N26

N26's Interview Process (2026)

Blog / N26's Interview Process (2026)

N26's software engineer interview process is a structured multi-stage pipeline that typically takes 3 to 6 weeks from application to offer. Most candidates go through around five or six rounds covering a take-home challenge, live coding, system design, and a behavioral interview.

Recruiter Screen: A short call, usually around 15 to 30 minutes, covering your background, salary expectations, and any relocation needs for N26's offices in Berlin, Barcelona, or Madrid.
Technical Assessment: A take-home challenge or timed Codility task, typically involving a backend API problem. Most candidates report having 48 hours to a week to submit.
Technical Deep Dive: A 45 to 60 minute walkthrough of your submitted code with two senior engineers. Expect to justify every design decision rather than just present it.
Live Coding / Pair Programming: A hands-on coding session, usually around 45 to 60 minutes, focused on practical banking-related problems where communication and edge case awareness matter as much as the solution.
Theoretical Technical and System Design: A 45 to 60 minute round testing architectural trade-offs and deeper implementation knowledge, often touching on topics like pagination strategies and database performance at scale.
Behavioral and Culture Fit: A final conversation with a Hiring Manager or Head of Engineering, using a structured rubric to assess how you think about trade-offs between speed, security, and quality.

To prepare effectively, focus your study plan across these key areas that N26 consistently tests throughout its process:

Take-Home Project: A backend API challenge emphasizing thread safety, clean architecture, and testability.
Low-Level Design: Object-oriented design and production-grade code reviewed and defended in the deep dive round.
Data Structures and Algorithms: Practical coding problems grounded in banking scenarios, tested in the live coding round.
System Design: Architectural trade-offs, microservices, and topics like pagination at scale.
Behavioral: Structured questions about past decisions, trade-offs, and how you think about product and engineering.

1. Take-Home ProjectThe most common take-home task in 2025 and 2026 is building a RESTful API for real-time transaction statistics, similar to the Transaction Statistics challenge. The key constraint is handling high-volume concurrent updates in memory without a traditional database, which means you need to think carefully about thread-safe data structures from the start.N26 interviewers have explicitly said they prefer clean, readable, well-tested code over clever algorithmic tricks. Prioritize meaningful test coverage and separation of concerns over micro-optimizations.Be ready to explain why you chose specific data structures or libraries. Saying you used something because it is the standard approach is often viewed negatively. They want to see a deliberate, justified choice. For practice with similar problems, check out take-home project practice.

2. Low-Level DesignThe Technical Deep Dive is essentially a code defense, not a presentation. Engineers will probe your submitted code with questions like 'What happens if the service restarts?' or 'How would this handle 10x the load?' so you need to have thought through failure modes before you walk in.N26 places a strong emphasis on SOLID principles and test-driven development. Problems like the Thread-Safe Account Ledger, Account Management Service, and Transaction Service are good representations of the kind of design thinking they look for.You may also encounter scenarios around transaction state management or categorization. The Transaction State Machine and Transaction Categorization Service are worth working through to sharpen your design instincts.

3. Data Structures and AlgorithmsThe live coding round at N26 is not LeetCode-style brain teasers. Problems are grounded in banking scenarios like implementing a balance calculator that handles concurrent operations or building a simple account management service. Expect to talk through your thinking out loud and catch edge cases like negative transaction amounts.Topics like prefix sums, heaps, and graph traversal come up in candidate reports. Problems such as Range Sum Queries (Prefix Sums), Top K Highest Numbers in a Stream, and Graph Level Order Traversal are solid starting points.For broader preparation, work through our 100 most commonly asked DSA questions and make sure you are comfortable with trees and sliding-window techniques, both of which appear in N26-related problem sets.

4. System DesignThe theoretical technical round in 2026 focuses on implementation depth rather than just drawing architecture diagrams. A recurring topic is pagination for a banking ledger, where you are expected to compare LIMIT/OFFSET, Keyset (Seek method), and Cursor-based pagination and explain how each affects database performance at scale.Avoid suggesting fetching all records and paginating in memory. This is a well-known failure point in this round. Be ready to discuss database indexing as part of your answer.N26's broader system design questions often touch on microservices orchestration, event-driven architecture with Kafka, and handling offline states for mobile clients. Practice with our High-Level Design case studies and use the System Design Whiteboard to get comfortable structuring your thinking under time pressure.

5. BehavioralN26 uses a structured rubric in the behavioral round, so vague answers will not land well. Expect questions like 'Tell me about a time you had to balance shipping a feature quickly versus regulatory or security constraints.' Structure your answers using the STAR principle to keep your responses focused and concrete.N26 also asks product-aware questions like 'How would you improve N26's onboarding conversion rate from a technical perspective?' Doing your homework on their recent product launches, such as eSIMs, Under-18 accounts, and Stocks/ETFs, and connecting your technical decisions to those user-facing features can set you apart.For a full set of question patterns and answer frameworks, the Behavioral Interview Course and Behavioral Playbook are both worth going through before this round.

ConclusionN26's process rewards engineers who write clean, well-reasoned code and can defend their choices under scrutiny. Focus on the take-home quality, get comfortable with pagination trade-offs, and tie your answers back to fintech context wherever you can. Follow the N26 Interview Roadmap for a structured, stage-by-stage prep plan to move from first screen to offer.