Developer Assessments for the AI Era

Move beyond algorithmic puzzles and assess real engineering skills with challenges that mirror actual production environments.

The End of Traditional Interviews

AI Agents Excel at Basic Tasks

Modern AI coding agents solve basic algorithmic problems with near-perfect accuracy.

Wasted Interview Time

Time spent on tasks that AI agents can solve is time not spent evaluating real engineering skills.

The Start of Interviewing with AI in Mind

AI Collaboration Skills

Evaluate how effectively developers can work with AI coding assistants.

Real Production Scenarios

Our challenges mirror actual production environments, not isolated algorithmic puzzles.

What is VertexCode?

Engineering Assessment Platform

A modern platform for evaluating engineering talent through real-world challenges that test the skills that matter.

Built for the AI Era

Focused on assessing the engineering skills that remain uniquely human in an AI-driven world.

Real-World Challenges

Curated challenges based on actual production scenarios, testing system design and engineering skills.

Key Features

  • Challenges designed for LLM-assisted development
  • Real-world production scenarios and challenges
  • Multi-repository and legacy code tasks

Assessment Focus

  • System design and architecture
  • Trade-off analysis and decision making
  • Production environment awareness

Real-World Coding and Engineering Challenges

In the age of AI, we focus on both coding and engineering challenges that test real-world skills. While AI excels at basic coding tasks, true engineering requires human expertise in system design, trade-offs, and real-world constraints.

Coding

  • Writing instructions for computers
  • Implementing algorithms and data structures
  • Solving well-defined problems
  • Creating individual components
  • Following specifications

AI Strength: Modern AI coding agents excel at these tasks, often outperforming humans in speed and accuracy.

Engineering

  • Ensuring reliability and maintainability
  • Coordinating across teams and systems
  • Managing live production systems and rapid changes
  • Setting up and managing A/B testing frameworks
  • Handling versioning across multiple integrated systems

Human Strength: These aspects require deep understanding of business context, production realities, system design principles, and the ability to make rapid, safe changes in live environments.

"Our challenges focus on engineering skills that AI cannot yet master, ensuring we assess the human expertise that remains essential in modern software development."

Features for Everyone

LLM-Assisted Development

Challenges designed to be solved with modern AI coding assistants.

Real-World Scenarios

Practical challenges based on actual production environments.

Example Solutions

Learn from multiple approaches to each challenge.

For Companies

1

Select Challenge

Choose from our curated library of real-world engineering challenges.

  • Challenges available in multiple languages and frameworks
  • Choose based on your team's tech stack
  • Multiple difficulty levels for each challenge
2

Share Challenge

Share the challenge with candidates and provide necessary context.

  • Set custom time limits for each challenge
  • Allow candidates to use their preferred LLM
  • Provide additional context and requirements
3

Review & Evaluate

Review the candidate's solution and evaluate their engineering approach.

For Self-Learning

1

Choose Challenge

Select a challenge that matches your skill level and interests.

2

Solve Challenge

Work on the challenge in your preferred environment with LLM assistance.

3

Review Solutions

Compare your solution with example solutions and learn from different approaches.

Explore Our Challenge Library

Choose from a diverse range of challenges across multiple technologies and skill levels, designed to test real-world engineering skills.

Python
Java
React
Android
iOS

AI-Generated PR Review

45 min
ReactTypeScriptGit

Problem Statement

A PR was submitted by a coding agent, attempting to add a new view of the shopping cart. Review the PR provided, identify what parts of it we need to resolve and submit a new PR resolving the issues. This challenge tests your ability to review code, identify issues, and provide constructive improvements.

1

Review the provided PR and identify potential issues

2

Document the issues found and their impact

3

Propose solutions for each identified issue

4

Submit a new PR with the improvements

5

Include clear documentation of changes made

System Architecture

  • React frontend application
  • TypeScript for type safety
  • Git version control
  • Component-based architecture
  • State management system
  • Testing framework

Expected Outcomes by Experience Level

Junior Engineer

Identifies basic issues and provides straightforward fixes

  • Fixes syntax errors and type issues
  • Resolves compilation errors and missing dependencies
  • Improves basic code organization
  • Adds missing error handling
  • Updates documentation
  • Follows basic PR guidelines
  • Adds basic unit tests for new functionality
  • Ensures existing tests pass after changes

Senior Engineer

Identifies architectural concerns and provides comprehensive improvements

  • Improves component architecture
  • Identifies and removes non-allowed or deprecated libraries
  • Fixes incorrect class imports and circular dependencies
  • Analyzes and fixes performance degradation introduced by the PR
  • Implements effective logging for production support and debugging

Skills Assessed

Code Review

Identifying issues and suggesting improvements

Problem Solving

Proposing effective solutions to identified issues

Documentation

Clear communication of changes and rationale

Git Workflow

Understanding and following proper PR practices

Tax-Inclusive Pricing PR Review

45 min
ReactTypeScriptJavaAPI Design

Problem Statement

The product team wants to run a test where prices are displayed as tax-inclusive amounts. A coding agent was assigned to implement this change and has submitted a pull request. Review the PR and submit a subsequent PR with any further fixes. This challenge tests your ability to review code changes, ensure backward compatibility, and maintain system stability.

1

Review the provided PR for tax-inclusive pricing changes

2

Identify potential issues and edge cases

3

Ensure backward compatibility with existing clients

4

Implement proper test coverage

5

Submit a new PR with improvements and fixes

System Architecture

  • React frontend application
  • Java backend services
  • REST API endpoints
  • Database layer for price storage
  • Tax calculation service
  • Feature flag system
  • Testing framework

Expected Outcomes by Experience Level

Junior Engineer

Ensures basic functionality and stability

  • Verifies application compiles and runs
  • Ensures existing functionality works as expected
  • Adds basic unit tests for new functionality
  • Fixes obvious bugs and issues
  • Updates documentation
  • Follows basic PR guidelines

Senior Engineer

Ensures comprehensive system stability and proper implementation

  • Validates test structure and feature flag implementation
  • Ensures backward compatibility with existing API clients
  • Implements data-driven feature toggle mechanism
  • Adds comprehensive test coverage for pre-tax and post-tax scenarios
  • Reviews and improves error handling
  • Ensures proper logging and monitoring
  • Proposes architectural improvements

Skills Assessed

Code Review

Identifying issues and suggesting improvements

Backward Compatibility

Ensuring changes don't break existing functionality

Testing Strategy

Implementing comprehensive test coverage

Feature Flags

Managing feature rollout and testing

Shopping Cart Total Miscalculation

2 hr
ReactJava

Problem Statement

A customer reports their cart total is incorrect. Your task is to diagnose and fix the issue in a production system with multiple interconnected services. The complexity of your solution will demonstrate your level of experience and understanding of distributed systems.

1

Diagnose the issue across a multi-layered system

2

Identify the root cause in a complex codebase

3

Submit a PR with the fix and proper documentation

System Architecture

  • Frontend cart management
  • Backend pricing service
  • Discount calculation engine
  • Tax calculation service
  • Database layer
  • Caching system

Expected Outcomes by Experience Level

Junior Engineer

Identifies and fixes the immediate calculation issue

  • Fixes the calculation logic in the pricing service
  • Adds basic error handling
  • Updates the affected unit tests
  • Documents the fix in the PR
  • Verifies the fix in a test environment

Senior Engineer

Identifies systemic issues and implements comprehensive improvements

  • Implements proper error handling across services
  • Adds monitoring and alerting for calculation issues
  • Improves the testing strategy with integration tests
  • Proposes architectural improvements to prevent similar issues
  • Designs and implements a dedicated calculation engine for centralized logic
  • Adds comprehensive logging for easier future diagnostics
  • Implements automated validation checks for calculation results

Skills Assessed

Debugging

Systematic problem diagnosis and resolution

System Analysis

Understanding complex system interactions

Documentation

Clear communication of technical solutions

Problem Solving

Effective solution design and implementation

Mobile App Performance Optimization

45 min
AndroidPython

Problem Statement

Users are reporting slow app performance and high battery drain. The app is aggressively caching all data locally to reduce API calls, but this is causing memory issues and slow initial load times. Your solution will demonstrate your understanding of mobile performance optimization at different levels of sophistication.

1

Profile the app's memory usage to identify cache-related bottlenecks

2

Analyze the current caching strategy and its impact on performance

3

Implement a lazy loading solution for non-critical data

4

Document the changes and their impact on performance

System Architecture

  • React Native mobile application
  • Local SQLite database for caching
  • Redux state management with persistence
  • Image caching system
  • Offline data synchronization

Expected Outcomes by Experience Level

Junior Engineer

Implements basic lazy loading solution

  • Identifies obvious caching issues
  • Recognizes expensive polling patterns (e.g., 10ms intervals)
  • Works with coding agent to implement performance improvements
  • Implements simple lazy loading for images
  • Adds basic memory monitoring
  • Documents the changes made
  • Tests the solution in a development environment

Senior Engineer

Designs focused mobile performance optimization strategy

  • Identifies key mobile performance KPIs (battery, data usage, response time)
  • Proposes caching strategy considering battery impact
  • Recommends data freshness policy to replace aggressive polling
  • Suggests network-aware synchronization improvements
  • Outlines A/B testing approach with rollback strategy for performance improvements

Skills Assessed

Performance Analysis

Identifying and resolving basic performance bottlenecks

Data Management

Understanding when to cache vs. lazy load data

Mobile Development

Basic understanding of mobile app constraints

Documentation

Clear communication of technical solutions

Technical Excellence Assessment

1 hr
PythonJavaReact

Problem Statement

You've been given access to a codebase that needs improvement. Your task is to identify key areas where technical excellence can be enhanced. The codebase contains issues that can be addressed at different levels of sophistication, allowing us to assess your experience and depth of understanding.

1

Review the codebase and identify areas for improvement

2

Document specific technical excellence recommendations

3

Provide clear rationale for each recommendation

4

Include examples of current code and suggested improvements

5

Submit a well-structured .txt file with your analysis

System Architecture

  • Monolithic application structure
  • Basic error handling
  • Minimal logging
  • Direct database queries
  • No automated testing
  • Limited documentation
  • Basic security measures
  • Manual deployment process

Expected Outcomes by Experience Level

Junior Engineer

Identifies basic code quality issues and suggests straightforward improvements

  • Adding input validation
  • Improving error messages
  • Adding basic logging
  • Writing unit tests
  • Adding code comments

Senior Engineer

Identifies architectural concerns and suggests comprehensive improvements

  • Implementing proper error handling strategy
  • Introducing automated testing pipeline
  • Proposing security improvements
  • Suggesting CI/CD implementation
  • Identifying and removing inefficient polling mechanisms
  • Defining key production KPIs (memory usage, response times, error rates)
  • Addressing autoscaling concerns and resource optimization

Skills Assessed

Code Quality

Identifying and articulating code quality improvements

Technical Debt

Recognizing and addressing technical debt

Best Practices

Understanding and applying software engineering best practices

Documentation

Clear communication of technical recommendations

Production System Management

1 hr
ReactTypeScriptJavaAWSKubernetes

Problem Statement

You need to implement a critical security fix across multiple integrated systems in production. The fix requires coordinated changes across frontend, backend, and database layers. Your solution will demonstrate your ability to manage production systems, implement rapid changes safely, and handle versioning across multiple services.

1

Analyze the security vulnerability and its impact across systems

2

Design a coordinated fix that maintains system stability

3

Plan the deployment strategy with proper versioning

4

Set up A/B testing to validate the fix

5

Document the changes and create a rollback plan

System Architecture

  • React frontend application
  • Java backend services
  • AWS infrastructure
  • Kubernetes orchestration
  • Database layer
  • Feature flag system
  • A/B testing framework
  • Monitoring and alerting

Expected Outcomes by Experience Level

Junior Engineer

Implements basic production fixes with guidance

  • Identifies affected components in the system
  • Implements basic versioning for the fix
  • Follows established deployment procedures
  • Documents the changes made
  • Tests the fix in a staging environment

Senior Engineer

Designs comprehensive production change management strategy

  • Coordinates changes across multiple system boundaries
  • Designs A/B testing strategy to validate the fix
  • Implements proper versioning across all affected services
  • Sets up monitoring to track the fix's impact
  • Creates comprehensive rollback procedures
  • Establishes key metrics for success validation
  • Documents the incident response and prevention strategy

Skills Assessed

Production Management

Managing and coordinating changes in production systems

Version Control

Handling versioning across multiple integrated systems

A/B Testing

Setting up and managing A/B tests in production

Risk Management

Assessing and mitigating risks in production changes

Example 1 of 6

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