Claude Code
testing
Critical Business Logic Has No Test Coverage
Your test suite covers utility functions and simple CRUD operations but completely misses the critical business logic: payment processing, access control checks, data transformations, and state machine transitions. The parts of your code that are most likely to cause catastrophic failures if broken have zero test coverage.
Claude Code tends to generate tests for the easiest-to-test code (pure functions, simple helpers) while skipping the complex, stateful, integration-heavy code that actually needs testing the most. The coverage report may show 70% overall but the missing 30% contains all the high-risk logic.
This becomes painfully apparent when a 'small refactor' of the payment flow introduces a bug that charges customers the wrong amount, and no test catches it before production.
Error Messages You Might See
Payment charged wrong amount in production
User accessed admin panel without admin role
Data export missing records for edge case
State transition allowed that should be blocked
Common Causes
- Complex setup avoided — Tests for payment flows require Stripe test mode, database seeding, and multi-step setup that AI skips
- External service dependencies — Code that calls external APIs is left untested because mocking the API is complex
- State machine transitions untested — Status changes (pending -> processing -> completed -> failed) and their edge cases have no coverage
- Error handling paths untested — Only the happy path is tested; what happens on timeout, invalid input, or partial failure is unknown
- Coverage metrics misleading — Line coverage is high because simple code is tested, but branch coverage on critical paths is zero
How to Fix It
- Identify critical paths first — List your top 10 most important features (payment, auth, data export). These get tests first regardless of overall coverage
- Write integration tests for critical flows — Test the full flow from request to database, using test databases and service test modes (Stripe test keys)
- Test every state transition — For each status field, test every valid transition AND verify invalid transitions are rejected
- Test error handling explicitly — Force errors (network timeouts, invalid data, permission denied) and verify the app handles them gracefully
- Use branch coverage, not line coverage — Configure your coverage tool to report branch coverage. Aim for 100% branch coverage on critical paths
Real developers can help you.
Milan Surelia
Milan Surelia is a Mobile App Developer with 5+ years of experience crafting scalable, cross-platform apps at 7Span and Meticha. At 7Span, he engineers feature-rich Flutter apps with smooth performance and modern UI. As the Co-Founder of Meticha, he builds open-source tools and developer-focused products that solve real-world problems.
Expertise:
💡 Developing cross-platform apps using Flutter, Dart, and Jetpack Compose for Android, iOS, and Web.
🖋️ Sharing insights through technical writing, blogging, and open-source contributions.
🤝 Collaborating closely with designers, PMs, and developers to build seamless mobile experiences.
Notable Achievements:
🎯 Revamped the Vepaar app into Vepaar Store & CRM with a 2x performance boost and smoother UX.
🚀 Launched Compose101 — a Jetpack Compose starter kit to speed up Android development.
🌟 Open source contributions on Github & StackOverflow for Flutter & Dart
🎖️ Worked on improving app performance and user experience with smart solutions.
Milan is always happy to connect, work on new ideas, and explore the latest in technology.
Victor Denisov
Developer
Richard McSorley
Full-Stack Software Engineer with 8+ years building high-performance applications for enterprise clients. Shipped production systems at Walmart (4,000+ stores), Cigna (20M+ users), and Arkansas Blue Cross. 5 patents in retail/supply chain tech. Currently focused on AI integrations, automation tools, and TypeScript-first architectures.
Jacek Rozanski
Senior PHP/Symfony developer and DevOps engineer with 20+ years of professional experience, running opcode.pl (web development agency, est. 2004).
Day job: I'm the sole backend developer at merketing company where I own and maintain 11 PHP/Symfony microservices on AWS (ECS Fargate, RDS, S3, CloudFront), handle the full CI/CD pipeline (Bitbucket Pipelines, Docker), and manage monitoring with Sentry and CloudWatch. These services handle high request volumes in production every month.
What I bring to AI-built apps:
- I audit and fix security issues (OWASP methodology), performance bottlenecks, and architectural problems in codebases generated by Cursor, Claude Code, Lovable, Bolt, and v0
- I refactor AI-generated prototypes into production-grade applications with proper error handling, testing, and clean architecture (SOLID, DDD, hexagonal architecture)
- I set up the infrastructure AI tools don't touch: AWS hosting, CI/CD pipelines, automated deployments, database optimization, monitoring, and alerting
- I integrate external services: payment providers, email systems, partner APIs, SSO/auth
Tech stack: PHP 8.x, Symfony, React, Next.js, PostgreSQL, MySQL, Docker, AWS (ECS, RDS, S3, SQS/SNS, CloudFront), Terraform, Supabase. I also use AI tools daily (Claude Code, Cursor) in my own workflow, so I understand both the strengths and the gaps in AI-generated code.
Based in Poland (CET timezone). Available for async work and calls during EU/US business hours.
Taufan
I’m a product-focused engineer and tech leader who builds scalable systems and turns ideas into production-ready platforms.
Over the past years, I’ve worked across startups and fast-moving teams, leading backend architecture, improving system reliability, and shipping products used by thousands of users. My strength is not just writing code — but connecting product vision, technical execution, and business impact.
rayush33
JavaScript (React.js, React Native, Node.js) Developer with demonstrated industry experience of 4+ years, actively looking for opportunities to hone my skills as well as help small-scale business owners with solutions to technical problems
Vlad Temian
15+ years shipping production infrastructure for startups. Former CTO at qed.builders (acquired by The Sandbox).
Cursor ambassador and agentic tooling builder.
I've scaled systems, automated deployments, and built observability tools for AI coding workflows. I specialize in taking vibe-coded apps from broken prototype to production-ready: fixing Supabase auth/RLS, Stripe integrations, deployment pipelines, and cleaning up AI-generated spaghetti.
I build tools in this space (agentprobe, claudebin, micode) and understand both sides: how AI generates code and why it breaks.
https://blog.vtemian.com/
Kingsley Omage
Fullstack software engineer passionate about AI Agents, blockchain, LLMs.
Matthew Butler
Systems Development Engineer @ Amazon Web Services
Bastien Labelle
Full stack dev w/ 20+ years of experience
You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.
Get HelpFrequently Asked Questions
What should I test first when coverage is low?
Prioritize by risk: payment processing, authentication and authorization, data mutations that can't be undone, and any code that handles money or personal data. These are the paths where bugs cause the most damage.
How do I test code that calls external APIs?
Use the service's test mode (Stripe test keys, SendGrid sandbox) for integration tests. Use recorded HTTP responses (nock, VCR, responses) for unit tests. Test both success and error responses from the API.