Trustly Software Engineer interview questions & guide 2026

The following questions are representative of those asked during the Trustly interview process. While your specific experience may vary based on the team and seniority level, these patterns reflect the core competencies the hiring team evaluates.

Technical & Domain Knowledge

These questions assess your foundational understanding of software engineering, specifically within the Java and SQL ecosystems prevalent at Trustly.

• What are the differences between HashMap, TreeMap, and other Map implementations in Java?
• Explain the difference between a List, Set, and Map.

Preparation at Trustly requires a balance of deep technical mastery and clear, structured communication. You should approach your preparation by focusing on the "why" and "how" behind your technical decisions, rather than just the "what."

Role-Related Knowledge – This is your baseline. You must be comfortable explaining the internals of the languages and frameworks you use (specifically Java). Interviewers want to see that you understand the trade-offs of different data structures and design patterns.

Problem-Solving Ability – You will be evaluated on your ability to decompose complex, ambiguous requirements into actionable technical designs. Practice verbalizing your thought process as you work through system design problems; the "how" you arrive at a solution is often more important than the final result.

Leadership & Communication – Even in individual contributor roles, Trustly values the ability to influence and collaborate. Be ready to share concrete examples of how you have resolved conflicts, managed deliverables under pressure, or mentored peers.

Culture Fit – Trustly prioritizes candidates who are curious, communicative, and team-oriented. Demonstrating that you are a lifelong learner and that you can work effectively in an agile, fast-paced environment is essential.

The interview process at Trustly is designed to be rigorous, thorough, and data-driven. Candidates typically move through a series of stages that prioritize both technical aptitude and cultural alignment. You should expect a pace that is relatively fast, with clear communication from the recruiting team regarding timelines.

The process often begins with a recruiter screening, followed by objective assessments such as coding challenges or psychometric tests. Once you move past the initial screening, you will engage in technical interviews with peers and leadership. The focus is on evaluating your real-world problem-solving skills rather than rote memorization.

The visual timeline above illustrates the progression from initial screening to technical assessments and final management interviews. Use this to pace your study sessions and ensure you are mentally prepared for both the technical coding rounds and the more conversational behavioral discussions.

Technical Proficiency

This is the most critical evaluation area. You are expected to demonstrate high fluency in your primary programming language and a deep understanding of computer science fundamentals.

Be ready to go over:

• Data Structures and Algorithms – Expect to demonstrate your ability to optimize code and choose the right structure for the problem.
• Design Patterns – Be prepared to discuss common patterns (e.g., Singleton, Factory, Strategy) and when to use them.

As a Software Engineer at Trustly, your primary responsibility is the design, development, and maintenance of high-performance payment systems. You will translate complex business requirements into scalable technical solutions that facilitate secure transactions across borders.

You will work closely with product and operations teams to understand the friction points in the payment experience and build features that solve them. This often involves working on distributed systems, optimizing backend services, and ensuring that security is baked into every layer of the architecture.

Beyond coding, you will be expected to participate in code reviews, contribute to technical documentation, and mentor less experienced engineers. You are not just a developer; you are a stakeholder in the reliability and success of the Trustly platform.

A strong candidate for Software Engineer at Trustly combines deep technical expertise with a pragmatic, business-focused mindset.

• Technical Skills – Proficiency in Java is highly preferred. Experience with SQL and relational databases is a must. Familiarity with cloud infrastructure, microservices, and Agile methodologies is standard for most teams.
• Experience Level – While requirements vary, a strong understanding of full-stack development or specialized backend architecture is typically required.
• Soft Skills – Excellent communication in English is essential, as Trustly operates globally. You must be able to explain complex technical concepts to non-technical stakeholders clearly.

Q: How long does the interview process typically take? A: Candidates generally report that the process takes anywhere from two weeks to two months, depending on the role level. The team aims to be efficient, but rigor is prioritized.

Q: Should I expect live coding? A: Yes, be prepared for both take-home technical challenges and live coding or design discussions. Practice writing code in a clean, professional environment.

Q: How can I stand out during the behavioral interviews? A: Focus on being transparent about your successes and failures. Trustly values humbleness, honesty, and a growth mindset.

Q: Is the technical test the most important part? A: It is a critical gateway. If you do not pass the automated technical assessments, you may not progress to the conversation stage, so take these tests seriously.

• Master the fundamentals: Don't just learn a framework; understand the underlying language features (like Java collection internals).
• Be prepared for English assessments: Since Trustly is an international company, your ability to communicate effectively in English is evaluated throughout the process.
• Focus on the "Why": When explaining your past projects, emphasize the business value and the trade-offs you made during the design phase.
• Prepare for the "Why Trustly" question: Have a clear, articulated reason for why you want to work in the fintech space and why Trustly specifically interests you.

The Software Engineer role at Trustly is an opportunity to work on high-impact infrastructure that powers global commerce. Success in the interview process requires a blend of technical depth, especially in Java and system design, and the ability to articulate your experiences clearly and honestly. By focusing on fundamental engineering principles and preparing thoughtful examples of your past work, you will be well-positioned to succeed.

You can explore additional interview insights, practice questions, and preparation resources on Dataford to further sharpen your skills. Preparation is the single most effective way to manage the rigor of this process and enter your interviews with confidence.

This module provides an overview of expected compensation, including base salary and potential bonuses. Use this data to benchmark your expectations and understand the market value for this role, keeping in mind that total compensation packages often vary based on your specific level of experience and location.