to fix before you apply.
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Write your October cover letter
Drafted from your resume and the October posting, so it names what you actually did. You edit it before you send it.
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Compare October with similar employers
Same DNA, different bar. Browse the closest companies in our database and see how their loops differ.
TrueLayer
Same tierTrueLayer's open banking infrastructure relies on high-throughput API integrations and resilient payment processing, ...
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Limetax
Same tierTax compliance edge cases and fiscal schema accuracy anchor evaluation at Limetax, alongside clean UI execution using...
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Qomodo
Same tierQomodo's interview loop, often involving Founder Michele Attisani, grades for a candidate's capacity to distill compl...
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Practice October interviews end-to-end
October Mock Interview
Run a live mock interview with our AI interviewer using October-style prompts. Get scored on structure, signal, and answer length - exactly how the real loop grades you.
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STAR Stories for October Behavioral Rounds
Build a Story Bank of your past wins, mapped to the leadership signals October interviewers grade on. Reuse them across every behavioral round.
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October Interview Prep Hub
The frameworks behind every October round: CIRCLES for product sense, hypothesis-driven debugging for analytical, STAR for behavioral. Learn each one in 10 minutes.
Open
Interview Frameworks
CIRCLES, STAR, AARRR, RICE, MECE. The exact frameworks that make October interviewers nod instead of frown. Step-by-step playbooks with the moves and the pitfalls.
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Sample answers
What a strong answer to these October interview questions shows.
Given a list of loan applications, each with an amount, interest rate, and a submission timestamp, write a function to calculate the total approved loan amount for a given day, considering that applications are approved sequentially and a loan is only approved if its amount is less than or equal to the remaining available capital for that day. Assume a fixed daily capital pool.
A strong answer shows: Clear and efficient algorithm design.; Correct implementation of the approval logic and capital management.; Consideration of edge cases and input validation..
Describe a complex bug you encountered in a production system. Walk me through your process of diagnosing and fixing it, and what steps you took to prevent similar issues in the future.
A strong answer shows: Detailed explanation of the bug and its impact.; Clear, step-by-step description of the debugging process.; Effective and specific preventative measures implemented.; Understanding of production system stability..
Frequently asked questions
How many interview rounds does October run for Software Engineer candidates?
5 rounds, in this order: Recruiter Screen, Coding Screen, System Design, Onsite Coding, and Behavioral / Leadership.
What does October look for in Software Engineer candidates?
October's 'Functional Always' principle underpins the evaluation, seeking candidates who demonstrate a deep understanding of financial product mechanics and can articulate how their work contributes to robust, scalable solutions for October Europe Access. They grade for practical application over theoretical knowledge.
In which language does October run its interviews?
October usually interviews in English.
How many October Software Engineer interview questions does JobMentis hold?
12 questions across the rounds of the October loop, last updated October 23, 2026.