How long does the ING interview process take?

Most candidates spend between 4 and 8 weeks from recruiter screen to offer. The onsite loop itself runs in a single day or is split across two half-days, with debrief and offer typically within 5 business days after.

How should I prepare specifically for ING?

Focus on three things: (1) the company DNA shown above — what they actually grade for, (2) the rounds in your loop, especially the round most candidates underestimate, and (3) drilling on the question types in this guide using a structured framework like CIRCLES or STAR.

Does this apply to engineering or design roles at ING?

The DNA stays the same — what changes is the round mix. SWE candidates face coding screens instead of Product Sense; designers face portfolio reviews and design exercises. The "what they value" and behavioral signals carry across all functions.

Why are you interested in joining ING as a Software Engineer, and what aspects of our work in financial technology particularly appeal to you?

Type: Motivation. Sign up at JobMentis to see the full framework, grading signals, and worked answer for this question.

Implement a function that takes a list of stock prices for a single stock over several days and returns the maximum profit that could have been made by buying and selling the stock once. If no profit can be made, return 0.

Type: Algorithmic. Sign up at JobMentis to see the full framework, grading signals, and worked answer for this question.

Design a system to process and store real-time stock market data feeds from multiple exchanges. The system should be able to handle high throughput, provide low-latency access to recent data, and support historical data analysis.

Type: System Design. Sign up at JobMentis to see the full framework, grading signals, and worked answer for this question.

Design an API rate limiter for a banking application's public API. Consider different strategies (e.g., token bucket, leaky bucket) and how to handle distributed systems.

Type: System Design. Sign up at JobMentis to see the full framework, grading signals, and worked answer for this question.

Given a binary tree where each node represents a financial account balance, write a function to find the maximum sum of balances along any path from the root to a leaf. Handle cases with negative balances.

Type: Algorithmic. Sign up at JobMentis to see the full framework, grading signals, and worked answer for this question.

Here is a code snippet that attempts to calculate compound interest. It's producing incorrect results for certain inputs. Find the bug(s) and explain how to fix them.

Type: Debugging. Sign up at JobMentis to see the full framework, grading signals, and worked answer for this question.

Tell me about a time you took ownership of a project or problem that was not explicitly assigned to you. What was the situation, what did you do, and what was the outcome?

Type: Ownership. Sign up at JobMentis to see the full framework, grading signals, and worked answer for this question.

Describe a time you had to influence a stakeholder or team who disagreed with your proposed product direction. How did you approach it, and what was the result?

Type: Influence. Sign up at JobMentis to see the full framework, grading signals, and worked answer for this question.

Other roles at ING:IB Analyst Product Manager Software Engineer

Enterprise · Software Engineer Interview Guide

How to Pass the ING Software Engineer Interview in 2026

The ING DNA (TL;DR)

ING values a strong sense of ownership and a pragmatic, results-oriented approach to problem-solving. They look for candidates who can demonstrate a clear understanding of business impact and can articulate how their technical contributions drive value for the company and its customers.

The ING Interview Loop

Your onsite loop will typically consist of 5 rounds.

1
Round 1
Recruiter Screen
Motivation, role fit, logistics.
2
Round 2
Coding Screen
LeetCode-medium algorithmic problems under time pressure.
3
Round 3
System Design
Distributed systems, trade-offs at scale, architecture under constraints.
4
Round 4
Onsite Coding
LeetCode-hard, debugging, code clarity, edge cases.
5
Round 5
Behavioral / Leadership
Past evidence of ownership, influence, resolving conflict.

The Danger Zone: Top Reasons Candidates Fail

Based on our database of ING interview outcomes, avoid these common traps:

Not proposing alternative solutions or compromises.
Not demonstrating concrete steps taken to prevent recurrence.
Focusing only on the disagreement without explaining their influence strategy.
Describing a situation where they simply 'won' the argument without collaboration.

Test Yourself: Real ING Questions

Three real prompts pulled from our database.

Type · System Design

Design a distributed cache for frequently accessed customer account data to reduce database load. What are the trade-offs between consistency models (e.g., strong vs. eventual)?

Type · Algorithmic

Given a list of financial transactions, each with a timestamp, amount, and currency, write a function to calculate the total balance for a given currency over a specified time range. Assume timestamps are Unix epoch seconds.

Type · Behavioral

Tell me about a time you made a mistake or a significant error in your work. How did you handle it, and what did you do to prevent it from happening again?

+ many more questions, signals, and worked examples

Unlock the rubric →

ING Interview Question Bank

A sample from our database, grouped by round. Sign up to see the full set.

9 of 17 questions shown

Recruiter Screen

1
Type · Motivation
Why are you interested in joining ING as a Software Engineer, and what aspects of our work in financial technology particularly appeal to you?

Coding Screen

2
Type · Algorithmic
Given a list of financial transactions, each with a timestamp, amount, and currency, write a function to calculate the total balance for a given currency over a specified time range. Assume timestamps are Unix epoch seconds.
3
Type · Algorithmic
Implement a function that takes a list of stock prices for a single stock over several days and returns the maximum profit that could have been made by buying and selling the stock once. If no profit can be made, return 0.
+ 1 more questions in this round (sign up to unlock)

System Design

4
Type · System Design
Design a system to process and store real-time stock market data feeds from multiple exchanges. The system should be able to handle high throughput, provide low-latency access to recent data, and support historical data analysis.
5
Type · System Design
Design an API rate limiter for a banking application's public API. Consider different strategies (e.g., token bucket, leaky bucket) and how to handle distributed systems.
+ 2 more questions in this round (sign up to unlock)

Onsite Coding

6
Type · Algorithmic
Given a binary tree where each node represents a financial account balance, write a function to find the maximum sum of balances along any path from the root to a leaf. Handle cases with negative balances.
7
Type · Debugging
Here is a code snippet that attempts to calculate compound interest. It's producing incorrect results for certain inputs. Find the bug(s) and explain how to fix them.
+ 1 more questions in this round (sign up to unlock)

Behavioral / Leadership

8
Type · Ownership
Tell me about a time you took ownership of a project or problem that was not explicitly assigned to you. What was the situation, what did you do, and what was the outcome?
9
Type · Influence
Describe a time you had to influence a stakeholder or team who disagreed with your proposed product direction. How did you approach it, and what was the result?
+ 4 more questions in this round (sign up to unlock)

Unlock the full ING question bank

Free signup, no credit card. You get every question + the framework, grading signals, and worked answer for each.

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Interview tracks at ING

How ING's DNA translates across functions. Pick your role.

Software Engineers at ING should showcase a pragmatic approach to building robust and scalable systems, with a keen eye on security and compliance. Expect to be evaluated on your problem-solving skills, your ability to write clean, maintainable code, and your understanding of how your technical decisions impact the bank's operational efficiency and customer experience in areas like digital banking and payments.

System Design

Design a distributed cache for frequently accessed customer account data to reduce database load. What are the trade-offs between consistency models (e.g., strong vs. eventual)?

Algorithmic

+ 1 more

Unlock the Software Engineer grading rubric for ING

See full Software Engineer guide