# Software Engineer I
**Role:** Software Engineer · **Level:** Band 30
**Company:** [American Express](https://scaleengineer.com/companies/american-express)
**Difficulty:** Medium
**Salary:** US$85000 - US$110000
**Experience:** 1 - 3
**Timeline:** ~14 days
The Software Engineer I (Band 30) interview at American Express is designed to assess foundational technical skills, problem-solving abilities, and cultural fit. Candidates are evaluated on their understanding of core computer science concepts, coding proficiency, and ability to collaborate effectively.
Canonical: https://scaleengineer.com/interviews/american-express/band-30-software-engineer
---
## Overall evaluation

- Technical Skills
- Behavioral and Cultural Fit
- Software Engineering Fundamentals

## Questions asked

- Write a function to reverse a linked list.
- Given an array of integers, find the two numbers that add up to a specific target.
- Explain the difference between a process and a thread.
- Describe a time you had to deal with a difficult stakeholder.
- How would you design a URL shortener?
- What are the principles of SOLID?
- Tell me about a project you are proud of.
- How do you handle code reviews?
- What is polymorphism?
- Describe your experience with version control systems like Git.

## Preparation tips

### lists

- Review fundamental data structures (arrays, linked lists, trees, graphs, hash maps) and algorithms (sorting, searching, recursion, dynamic programming).
- Practice coding problems on platforms like LeetCode, HackerRank, or similar.
- Understand object-oriented programming (OOP) principles.
- Brush up on your chosen programming language's core concepts.
- Prepare to discuss your past projects in detail, focusing on your contributions and the technologies used.
- Research American Express's mission, values, and recent news.
- Practice answering common behavioral questions using the STAR method.
- Prepare thoughtful questions to ask the interviewer.

### studyPlan

- {"title":"Data Structures and Complexity","longDescription":"Weeks 1-2: Focus on core data structures like arrays, linked lists, stacks, queues, trees (binary trees, BSTs), and hash maps. Practice implementing them and solving problems involving their usage. Understand time and space complexity analysis (Big O notation).","shortDescription":"Weeks 1-2: Data Structures (Arrays, Linked Lists, Trees, Hash Maps) & Complexity Analysis."}
- {"title":"Algorithms and Problem Solving","longDescription":"Weeks 3-4: Dive into algorithms such as sorting (bubble sort, merge sort, quicksort), searching (binary search), recursion, and basic graph traversal (BFS, DFS). Solve problems that require applying these algorithms.","shortDescription":"Weeks 3-4: Algorithms (Sorting, Searching, Recursion, Graph Traversal) & Problem Solving."}
- {"title":"Object-Oriented Programming","longDescription":"Week 5: Review Object-Oriented Programming (OOP) concepts (encapsulation, inheritance, polymorphism, abstraction) and design patterns. Practice coding problems that require OOP principles.","shortDescription":"Week 5: OOP Concepts and Design Patterns."}
- {"title":"Behavioral and Company Research","longDescription":"Week 6: Focus on behavioral preparation. Prepare stories for common behavioral questions using the STAR method. Research American Express and prepare questions to ask.","shortDescription":"Week 6: Behavioral Preparation & Company Research."}

## Location differences

- {"location":"New York","differences":{"tips":["Research American Express's values and recent projects.","Be prepared to discuss your resume in detail.","Practice explaining your thought process clearly.","Ask thoughtful questions about the role and the team."],"interviewFocus":["Understanding of core Java/Python/Node.js concepts.","Basic data structures and algorithms.","Problem-solving approach.","Communication skills.","Teamwork and collaboration."],"commonQuestions":["Tell me about a challenging project you worked on.","How do you handle conflicting priorities?","Describe a time you made a mistake and how you learned from it.","What are your strengths and weaknesses as a software engineer?","Why are you interested in American Express?"]}}
- {"location":"Chandler","differences":{"tips":["Highlight projects where you demonstrated initiative.","Showcase your ability to learn quickly.","Be genuine and enthusiastic.","Prepare questions about career growth opportunities."],"interviewFocus":["Adaptability and learning agility.","Understanding of software development lifecycle.","Ability to work independently.","Enthusiasm for technology.","Alignment with company values."],"commonQuestions":["Describe a situation where you had to adapt to a new technology.","How do you stay updated with industry trends?","What are your career goals?","Tell me about a time you received constructive feedback.","What do you know about our company culture?"]}}
- {"location":"Bangalore","differences":{"tips":["Use the STAR method (Situation, Task, Action, Result) for behavioral questions.","Emphasize your collaborative nature.","Demonstrate your passion for software engineering.","Ask about the team's collaboration tools and processes."],"interviewFocus":["Debugging and problem-solving skills.","Communication and interpersonal skills.","Motivation and drive.","Conflict resolution.","Understanding of team dynamics."],"commonQuestions":["How do you approach debugging a complex issue?","Describe a time you had to explain a technical concept to a non-technical audience.","What motivates you as a software engineer?","Tell me about a time you disagreed with a team member.","What are your expectations for this role?"]}}

## Round 1: Coding and Problem Solving
**Type:** Technical Interview (Coding) · **Difficulty:** Medium · **Duration:** 45 min
Live coding exercise focusing on data structures and algorithms.
This round typically involves a coding challenge, often presented as a live coding exercise or a take-home assignment. The interviewer will assess your ability to solve a given problem using code, focusing on your understanding of data structures, algorithms, and your coding proficiency. You'll be expected to explain your thought process, discuss potential edge cases, and optimize your solution.
**Interviewers look for:** A systematic approach to problem-solving.; Ability to translate a problem into code.; Understanding of fundamental algorithms and data structures.; Clear communication of their approach and reasoning.; Ability to identify and discuss trade-offs.
**Evaluation criteria:** Correctness of the solution; Efficiency of the solution (time and space complexity); Code clarity and readability; Problem-solving approach; Communication of thought process
**Common rejection reasons:** Inability to articulate thought process.; Incorrect or inefficient algorithm implementation.; Poor coding style or syntax errors.; Lack of understanding of basic data structures.
## Questions

- Given a string, find the first non-repeating character.
- Implement a function to check if a binary tree is a Binary Search Tree (BST).
- Find the kth smallest element in an unsorted array.

## Preparation tips

- Practice coding on a whiteboard or a simple text editor without IDE assistance.
- Think out loud and explain your approach before writing code.
- Consider edge cases and test your code mentally.
- Be prepared to discuss the time and space complexity of your solution.
- Ask clarifying questions if the problem statement is unclear.

## Round 2: Behavioral and Situational Assessment
**Type:** Behavioral Interview · **Difficulty:** Medium · **Duration:** 30 min
Assesses behavioral competencies, past experiences, and cultural fit.
This round focuses on your behavioral competencies and how you've handled various situations in the past. You'll be asked questions designed to understand your work style, how you collaborate with others, how you approach challenges, and your overall fit within the team and company culture. Use the STAR method (Situation, Task, Action, Result) to structure your answers.
**Interviewers look for:** Evidence of collaboration and teamwork.; Ability to handle challenges and learn from mistakes.; Clear communication and interpersonal skills.; Alignment with American Express's core values.; Genuine interest in the role and the company.
**Evaluation criteria:** Behavioral competencies (teamwork, communication, problem-solving); Past experiences and accomplishments; Motivation and career goals; Cultural fit and alignment with company values; Enthusiasm for the role and company
**Common rejection reasons:** Lack of clarity in explaining past experiences.; Inability to provide specific examples.; Appearing unenthusiastic or not a good cultural fit.; Not demonstrating alignment with company values.; Poor communication skills.
## Questions

- Tell me about a time you had to work with a difficult team member.
- Describe a project where you faced a significant technical challenge and how you overcame it.
- How do you prioritize your work when you have multiple competing deadlines?

## Preparation tips

- Prepare specific examples from your past experiences for common behavioral questions.
- Use the STAR method to structure your answers.
- Be honest and authentic in your responses.
- Show enthusiasm and passion for your work.
- Research American Express's values and culture beforehand.

## Round 3: System Design Fundamentals
**Type:** System Design Interview · **Difficulty:** Medium · **Duration:** 45 min
Assesses ability to design scalable and robust software systems.
This round evaluates your ability to design software systems. You'll be given a high-level problem (e.g., design a URL shortener, a social media feed, or a ride-sharing service) and asked to propose a solution. The focus is on your understanding of system components, scalability, data storage, APIs, and trade-offs. For a Band 30 role, the expectations might be more focused on understanding components and basic scaling rather than deep distributed systems knowledge.
**Interviewers look for:** A structured approach to designing complex systems.; Understanding of scalability, reliability, and performance.; Ability to identify and justify design choices.; Knowledge of common architectural patterns and technologies.; Ability to handle ambiguity and make reasonable assumptions.
**Evaluation criteria:** Understanding of system design principles; Ability to design scalable and reliable systems; Consideration of trade-offs; Knowledge of databases, caching, and distributed systems; Communication of design decisions
**Common rejection reasons:** Lack of understanding of system design principles.; Inability to scale solutions.; Poor trade-off analysis.; Not considering non-functional requirements.; Difficulty in communicating design choices.
## Questions

- Design a system to shorten URLs like TinyURL.
- How would you design a news feed for a social media platform?
- Design a rate limiter for an API.

## Preparation tips

- Study common system design concepts (load balancing, caching, databases, message queues).
- Practice designing common systems like Twitter feed, TinyURL, etc.
- Focus on breaking down the problem into smaller components.
- Discuss trade-offs for different design choices.
- Consider non-functional requirements like scalability, availability, and latency.