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N26 careers and interviews, from the Codility test to the design round.

Updated · Sources at the end

N26's engineering loop has a fixed order that its own backend job ads have listed: a recruiter screen, a Codility test, pair coding, systems design and a behavioural interview. The Codility test is the gate most candidates write about. It mixes a task where you fix someone else's buggy function with two algorithm problems, and candidates report you can pass without a perfect score. The pair coding and design rounds are each about an hour with two N26 engineers, often on the same day, and the design prompts come from banking: accounts, transfers and payments that must never run twice. Candidates also report slow or thin feedback, so this guide covers how to keep the process moving as well as how to pass it.

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01

Who N26 hires

N26 is a German bank with a full banking licence, run from Berlin with tech hubs in Barcelona and Vienna. It says it has about 1,600 employees from more than 90 nationalities and works in 24 markets. Engineering builds the apps and the backend behind them: about 200 microservices by its own 2022 count, mostly Kotlin on the JVM, on AWS. Hiring is much quieter than in its growth years. On 16 October 2026 N26's own board showed 35 open jobs, and only two were engineering roles: a Junior Android Engineer in the Payments team (Kotlin, coroutines, Jetpack Compose, test-driven development) in Berlin or Barcelona, and an IT Solutions Engineer for its Google Cloud and Workspace estate. A Lead Technical Product Manager for the machine learning platform, which scores fraud and credit risk in real time, was also open. Backend roles in Berlin and Barcelona were advertised through 2025, so the loop below is the one to prepare for when they come back.

Wondering whether your resume reads like someone N26 hires? Get a free resume review.

Backend and most engineering roles share one loop. Mobile and data roles swap in their own exercise.

  • Track · Backend

    Backend and software engineering

    The loop N26's backend ads have listed: recruiter screen, Codility test, pair coding, systems design and a behavioural interview. Pair coding and systems design are each about an hour with two engineers, and candidates often sit them on the same day with a break between.

  • Track · Mobile

    Android and iOS

    Recent Android reports describe a Codility test with mostly easy tasks on Android and data handling, a discussion of a past project with two engineers, then about 90 minutes of live coding in which you add a feature to an Android app. Older iOS reports describe an online test and a take-home app with a four-day deadline, followed by a long technical interview about your code.

  • Track · Data

    Data science

    Candidates report a first conversation about their background, then a case study to finish in three to five days, often a business problem N26 faces, which they present. A technical interview with a data scientist follows, and some report a final conversation with a senior tech leader.

02

What is the N26 interview process?

N26 publishes no general page on how it hires. The steps below come from its own backend job ads, which named them in order, and from candidate reports on Glassdoor seen in search snippets. Candidates report the whole process taking a few weeks, and several report long waits between stages.

01
Recruiter screen
15 to 30 minutes by video

Your background, why N26, your notice period, salary expectations and whether you need relocation or a visa. N26's ads offer a relocation package with visa support.

02
Codility test
Online, in your own time within a set window

Usually three tasks: fix the bugs in a short function, then two algorithm problems at about LeetCode medium level. Candidates report about two hours of work and a window of a few days to a week.

03
Pair coding
About an hour with two N26 engineers

Some candidates get pre-written code with tests and must read the requirements, run the tests, fix what fails and add the tests that are missing. Others get a medium algorithm problem. Either way you talk through edge cases as you go.

04
Systems design
About an hour with two other engineers

A high-level design from the banking domain, such as a store for accounts and transactions or the path of a payment. Reported follow-ups include asynchronous communication between microservices and scaling.

Backend and senior roles
05
Live feature build
About 90 minutes

Adding a feature to an existing Android app, with short discussions of architecture along the way.

Android
06
Case study and presentation
Three to five days, then a presentation

A business problem to solve end to end and present, followed by theoretical and applied questions from a data scientist.

Data science
07
Behavioural interview
45 to 60 minutes with the hiring manager

How you work: conflict in a team, mentoring others, delivering under a deadline, and taking feedback.

03

N26 Codility test: questions and answers

Reported problems and how to solve them

The Codility test is the second step in N26's engineering loop and the one most candidates describe. Reports seen in search snippets agree on the shape: usually three tasks, one where you fix the bugs in a short function and two algorithm problems at about LeetCode medium level. Candidates report about two hours of work and a deadline of a few days to a week. Android candidates report easier tasks closer to their platform. The tasks rotate, so prepare for the patterns below; the exact problems may differ.

  • The bug-fix task: You get a short function that is meant to do one thing and fails on some inputs. A reported example checks whether an array holds exactly the numbers 1 to K. Read the specification twice, write the edge cases down before you edit anything (empty input, K bigger than the array, values outside 1 to K, repeats), and change as few lines as you can. Codility bug-fix tasks often limit how many lines you may change.
  • Two medium algorithm problems: Candidates call them LeetCode medium, and some name dynamic programming. Practise arrays, strings, hash maps, sliding windows and simple dynamic programming on Codility's own free lessons, since the editor and the hidden tests behave differently from LeetCode.
  • Correctness and speed are both scored: Codility runs hidden tests for correctness and for performance on large inputs. A brute-force answer can pass the visible examples and still lose half its points. State the complexity to yourself before you submit and test a large input.
  • You can pass without a perfect score: One candidate reports that N26 looks for about two thirds correctness. Do not spend your last hour polishing one problem while another is blank: get each task to a working, tested answer first.
  • Write it as if someone will read it: N26's engineering ads ask for code that is well tested and well documented. Clear names and small functions cost you nothing in the test, and they are the habits the pair coding round watches for.
  • Your own work only: One candidate reports a rejection for code N26 judged copied from elsewhere, without a chance to explain. Write the solution yourself, and keep your notes or scratch work in case you are asked how you got there.

N26 does not publish the test's contents. Ask your recruiter how many tasks there are, how long the window is and which language you may use.

The rest of the loop depends on your role. Pick it, or paste the posting, and Calibrd predicts the rounds and questions you are likely to get at N26.

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04

What N26 screens for

N26's engineering ads describe the same traits again and again, and the behavioural interview listens for them.

  • Asking why, and being ready to be asked what you think: the ads use almost these words
  • A strong bias for action and getting things done
  • Code that is well tested and well documented, with test-driven development named in the mobile ads
  • Giving and receiving open, direct and timely feedback
  • Ownership: the ads ask you to understand how the whole product fits together inside a cross-functional team
  • Security and compliance: the ads stress strict financial regulation, and BaFin has had a special monitor at the bank since 2025
05

N26 interview questions

Candidate-reported themes

Candidates report behavioural questions on conflict, mentoring and deadlines, and technical questions drawn from banking. The questions below follow those reports and the traits in N26's own job ads.

Behavioural & motivation

  • Why N26, and why a bank?Listening for: Specificity · Connection · Research
  • Tell me about a time you disagreed with a teammate about a technical decision.Listening for: Engagement · Professionalism · Resolution
  • Tell me about a time you helped a less experienced engineer grow.Listening for: The person · How they helped · The change
  • Tell me about a time a deadline forced you to choose between shipping fast and shipping safely.Listening for: The trade-off · The decision · The outcome
  • Tell me about feedback you received that changed how you work.Listening for: The feedback · What changed · Giving it back

Technical

  • Practice: a function should return true only if an array contains every number from 1 to K and nothing else. It passes the happy path but fails some inputs. How do you find and fix the bugs?Fixing someone else's code: Reported in the Codility test: a short function that should check whether an array holds exactly the numbers 1 to K, with bugs to fix. A practice question in that styleListening for: Reads the spec · Edge cases · Small fix
  • Practice: given a list of daily account balances, find the longest run of days in which the balance never went down. Walk through your approach and its complexity.Medium algorithms: Two medium problems in the Codility test, and sometimes one in pair coding. Candidates name dynamic programming among them. A practice question in that styleListening for: Approach · Complexity · Edge cases
  • Practice: you're handed a small service that applies card fees, with three passing tests and one failing. What do you do in the first ten minutes?Tests in pair coding: Candidates describe pre-written code with tests: read the requirements, run the tests, fix the failures and add the missing testsListening for: Reads first · Fixes the failure · Finds gaps
  • Practice: design the service that moves money between two N26 accounts. How do you make sure a transfer never happens twice and never loses money?Banking system design: Reported design rounds are about one hour and set in the banking domain, with follow-ups on async messaging between microservices and on scale. A practice question in that styleListening for: Ledger · No double runs · Failure handling
  • Practice: why would a bank move its JVM services from Java to Kotlin, and what would you watch for in the migration?Kotlin and the JVM: N26's backend ads asked for a JVM language with Spring Boot in production, Kotlin as a plus, Postgres and AWSListening for: Why Kotlin · Java interop · Rollout

These are the reported themes, and your loop is role-specific. Paste the actual posting and Calibrd predicts the questions for that exact role and level. How the questions are predicted →

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06

How to prepare for a N26 interview

  1. Read the job ad for the team (Payments, Investments, Lending, Core Banking) and prepare one example of a system you built in that kind of domain.
  2. Do Codility's free lessons and two or three timed practice tests so the editor and its hidden tests hold no surprises.
  3. Practise bug-fix tasks: take a short function, break it on purpose, and fix it while changing as few lines as possible.
  4. Solve medium problems on arrays, strings, hash maps and simple dynamic programming, and say the complexity out loud each time.
  5. Practise pair coding on a codebase you didn't write: read the tests first, fix a failing one, then add a missing one, talking the whole time.
  6. Prepare one banking design end to end: a ledger of account movements, idempotent transfers, and what happens when a service fails halfway.
  7. Brush up on Kotlin, Spring Boot, Postgres and messaging between microservices, since backend ads ask for them.
  8. Have short stories ready on a conflict, mentoring someone, a deadline trade-off and feedback you acted on.
  9. Ask the recruiter at each stage when you will hear back, and follow up politely on that date. Candidates report long silences.
  10. N26's ads publish no pay, so ask for the range on the first call and say whether you need relocation or a visa.

This guide covers N26's software engineering loop, with notes on its Android, iOS and data science interviews. For management and leadership roles the loop is similar but the bar shifts to people, delivery and strategy, so pair it with the leadership interview prep hub. The bar for your exact role comes from the role-by-role guides, and the prep that actually transfers is spoken, so run a mock interview before the real one.

Also interviewing at Trade Republic, Goldman Sachs or JPMorgan Chase? Their guides follow the same format, from the first screen to the offer.

Knowing the questions isn’t the same as answering them out loud. Run a N26 mock: spoken answers, coached on the spot. Your first mock is free.

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07

FAQ & sources

What is N26's interview process?

N26 publishes no general page on how it hires. The stages, in order: Recruiter screen; Codility test; Pair coding; Systems design; Live feature build; Case study and presentation; Behavioural interview.

What does N26 look for in candidates?

N26's engineering ads describe the same traits again and again, and the behavioural interview listens for them. Asking why, and being ready to be asked what you think; A strong bias for action and getting things done; Code that is well tested and well documented, with test-driven development named in the mobile ads; Giving and receiving open, direct and timely feedback.

What questions does N26 ask in interviews?

Candidates report behavioural questions on conflict, mentoring and deadlines, and technical questions drawn from banking. Technical themes: Fixing someone else's code; Medium algorithms; Tests in pair coding; Banking system design; Kotlin and the JVM.

What is on the N26 Codility test?

The Codility test is the second step in N26's engineering loop and the one most candidates describe. Reports seen in search snippets agree on the shape: usually three tasks, one where you fix the bugs in a short function and two algorithm problems at about LeetCode medium level. Covered on this page: The bug-fix task; Two medium algorithm problems; Correctness and speed are both scored; You can pass without a perfect score; Write it as if someone will read it; Your own work only.

How do I prepare for a N26 interview?

Read the job ad for the team (Payments, Investments, Lending, Core Banking) and prepare one example of a system you built in that kind of domain. Do Codility's free lessons and two or three timed practice tests so the editor and its hidden tests hold no surprises.

Interview processes change. This reflects widely-reported and sourced conditions as of 2026 — confirm specifics with your recruiter, and treat it as a map rather than a guarantee.

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