ENGINEERING

Build a Feature 10x Faster with Cursor AI

Your manager says: 'Build a user authentication system with email/password, Google OAuth, and password reset. Normally takes 2 days for juniors, but I want you to use Cursor AI and finish in 4 hours. Show me how AI-assisted coding makes you 10x more productive. Document your process - I'm deciding whether to roll out Cursor to the whole team.'

What You'll Build:

• • Download Cursor:
• • Learn Cursor Commands:

Debug Code 5x Faster with Claude AI

Your senior engineer says: 'Production is down. We're getting 500 errors on the checkout flow. Debug and fix in <1 hour. Use Claude AI to help - upload error logs, stack traces, and suspicious code. I want to see how AI helps you debug faster than traditional trial-and-error.'

What You'll Build:

• • Upload Error + Code Context:
• • Claude's Analysis Process:

Refactor Legacy Code with AI (Technical Debt Sprint)

Your CTO says: 'We have 2000 lines of spaghetti code in checkout.js. No tests, no documentation, jQuery mixed with React. Refactor it to modern TypeScript + React in 1 day using AI. I'm evaluating whether AI can help us pay down technical debt faster.' This is your chance to show AI's power.

What You'll Build:

• • Mixed jQuery + React (Anti-pattern):
• • No TypeScript Types:

Array Reversal Without Built-ins

You're building a data processing pipeline that handles millions of user events. Implement array reversal without built-in methods. Think about space vs time complexity trade-offs.

What You'll Build:

• • Algorithm Design
• • Implementation

Find Duplicates Efficiently

Find duplicates in an unsorted array efficiently. Array manipulation efficiency directly impacts system performance at scale.

What You'll Build:

• • Algorithm Approaches
• • Implementation

Rotate Array Elements

Rotate array elements by k positions. Practice explaining your approach out loud as you would in an interview.

What You'll Build:

• • Algorithm Design
• • Implementation

Design GraphQL API for Mobile & Web Clients

Your REST API is causing performance issues. Mobile clients make 8-12 API requests to load a single feed screen, resulting in 3-second load times and poor user experience. Each client has different data needs, leading to over-fetching and under-fetching. You need a GraphQL API to optimize data fetching and improve client performance.

What You'll Build:

• • Schema Design
• • Performance Optimization

Longest Common Subsequence

You're optimizing a recommendation engine that needs to find patterns in user behavior sequences. Solve the longest common subsequence problem. Start with recursive solution, then optimize.

What You'll Build:

• • Problem Understanding
• • Recursive Approach

Optimal Coin Change Solution

Implement optimal solution for coin change problem. Identify overlapping subproblems clearly.

What You'll Build:

• • Problem Definition
• • Greedy vs DP

Maximum Subarray Sum

Design a solution for maximum subarray sum (Kadane's algorithm). Performance is critical for real-time systems.

What You'll Build:

• • Problem Understanding
• • Brute Force

Design Database Sharding Strategy

Your PostgreSQL database has hit 2TB and query performance is degrading. Read latency spiked from 50ms to 800ms during Black Friday. Your largest tables (orders, products, users) are becoming bottlenecks. You need a sharding strategy to scale horizontally while maintaining data consistency and query performance.

What You'll Build:

• • Sharding Key Selection
• • Shard Architecture

Decompose Monolith into Microservices

Your monolithic Rails application has grown to 500K lines of code with 40 engineers working on it. Deployment takes 45 minutes, any bug can take down the entire site, and teams are blocked waiting on each other. Database queries are timing out, and you're hitting 10K requests/second at peak. You need to decompose into microservices while maintaining business continuity.

What You'll Build:

• • Service Boundaries
• • Migration Strategy

Design Background Job Processing System

Your background job system is struggling. Report generation takes 2-3 hours (customers expect <15 minutes), export jobs are timing out, and failed jobs are silently disappearing. During peak hours, 30% of jobs fail and never retry. You need a robust background job system that can handle report generation, data exports, email sending, and API integrations reliably at scale.

What You'll Build:

• • Job Queue Architecture
• • Reliability & Retry Logic

Design Real-Time Notification System

Your notification system is cracking under pressure. Users are experiencing 5-10 second notification delays during peak hours, and engagement has dropped 15% as a result. You need a real-time push notification architecture that can handle 500K notifications/second with sub-second latency.

What You'll Build:

• • Architecture Design
• • Delivery Strategy

Implement Service Mesh for Microservices

Your microservices architecture is experiencing cascading failures. When the payment service slows down, it takes down the entire booking flow. You have no visibility into service-to-service communication, mTLS is inconsistent across services, and implementing circuit breakers requires code changes in every service. You need a service mesh to handle cross-cutting concerns without modifying application code.

What You'll Build:

• • Service Mesh Selection
• • Traffic Management

Design Message Queue System for Async Processing

Your synchronous payment processing is causing timeout issues. When fraud checks take 3+ seconds, API requests fail and customers abandon purchases. You're losing $2M/month to failed transactions. You need an async message queue system to handle fraud checks, webhook deliveries, reconciliation, and notification sending without blocking user-facing APIs.

What You'll Build:

• • Architecture Design
• • Reliability Guarantees

Design Event-Driven Architecture

Your monolithic order processing system is a bottleneck. When an order is placed, 12 different services need to react (inventory, shipping, analytics, fraud detection, CRM, etc.). Currently, your REST API chains these calls synchronously, causing 8-second order confirmation times and cascading failures when any downstream service is slow. Order processing fails 5% of the time during peak periods. You need an event-driven architecture to decouple these systems.

What You'll Build:

• • Architecture Design
• • Event Schema & Versioning

Design Data Pipeline Architecture

Your data team runs manual SQL scripts to move data between systems. Analytics dashboards are 24 hours behind. Data quality issues cause wrong reports. Engineers spend 40% of time on data plumbing instead of analysis. You need a reliable, scalable data pipeline that automates ingestion, transformation, and loading.

What You'll Build:

• • Pipeline Architecture
• • Technology Stack

Build Stream Processing System

Your real-time features (surge pricing, driver matching, live ETAs) run on batch jobs that refresh every 5 minutes. Surge pricing lags reality by 10 minutes, causing driver shortages and customer complaints. You need a stream processing system that processes events in real-time (<1 second) for pricing, matching, and analytics.

What You'll Build:

• • Streaming Architecture
• • Processing Framework

Design Data Lakehouse Architecture

You have separate data lake (S3 - cheap but slow) and data warehouse (Snowflake - fast but expensive). Data duplication costs $500K/year. ETL between lake and warehouse is complex. ML team wants data lake flexibility, analytics team wants warehouse performance. You need a lakehouse architecture that combines benefits of both.

What You'll Build:

• • Lakehouse Architecture
• • Technology Selection

Build Real-Time Analytics Platform

Your analytics are batch - dashboards update daily, A/B test results take 24 hours, anomaly detection is reactive. Product managers want real-time metrics to catch issues immediately. Competitors see problems within minutes and roll back. You need sub-second analytics on billions of events to power real-time dashboards, alerts, and decisions.

What You'll Build:

• • Architecture Design
• • Technology Selection

Implement Data Mesh Strategy

Your centralized data team (10 people) is a bottleneck for 20 product teams. Data requests take months. Each team builds shadow data pipelines in their services. Data quality is inconsistent. Your VP Engineering mandates data mesh - domain teams own their data products, data platform provides self-serve infrastructure. You need to architect and roll out data mesh.

What You'll Build:

• • Data Mesh Principles
• • Platform Architecture

Design Component State Management Architecture

Your state management is a mess. Props are being drilled through 5+ component layers, the same API data is fetched multiple times across components, and state updates are causing unnecessary re-renders. Your app is sluggish with 300ms lag on interactions, and developers spend hours debugging 'where is this state coming from?' You need a proper state management architecture.

What You'll Build:

• • State Architecture
• • Technology Choices

Implement WCAG 2.1 AA Accessibility Standards

Your platform is facing accessibility lawsuits. 15% of your users have disabilities (vision impairment, motor limitations, hearing loss), and they can't complete critical tasks like booking appointments or viewing lab results. Screen readers can't navigate your forms, keyboard users get trapped in modals, and color-blind users can't distinguish error states. You must achieve WCAG 2.1 AA compliance within 6 months.

What You'll Build:

• • Accessibility Audit
• • Technical Implementation

Optimize Frontend Build System Performance

Your build system is killing productivity. Production builds take 18 minutes, development hot reload takes 8 seconds, and CI pipelines run 35 minutes per PR. Engineers complain about slow feedback loops, and you're burning $5K/month on CI minutes. You need to optimize the build system to get builds under 5 minutes and dev server restarts under 2 seconds.

What You'll Build:

• • Build Tool Strategy
• • Monorepo Optimization

Design Micro-Frontend Architecture for Multiple Teams

Your monolithic React application has become a coordination nightmare. 8 teams are blocked on each other, every deploy requires full regression testing, and the build takes 25 minutes. Teams want autonomy to ship independently, use different frameworks, and deploy on their own schedule. You need a micro-frontend architecture to enable team independence while maintaining a cohesive user experience.

What You'll Build:

• • Architecture Pattern
• • Integration Strategy

Design Infrastructure as Code Strategy

Your infrastructure is managed manually through AWS console. Two engineers hold all the infrastructure knowledge, changes are undocumented, and you recently had a production outage because someone accidentally deleted an RDS database. Spinning up staging environments takes 2 days of manual clicking. You need Infrastructure as Code to make infrastructure reproducible, version-controlled, and safe to change.

What You'll Build:

• • IaC Tool Selection
• • Repository Structure

Design Modern CI/CD Pipeline

Your CI/CD pipeline is a bottleneck. Builds take 45 minutes, tests fail intermittently, and deploy queue gets backed up with 10+ PRs waiting. Engineers merge code on Friday and it doesn't deploy until Monday. You have zero rollback automation, and a bad deploy recently caused 2 hours of downtime. You need a fast, reliable CI/CD pipeline that enables continuous deployment with confidence.

What You'll Build:

• • Pipeline Architecture
• • Testing Strategy

Design Multi-Cluster Kubernetes Architecture

Your single-region Kubernetes cluster is causing issues. EU customers experience 300ms latency, regulatory requirements demand data residency, and a region outage would take down your entire platform. You're running 200+ microservices, and the cluster is hitting scalability limits with 5K nodes. You need a multi-cluster, multi-region Kubernetes architecture for scale, compliance, and reliability.

What You'll Build:

• • Cluster Topology
• • Service Discovery & Routing

Design Comprehensive Observability Stack

When production issues occur, your team is blind. It takes 2 hours to identify which service is causing problems, logs are scattered across services, and you have no distributed tracing. A recent outage cost $500K in lost transactions because you couldn't quickly identify the root cause. You need a comprehensive observability stack with metrics, logs, traces, and alerting.

What You'll Build:

• • Metrics Infrastructure
• • Logging Architecture

Design Enterprise Disaster Recovery Plan

Your platform has no formal disaster recovery plan. When AWS US-East-1 had a regional outage last month, your entire platform was down for 6 hours, costing $2M in SLA penalties and damaging customer trust. Hospitals couldn't access patient records during emergencies. You need an enterprise-grade DR plan with multi-region failover, backup strategies, and tested recovery procedures.

What You'll Build:

• • DR Architecture
• • Backup Strategy

Design API Rate Limiting System

Your API is getting hammered. Some developers are making 1000+ requests/second with poorly written scripts, causing latency spikes for everyone else. You're seeing 503 errors during peak hours, and paying customers are complaining about slow response times. You need a rate limiting system to protect your infrastructure and ensure fair usage.

What You'll Build:

• • Rate Limiting Algorithm
• • Implementation Design

Design Caching Strategy for High Traffic

Your homepage is hitting the database 2000 times per second, causing p95 latency of 1.2 seconds. During traffic spikes, your PostgreSQL connection pool maxes out and users see timeouts. Your most popular content pages are fetched from the database on every request despite changing only once per hour. You need a caching layer to reduce database load and improve response times.

What You'll Build:

• • Cache Layer Design
• • Cache Key Strategy

Optimize Frontend Performance for Core Web Vitals

Your Core Web Vitals are failing. LCP is 4.5s (needs <2.5s), FID is 250ms (needs <100ms), CLS is 0.35 (needs <0.1). Google is penalizing your SEO rankings, and analytics show 15% bounce rate on slow pages. Your conversion rate drops 20% for every extra second of load time. You need to optimize frontend performance to meet Web Vitals targets.

What You'll Build:

• • LCP Optimization
• • FID/INP Optimization

Design Mobile Push Notification System

Your push notification system is poorly implemented. Users complain about receiving notifications for actions they've already seen in-app, duplicate notifications arrive, and notification delivery is inconsistent (some users get them in 1 second, others in 5 minutes). Opt-in rate is only 40% because users are annoyed. You need a robust push notification system with smart delivery, deduplication, and personalization.

What You'll Build:

• • Push Infrastructure
• • Smart Delivery

Build Mobile Testing Strategy

Your mobile app has quality issues - 15% of releases have critical bugs, manual QA takes 3 days, regression bugs frequent, no automated tests. Last release: payment bug affected 50K users, $2M in customer credits. Your CTO mandates testing before another incident. You need comprehensive mobile testing strategy.

What You'll Build:

• • Testing Pyramid
• • iOS Testing

Design Offline-First Mobile Architecture

Your technicians work in areas with poor connectivity (basements, rural areas, construction sites) and frequently lose network access. Currently, the app becomes unusable offline, causing 30% of work orders to be delayed. Technicians complain about lost data when connectivity drops mid-task. You need an offline-first architecture that works seamlessly with or without network, syncing when connectivity returns.

What You'll Build:

• • Data Architecture
• • Sync Strategy

Implement Mobile App Security Hardening

Security researchers found vulnerabilities in your mobile app: API keys hardcoded in the binary, no certificate pinning (MITM attacks possible), user tokens stored in plain text, and the app works on jailbroken/rooted devices. You're at risk of API abuse, account takeovers, and data breaches. Banking regulators are demanding immediate security improvements. You need comprehensive mobile security hardening.

What You'll Build:

• • Data Protection
• • Network Security

Design iOS SwiftUI Architecture

Your iOS app is UIKit-based from 2018, but SwiftUI is now production-ready. Your team wants to migrate for modern declarative UI, better animations, and faster development. But your codebase has 200+ screens, complex state management, and deep UIKit integration. You need a SwiftUI architecture that works for complex apps, not just demos.

What You'll Build:

• • Architecture Pattern
• • State Management

Build Android Jetpack Compose App

Your Android app uses XML layouts and fragments from 2016. Development is slow - simple UI changes take days. Jetpack Compose promises 40% less code and faster iteration. Your team wants to migrate, but you have 300 screens and complex custom views. You need Compose architecture that handles production complexity.

What You'll Build:

• • Architecture Pattern
• • State Management

Optimize App Store Presence

Your organic app store growth is flat - 1K downloads/day while competitors get 10K+. Your app ranks #47 for 'workout tracker' (need top 10 for visibility). 3.2 star rating with reviews complaining about bugs. Paid UA costs $8/install and isn't scalable. You need app store optimization to drive organic growth and reduce CAC.

What You'll Build:

• • Keyword Optimization
• • Visual Assets

Design Mobile App Performance Monitoring

Your mobile app has performance issues but you lack visibility. App Store reviews complain about slow loading (3.2 star rating), 25% of sessions experience crashes, and checkout flow has a 40% drop-off. You don't know which devices are affected, what causes the slowness, or where crashes happen. You need comprehensive app performance monitoring to identify and fix issues proactively.

What You'll Build:

• • APM Tool Selection
• • Performance Metrics

Optimize Cross-Platform Performance

Your React Native app is slower than native competitors - 3s startup time (native apps <1s), janky scrolling (45fps vs. 60fps), high crash rate (2% vs. 0.5%). App Store reviews complain about performance. Your VP Product demands native-level performance or consider rewriting in native. You need to optimize React Native to competitive performance levels.

What You'll Build:

• • Startup Optimization
• • Rendering Performance

Design Cross-Platform Mobile Strategy

You're iOS-only and losing 50% of potential customers who use Android. Building a native Android app will take 12 months with a separate 8-engineer team. Meanwhile, React Native and Flutter promise cross-platform development with a single codebase. You need to decide: native iOS + Android, React Native, Flutter, or hybrid approach - with implications for team structure, tech debt, and time to market.

What You'll Build:

• • Technology Evaluation
• • Migration Strategy

Design Skill-Based Matchmaking System (SBMM)

You're a junior backend engineer. Your tech lead says: 'Our matchmaking system puts pro players against beginners. Players are rage-quitting. Design a skill-based matchmaking (SBMM) algorithm that creates fair matches in <10 seconds. Use AI to learn ranking systems (Elo, TrueSkill), then design our system.' This is critical - bad matchmaking = players quit.

What You'll Build:

• • Ranking Systems:
• • Matchmaking Algorithms:

Build Threat Modeling Framework

Your security team reviews features after they ship, finding critical vulnerabilities in production. Last quarter: 3 SQL injection bugs, 2 auth bypasses, 1 data leak - all preventable with threat modeling. Remediation cost $500K and 6 engineer-months. Your CISO mandates threat modeling for all new features before development. You need a lightweight framework that engineers will actually use.

What You'll Build:

• • Threat Modeling Process
• • STRIDE Framework Application

Build Secrets Management Strategy

Your secrets are everywhere - hardcoded API keys in code, .env files in repos, Slack messages with passwords, shared Google Docs with credentials. Last week: GitHub leaked AWS keys, $50K fraudulent charges. Your Series A investors require secrets management for due diligence. You need centralized, secure, auditable secrets management.

What You'll Build:

• • Secrets Management Platform
• • Application Integration

Build Privacy by Design Framework

Privacy incidents are costing you - last quarter had 5 privacy bugs in production (doctor accessed wrong patient, analytics leaked PII, search autocomplete exposed diagnoses). Each incident requires breach notification and damages trust. Your Chief Privacy Officer mandates privacy by design - build privacy in from the start, not retrofit after incidents. You need privacy engineering practices.

What You'll Build:

• • Privacy Principles
• • Design Patterns

Design Secure API Architecture

Your public API has security issues - no rate limiting (DDoS risk), weak auth (API keys in URLs), no input validation (injection attacks), verbose errors (info leakage). Last month: credential stuffing attack (10K requests/sec), data leak via error messages, $200K in bandwidth from DDoS. Enterprise customers demand SOC 2 compliance. You need to redesign API security.

What You'll Build:

• • Authentication & Authorization
• • Input Validation & Sanitization

Manage Cloud Security Posture

Your AWS environment is a security mess - S3 buckets publicly accessible, overly permissive IAM roles, unencrypted data, no logging. Last month: S3 bucket leak exposed 2M customer records. Auditors found 500 critical misconfigurations. Your VP Eng mandates security posture management to prevent future incidents. You need continuous monitoring and automated remediation.

What You'll Build:

• • Security Posture Assessment
• • Policy & Guardrails

Build Security Code Review Process

Security bugs slip through code review - last quarter had 15 security incidents from merged code (auth bugs, XSS, SQL injection). Your 3-person security team can't review 50 PRs/day. Engineers don't know what to look for. You need scalable security code review that catches issues before production without bottlenecking development.

What You'll Build:

• • Automated Security Scanning
• • Security-Focused Review Guidelines

Implement Zero Trust Architecture

Your security perimeter model failed - recent breach where attacker got VPN credentials and accessed all internal systems. Your network assumes 'inside = trusted.' Services call each other without auth. Employees have broad access. SOC 2 auditors flagged this. You need zero trust - never trust, always verify - for internal systems and customer data.

What You'll Build:

• • Zero Trust Principles
• • Identity & Access Management

Build Security Monitoring & SIEM

You're blind to security threats - no centralized logging, security team manually checks logs, incidents discovered weeks later. Last breach: compromised account active for 30 days before detection. SOC 2 auditors require security monitoring. You need SIEM (Security Information and Event Management) with real-time threat detection and automated response.

What You'll Build:

• • SIEM Architecture
• • Use Case Development

Implement GDPR Compliance

You're launching in Europe next quarter but not GDPR compliant - no data mapping, unclear data retention, hard to delete user data, no consent management. Non-compliance fines are 4% of revenue ($20M risk). Your legal team mandates GDPR compliance before EU launch. You need technical implementation of data rights, consent, and privacy controls.

What You'll Build:

• • Data Mapping & Inventory
• • Data Subject Rights

Create Incident Response Playbook

Last month's security incident was chaos - suspected breach detected at 9PM, no playbook, wrong people paged, 6 hours to contain, $2M in customer credits for downtime. Post-mortem revealed we didn't know who to call, what data was affected, or how to communicate. Your board mandates incident response program for next audit. You need playbooks, training, and tested procedures.

What You'll Build:

• • Incident Response Framework
• • Playbook Development

Build Customer Segmentation Model

Your marketing team sends same campaigns to all customers. Conversion is 2% (industry best practice 8%). High-value customers get generic offers, price-sensitive customers see premium messaging. You need customer segmentation to personalize marketing, pricing, and product recommendations. Segments must be actionable and drive measurable business impact.

What You'll Build:

• • Feature Engineering
• • Modeling Approach

Build Anomaly Detection System

Fraud costs you $5M/year. Manual review catches 60% of fraud but takes 24 hours. By then, fraudulent transactions are complete. Your rule-based system (>$1K transactions flagged) has 95% false positives. You need ML-based anomaly detection that catches fraud in real-time with <10% false positive rate while maintaining <100ms latency for transaction decisions.

What You'll Build:

• • Problem Formulation
• • Feature Engineering

Design Recommendation Engine

Your homepage shows generic trending songs. 60% of plays come from search (users know what they want), only 10% from recommendations. Spotify drives 40% plays through personalized playlists. You need a recommendation engine that personalizes for taste, context (workout vs. sleep), and discovery (new artists). Target: 10% → 30% plays from recommendations.

What You'll Build:

• • Recommendation Strategy
• • Modeling Techniques

Build Search Ranking Algorithm

Your search returns relevant jobs but ranking is poor. Machine learning engineer sees Java Developer jobs first, while recent grad sees senior roles. 40% of searches end without apply. Your competitor's search converts at 15%. You need learning-to-rank that personalizes results for user profile, intent, and behavior.

What You'll Build:

• • Ranking Problem Formulation
• • Feature Engineering

Design ML Model Deployment Strategy

Your ML models live in Jupyter notebooks. Deploying takes 2 weeks and multiple teams. Models drift undetected (performance degraded 30% over 6 months). No A/B testing or rollback capability. Data scientists can't iterate - blocked on engineering. Your VP Product mandates ML velocity - deploy models in days, not weeks, with safety and monitoring.

What You'll Build:

• • ML Platform Architecture
• • Deployment Pipeline