10 - Project Evolution and Maintenance

Project Evolution: Scalability and Maintenance

A project doesn't end with deployment. The real challenge is maintaining, evolving, and scaling it over time. Claude can be a valuable partner for refactoring, adding features, and scalability decisions.

In this article, we'll see how to use Claude for continuous maintenance, guided refactoring, and planning project evolution.

Guided Refactoring with Claude

Claude excels at refactoring because it can analyze the complete context and suggest improvements while maintaining compatibility.

<role>You are a Senior Developer specialized in refactoring</role>

<context>
I have this OrderService that has grown too large.
It has 500+ lines and handles: CRUD, validation, notifications, payments.
</context>

<code>
[Paste the service code]
</code>

<task>
Analyze the service and propose a refactoring plan:
1. Identify Single Responsibility violations
2. Propose separation into smaller services
3. Suggest refactoring order (minimum risk)
4. Provide code examples for critical parts
</task>

<constraints>
- Maintain external API compatibility
- Incremental refactoring (no big bang)
- Each step must be deployable
</constraints>

Common Refactoring Patterns

Adding New Features

Feature Toggle Pattern

// FeatureToggleService.java
@Service
public class FeatureToggleService {{ '{' }}

    @Value("${{ '{' }}features.recurring-orders.enabled:false{{ '}' }}")
    private boolean recurringOrdersEnabled;

    @Value("${{ '{' }}features.recurring-orders.rollout-percentage:0{{ '}' }}")
    private int rolloutPercentage;

    public boolean isRecurringOrdersEnabled(String customerId) {{ '{' }}
        if (!recurringOrdersEnabled) return false;

        // Gradual rollout based on customer ID hash
        int hash = Math.abs(customerId.hashCode() % 100);
        return hash < rolloutPercentage;
    {{ '}' }}
{{ '}' }}

Technical Debt Management

# Tech Debt Backlog

## Critical
| Issue | Effort | Impact | Sprint |
|-------|--------|--------|--------|
| Spring Boot 3.0 → 3.2 (CVE) | 4h | Security | Next |
| N+1 query in OrderList | 2h | Performance | Next |

## High
| Issue | Effort | Impact | Sprint |
|-------|--------|--------|--------|
| OrderService split | 8h | Maintainability | Q2 |
| Add integration tests | 16h | Reliability | Q2 |

## Medium
| Issue | Effort | Impact | Sprint |
|-------|--------|--------|--------|
| Refactor DTOs to records | 4h | Code quality | Backlog |

Scalability

When to Scale

Preventive Maintenance

# Monthly Maintenance Checklist

## Dependencies
- [ ] Check vulnerabilities
- [ ] Update minor versions
- [ ] Review breaking changes

## Database
- [ ] Analyze slow queries
- [ ] Check table sizes
- [ ] Test backup restore

## Monitoring
- [ ] Review triggered alerts
- [ ] Analyze metric trends
- [ ] Check error logs

## Security
- [ ] Rotate secrets/keys
- [ ] Review access logs
- [ ] Check certificate expiry

Recap and Next Step

We've come a long way in the "Claude: AI-Driven Personal Project" series. In these articles, we've explored how to use Claude as a technical partner for every development phase:

In the next article, we'll see how to apply all of this in a real project: integrating Claude Code into Play The Event, a multi-stack project with DDD and Hexagonal architecture.