Reef Software Engineer Interview Guide

Getting ready for a Software Engineer interview at Reef? The Reef Software Engineer interview process typically spans 4–6 question topics and evaluates skills in areas like algorithm design, data structures, system architecture, and problem-solving with real-world business context. Interview preparation is especially important for this role at Reef, as candidates are expected to demonstrate their ability to build scalable solutions, tackle ambiguous challenges, and communicate technical decisions clearly—all while contributing to Reef’s mission of transforming urban spaces through technology-driven platforms.

In preparing for the interview, you should:

• Understand the core skills necessary for Software Engineer positions at Reef.
• Gain insights into Reef’s Software Engineer interview structure and process.
• Practice real Reef Software Engineer interview questions to sharpen your performance.

At Interview Query, we regularly analyze interview experience data shared by candidates. This guide uses that data to provide an overview of the Reef Software Engineer interview process, along with sample questions and preparation tips tailored to help you succeed.

Reef is a leading operator of urban real estate and logistics hubs, transforming underutilized city spaces into vibrant centers for commerce, community, and services. The company specializes in leveraging technology to optimize last-mile delivery, urban logistics, and neighborhood-focused experiences. Serving a wide range of industries, including food, retail, and mobility, Reef aims to connect people, businesses, and cities for a more sustainable urban future. As a Software Engineer at Reef, you will contribute to building scalable digital solutions that power these urban ecosystems and support the company’s mission of revitalizing city life.

As a Software Engineer at Reef, you will be responsible for designing, developing, and maintaining software solutions that support the company’s digital infrastructure and services. You will collaborate with cross-functional teams, including product managers and designers, to build scalable applications, improve system performance, and deliver new features. Typical responsibilities include writing clean, efficient code, troubleshooting technical issues, and participating in code reviews to ensure high-quality standards. This role is instrumental in driving innovation and operational efficiency, helping Reef deliver reliable technology solutions to enhance its business offerings.

2.1 Stage 1: Application & Resume Review

The process begins with an initial screening of your application materials, focusing on your experience with software engineering fundamentals, proficiency in programming languages (such as Python, Java, or JavaScript), and exposure to scalable system design and data-driven problem solving. The hiring team will look for evidence of technical competency, project ownership, and experience with collaborative development environments. To prepare, ensure your resume highlights relevant technical skills, impactful projects, and any experience with distributed systems, cloud platforms, or product-focused engineering.

2.2 Stage 2: Recruiter Screen

Next, a recruiter from Reef will invite you for a brief phone or video conversation. This stage is designed to gauge your interest in Reef, clarify your understanding of the role, and assess your general fit with the company’s mission and values. Expect questions about your motivation for applying, your previous engineering experience, and your ability to thrive in a dynamic, cross-functional team. Preparation should include a clear articulation of your career goals, why Reef appeals to you, and how your background aligns with the company’s focus on innovative technology solutions.

2.3 Stage 3: Technical/Case/Skills Round

At this stage, you’ll encounter one or more technical interviews, which may include coding challenges, algorithmic problem-solving, and system design exercises. Interviewers—typically software engineers or engineering managers—will evaluate your ability to write clean, efficient code, reason through complex problems, and design scalable solutions. You may be asked to implement algorithms (such as shortest path or binary tree validation), optimize existing code, or discuss approaches to real-world engineering scenarios (like building data pipelines or modeling new features). Preparation should include practicing coding under time constraints, revisiting core computer science concepts, and reviewing system design patterns relevant to product engineering.

2.4 Stage 4: Behavioral Interview

This round focuses on your interpersonal skills, collaboration style, and ability to navigate challenges within engineering teams. You’ll speak with engineering leaders or cross-functional partners about your experience working on team projects, communicating technical insights to non-technical stakeholders, and handling setbacks or conflicts. Expect to discuss times you exceeded expectations, managed stakeholder communication, or drove process improvements. Prepare by reflecting on concrete examples from your career that demonstrate adaptability, initiative, and a commitment to continuous learning.

2.5 Stage 5: Final/Onsite Round

The final round typically consists of a series of interviews with key team members, including senior engineers, product managers, and possibly executives. You’ll be assessed on your technical depth, product intuition, and cultural fit. Sessions may include advanced coding or system design problems, technical presentations, and scenario-based discussions about building and scaling software products. You may also be asked to analyze feature performance or propose solutions to real business challenges. Preparation should center on synthesizing your technical expertise with product thinking and stakeholder engagement, as well as demonstrating your ability to contribute to Reef’s engineering culture.

2.6 Stage 6: Offer & Negotiation

If successful, you’ll receive an offer from Reef’s recruiting team. This stage involves discussing compensation, benefits, and onboarding logistics. You may have the opportunity to negotiate terms and clarify your role within the engineering organization. Preparation should include researching market compensation benchmarks and prioritizing aspects of the offer that matter most to you, such as growth opportunities, team structure, and work-life balance.

2.7 Average Timeline

The typical Reef Software Engineer interview process takes approximately 3-5 weeks from initial application to final offer. Fast-track candidates with highly relevant experience or strong internal referrals may complete the process in as little as 2-3 weeks, while standard candidates generally experience about a week between each stage. Coordination of technical and onsite rounds may vary depending on team availability and scheduling preferences.

Now, let’s dive into the specific interview questions you might encounter at Reef for the Software Engineer role.

3.1 Algorithms & Data Structures

Expect questions that test your ability to design, implement, and optimize algorithms for real-world scenarios. You should be comfortable with classic problems, as well as structuring code for scalability and maintainability.

3.1.1 Create your own algorithm for the popular children's game, "Tower of Hanoi"
Describe the recursive logic and base case, then walk through how your implementation manages disk moves and state. Emphasize clarity and efficiency in your approach.
Example answer: "I’d use recursion to move disks between rods, ensuring only smaller disks are placed on larger ones, and optimize by minimizing redundant moves."

3.1.2 Given the root node, verify if a binary search tree is valid or not
Explain your traversal strategy, such as in-order traversal, and how you check node relationships to validate BST properties.
Example answer: "I traverse the tree in-order and ensure each node value is greater than the previous, confirming BST validity."

3.1.3 The task is to implement a shortest path algorithm (like Dijkstra's or Bellman-Ford) to find the shortest path from a start node to an end node in a given graph. The graph is represented as a 2D array where each cell represents a node and the value in the cell represents the cost to traverse to that node.
Discuss your choice of algorithm, how you manage node states, and how you optimize for time and space complexity.
Example answer: "I’d use Dijkstra’s algorithm, keeping a priority queue to track minimal path costs and updating neighbors efficiently."

3.1.4 Given an array of non-negative integers representing a 2D terrain's height levels, create an algorithm to calculate the total trapped rainwater. The rainwater can only be trapped between two higher terrain levels and cannot flow out through the edges. The algorithm should have a time complexity of O(n) and space complexity of O(n). Provide an explanation and a Python implementation. Include an example input and output.
Break down your approach using two-pointer or stack techniques, and explain how you track left/right boundaries to compute trapped water.
Example answer: "I’d use two pointers to scan from both ends, updating max heights and summing trapped water between them."

3.2 Systems Design & Architecture

These questions assess your ability to design scalable, reliable systems and think through trade-offs in architecture and data flow. Focus on modularity, fault tolerance, and clarity in communication.

3.2.1 System design for a digital classroom service.
Outline the core components, data flow, and user roles, emphasizing scalability and user experience.
Example answer: "I’d design a modular backend with real-time messaging, secure authentication, and scalable storage for classroom resources."

3.2.2 Design a scalable ETL pipeline for ingesting heterogeneous data from Skyscanner's partners.
Discuss your approach to handling schema variability, error handling, and maintaining data quality at scale.
Example answer: "I’d use a modular ETL framework with schema validation, batching, and robust error logging for partner data."

3.2.3 Design an end-to-end data pipeline to process and serve data for predicting bicycle rental volumes.
Explain the stages from ingestion to model deployment, highlighting data cleaning, feature engineering, and serving predictions.
Example answer: "I’d build ETL jobs for data ingestion, use feature stores for preprocessing, and deploy models via REST APIs."

3.2.4 Aggregating and collecting unstructured data.
Describe techniques for parsing, normalizing, and storing unstructured content, and how you ensure data accessibility.
Example answer: "I’d use distributed processing for ingestion, schema mapping for normalization, and store in a scalable NoSQL database."

3.3 Machine Learning & Analytics

Be prepared to discuss your experience building, evaluating, and deploying machine learning models, as well as your ability to interpret and communicate results.

3.3.1 Build a random forest model from scratch.
Walk through the logic of decision trees, ensemble methods, and how you aggregate predictions for robust performance.
Example answer: "I’d implement bootstrapped sampling, build multiple decision trees, and average their outputs for final predictions."

3.3.2 The role of A/B testing in measuring the success rate of an analytics experiment
Explain experimental design, metrics selection, and how you interpret statistical significance for business decisions.
Example answer: "I’d define control and treatment groups, track conversion metrics, and use statistical tests to validate impact."

3.3.3 How to model merchant acquisition in a new market?
Discuss feature selection, predictive modeling, and how you’d use external signals to inform acquisition strategies.
Example answer: "I’d analyze market demographics, build logistic regression models, and incorporate competitor data for acquisition targeting."

3.3.4 Calculate the minimum number of moves to reach a given value in the game 2048.
Describe your approach for state space exploration, optimization, and pruning unnecessary paths.
Example answer: "I’d use BFS to explore moves, track visited states, and minimize steps to reach the target value efficiently."

3.3.5 How would you analyze how the feature is performing?
Outline your approach for defining success metrics, collecting usage data, and presenting actionable insights.
Example answer: "I’d monitor user engagement, conversion rates, and retention metrics, then visualize trends for stakeholder review."

3.4 Data Quality & Cleaning

These questions focus on your ability to manage, clean, and validate large datasets, ensuring reliability and accuracy for downstream applications.

3.4.1 Describing a real-world data cleaning and organization project
Share your process for identifying issues, applying cleaning techniques, and documenting transformations.
Example answer: "I start with profiling, then use scripts for deduplication, imputation, and maintain versioned cleaning logs."

3.4.2 How would you approach improving the quality of airline data?
Discuss strategies for profiling, validation, and iterative improvement of messy or incomplete datasets.
Example answer: "I’d audit for inconsistencies, set up automated quality checks, and collaborate with data owners for remediation."

3.4.3 Describing a data project and its challenges
Talk through a major data challenge, your troubleshooting steps, and the lessons learned for future projects.
Example answer: "I faced missing values and schema drift, resolved them with robust ETL and documented fixes for repeatability."

3.4.4 How to present complex data insights with clarity and adaptability tailored to a specific audience
Describe your strategy for translating technical findings into actionable business recommendations.
Example answer: "I tailor visualizations and summaries to audience expertise, focusing on business impact and next steps."

3.5 Behavioral Questions

3.5.1 Tell me about a time you used data to make a decision.
How to answer: Share a specific scenario where your analysis led directly to a business or product outcome. Focus on your thought process, the data you leveraged, and the impact of your decision.
Example answer: "I analyzed user engagement data and recommended a UI change that boosted retention by 15%."

3.5.2 Describe a challenging data project and how you handled it.
How to answer: Outline the technical and organizational hurdles, your approach to problem-solving, and the final results.
Example answer: "I led a migration project with legacy data issues, collaborating cross-functionally to resolve inconsistencies and deliver on time."

3.5.3 How do you handle unclear requirements or ambiguity?
How to answer: Emphasize your communication skills, iterative approach, and how you clarify objectives with stakeholders.
Example answer: "I schedule early check-ins, ask probing questions, and prototype solutions to align expectations."

3.5.4 Tell me about a time when your colleagues didn’t agree with your approach. What did you do to bring them into the conversation and address their concerns?
How to answer: Show your openness to feedback, collaborative spirit, and willingness to adapt.
Example answer: "I invited dissenting colleagues to a data review session and incorporated their ideas into the final solution."

3.5.5 Describe a time you had to negotiate scope creep when two departments kept adding “just one more” request. How did you keep the project on track?
How to answer: Discuss prioritization frameworks, transparent communication, and how you protected core deliverables.
Example answer: "I used MoSCoW prioritization, presented trade-offs, and secured leadership buy-in for scope control."

3.5.6 When leadership demanded a quicker deadline than you felt was realistic, what steps did you take to reset expectations while still showing progress?
How to answer: Highlight your ability to communicate constraints, propose phased delivery, and maintain transparency.
Example answer: "I broke the project into milestones and provided regular updates to demonstrate progress while negotiating for more time."

3.5.7 Tell me about a situation where you had to influence stakeholders without formal authority to adopt a data-driven recommendation.
How to answer: Focus on your persuasion techniques, evidence-based approach, and how you built consensus.
Example answer: "I built a compelling case with data prototypes and presented ROI estimates to gain stakeholder buy-in."

3.5.8 Describe a time you delivered critical insights even though 30% of the dataset had nulls. What analytical trade-offs did you make?
How to answer: Explain your treatment of missing data, validation of results, and clear communication of uncertainty.
Example answer: "I used multiple imputation and flagged unreliable segments, ensuring stakeholders understood the confidence intervals."

3.5.9 Give an example of automating recurrent data-quality checks so the same dirty-data crisis doesn’t happen again.
How to answer: Describe the automation tools or scripts you implemented, and the measurable impact on data reliability.
Example answer: "I built scheduled validation jobs that caught anomalies early, reducing manual cleaning time by 40%."

3.5.10 Tell me about a time you exceeded expectations during a project.
How to answer: Illustrate your initiative, resourcefulness, and the quantifiable results of your efforts.
Example answer: "I automated a manual reporting process, saving the team 10 hours per week and enabling faster decision-making."

4.1 Company-specific tips:

Get to know Reef’s business model and mission by exploring how the company leverages technology to transform urban spaces. Understand the challenges Reef addresses in last-mile delivery, logistics, and urban commerce, and be ready to discuss how software can enable efficiency and innovation in these contexts.

Review the types of industries Reef serves—such as food, retail, and mobility—and think about how software engineering solutions can support diverse operational needs. Be prepared to connect your technical skills to real-world problems faced by Reef’s clients and partners.

Research recent initiatives, partnerships, or product launches by Reef. Being able to reference current events or new features shows genuine interest and helps you tailor your responses to the company’s evolving priorities.

Familiarize yourself with the technology stack and platforms commonly used at Reef. If possible, review job postings or engineering blogs to identify preferred languages, frameworks, and cloud services, so you can highlight relevant experience in your interview.

4.2 Role-specific tips:

4.2.1 Master coding fundamentals and problem-solving for real business scenarios.
Focus your preparation on algorithms and data structures, especially those relevant to logistics, scheduling, and optimization. Practice breaking down complex problems into manageable components and explaining your approach clearly, as Reef values engineers who can tackle ambiguous challenges and communicate their reasoning.

4.2.2 Practice system design with scalability and modularity in mind.
Prepare for architecture questions by designing systems that handle high volumes of data, support multiple user roles, and are resilient to failure. Think about how you would build or improve digital infrastructure for urban logistics, and be ready to justify your design choices with trade-offs in scalability, security, and maintainability.

4.2.3 Demonstrate experience in cross-functional collaboration.
Reflect on past projects where you worked closely with product managers, designers, or stakeholders outside engineering. Be prepared to share examples of how you translated business requirements into technical solutions, and how you communicated technical decisions to non-technical audiences.

4.2.4 Show proficiency in writing clean, efficient, and maintainable code.
Highlight your ability to write code that is both performant and easy to maintain. Emphasize your approach to code reviews, testing, and documentation, as Reef seeks engineers who contribute to a culture of quality and continuous improvement.

4.2.5 Prepare to discuss data quality, cleaning, and validation.
Be ready to talk through your process for managing messy or incomplete data, especially in the context of logistics and real-time operations. Share examples of how you identified data issues, implemented cleaning strategies, and ensured reliability for downstream applications.

4.2.6 Practice communicating technical insights with clarity and adaptability.
Anticipate questions about presenting complex findings to different audiences. Develop concise explanations for technical concepts and be prepared to tailor your message to business stakeholders, emphasizing actionable recommendations and business impact.

4.2.7 Review behavioral examples that showcase adaptability and initiative.
Prepare stories that demonstrate your ability to thrive in dynamic, fast-paced environments. Think about times you exceeded expectations, handled setbacks, or influenced stakeholders without formal authority, as these qualities are highly valued at Reef.

4.2.8 Be ready to discuss trade-offs and decision-making in ambiguous situations.
Expect questions about handling unclear requirements, negotiating scope, or resetting expectations under pressure. Practice articulating your approach to prioritization, stakeholder communication, and iterative development, showing your ability to drive progress even when facing uncertainty.

5.1 How hard is the Reef Software Engineer interview?
The Reef Software Engineer interview is moderately challenging and designed to assess both your technical depth and real-world problem-solving abilities. You'll face questions that test your knowledge of algorithms, data structures, system architecture, and your ability to reason through business-driven scenarios. Reef values engineers who can build scalable solutions, communicate clearly, and adapt to ambiguity—so expect a mix of practical coding, system design, and behavioral questions that require thoughtful, well-structured responses.

5.2 How many interview rounds does Reef have for Software Engineer?
The typical process includes 4–6 rounds: an initial application and resume review, a recruiter screen, technical/case/skills interviews, a behavioral interview, and a final onsite or virtual round with multiple team members. Each stage is designed to evaluate specific aspects of your technical and collaborative skill set.

5.3 Does Reef ask for take-home assignments for Software Engineer?
While Reef’s process primarily focuses on live technical interviews and system design sessions, some candidates may be given a take-home assignment or coding exercise, especially if the team wants to further assess your coding style or approach to open-ended problems. These assignments are usually relevant to the types of challenges Reef engineers face in transforming urban logistics and commerce.

5.4 What skills are required for the Reef Software Engineer?
Reef looks for strong fundamentals in algorithms, data structures, and scalable system design. Proficiency in programming languages like Python, Java, or JavaScript is important, as is experience with distributed systems, cloud platforms, and collaborative development. You should also demonstrate skills in data cleaning, validation, and the ability to communicate technical insights to both technical and non-technical audiences.

5.5 How long does the Reef Software Engineer hiring process take?
The typical timeline is around 3–5 weeks from initial application to final offer. Fast-track candidates with highly relevant experience or strong referrals may complete the process in 2–3 weeks, while most candidates should expect about a week between each stage, depending on scheduling and team availability.

5.6 What types of questions are asked in the Reef Software Engineer interview?
Expect a blend of coding challenges, algorithmic problem-solving, system design exercises, and scenario-based questions tailored to real business contexts. You’ll also encounter behavioral questions focused on collaboration, adaptability, and communication. Reef interviewers are interested in how you approach ambiguous problems, design scalable solutions, and interact with cross-functional teams.

5.7 Does Reef give feedback after the Software Engineer interview?
Reef typically provides feedback through recruiters, especially if you progress to later stages. While detailed technical feedback may be limited, you will receive high-level insights into your performance and areas for improvement.

5.8 What is the acceptance rate for Reef Software Engineer applicants?
While Reef does not publicly disclose specific acceptance rates, the role is competitive, with an estimated 3–7% acceptance rate for qualified candidates. Success depends on demonstrating both technical excellence and alignment with Reef’s mission and culture.

5.9 Does Reef hire remote Software Engineer positions?
Yes, Reef offers remote opportunities for Software Engineers, with some roles requiring occasional in-person collaboration depending on project needs and team structure. The company supports flexible work arrangements to attract top engineering talent from diverse locations.

• Related guides:
  • Reef interview questions
  • Software Engineer interview guide
  • Top software engineering interview tips

Ready to Ace Your Interview?

Ready to ace your Reef Software Engineer interview? It’s not just about knowing the technical skills—you need to think like a Reef Software Engineer, solve problems under pressure, and connect your expertise to real business impact. That’s where Interview Query comes in with company-specific learning paths, mock interviews, and curated question banks tailored toward roles at Reef and similar companies.

With resources like the Reef Software Engineer Interview Guide and our latest case study practice sets, you’ll get access to real interview questions, detailed walkthroughs, and coaching support designed to boost both your technical skills and domain intuition.

Take the next step—explore more case study questions, try mock interviews, and browse targeted prep materials on Interview Query. Bookmark this guide or share it with peers prepping for similar roles. It could be the difference between applying and offering. You’ve got this!