Building a secure, reliable, and highly available web application requires much more than writing clean code. The server side of your application must be legally compliant, resilient under pressure, recoverable, scalable, and secure. A well-designed backend ensures uninterrupted service, protects user data, and supports long-term growth.
This Server-Side Checklist covers all critical areas you should validate before deploying or scaling your web application.
1. Legal Compliance
Before going live, verify that your backend architecture and external dependencies do not introduce legal risks.
Key checks
- Third-party dependency licenses are not violated
- Ensure compliance with MIT, Apache, GPL, or any proprietary licenses used.
- Cryptography usage does not violate any applicable laws
- Some countries impose restrictions on strong encryption.
- Application follows organisational and industry standards
- For example, ISO, PCI-DSS, GDPR, HIPAA, or internal enterprise policies.
2. Resiliency
A resilient system remains functional even when components fail or when resources are constrained.
Key checks
- The application maintains reasonable functionality in isolation.
- It can recover from heavy load without manual intervention.
- Lost connections (DB, cache, message brokers) can be automatically reestablished.
- Application design prevents cascading failures, ensuring one failure does not bring down the whole system.
3. Load Balancing & Scalability
Your server must support horizontal scaling and operate smoothly behind load balancers.
Key checks
- Application can run efficiently on multiple CPUs.
- It supports running behind load balancers.
- New nodes can be added without downtime.
4. Transparent Deployment
Zero-downtime deployment is essential for modern applications.
Key checks
- New instances can be added without stopping the app.
- User sessions remain intact when nodes are added or removed.
- Rolling upgrades can be performed without disrupting service.
5. Supervising & Process Management
Unexpected crashes should not take your application offline.
Key checks
- The application survives a server restart.
- A supervisor (systemd, PM2, Docker restart policies, Kubernetes) automatically restarts crashed processes.
6. Logging Strategy
Logs are the backbone of debugging and auditing.
Key checks
- All errors—including swallowed or unhandled errors—are logged.
- Logs are written to rotated files to prevent disk overflows.
- Different log levels (info, warn, error) are separated.
- Logs are aggregated centrally (e.g., Elastic, Loki, Splunk).
7. Monitoring & Alerting
Early detection prevents outages.
Alerts configured for:
- Abnormal activity
- Application restart events
- High error rate
- Server resource exhaustion (CPU, memory, IO > 90%)
- HTTP request timeouts
- 5xx response spikes
Health checks cover all critical components, including:
- Databases
- Caches
- External APIs
- Message queues
8. Metrics & Observability
Make sure the application exposes measurable insights.
Key checks
- Track number of requests per endpoint.
- Track request duration and latency.
- Track business logic timings (e.g., job processing time).
This allows identifying slow endpoints, bottlenecks, and performance regressions.
9. High Availability
Your service should stay online even if a data center becomes unavailable.
Key checks
- Application supports deployment across multiple independent data centers or zones.
- Redundant systems are in place for failover and recovery.
10. Testing Under Realistic Conditions
Testing ensures your app behaves predictably under demand or failure.
Key checks
- Stress testing (load spikes, high concurrency).
- Network partitioning tests to simulate partial outages or latency spikes.
11. Backup and Recovery
Backups are useless if you cannot restore them.
Key checks
- All critical data can be restored from backups.
- Restore procedures are tested and verified.
12. Security
Security is a continuous process. Start by eliminating the most common vulnerabilities.
Key checks
- System is audited against OWASP Top 10 threats.
- TLS is enabled for all endpoints (no plain HTTP).
- Security headers are added:
- `X-Frame-Options`
- `X-Content-Type-Options`
- `Content-Security-Policy`
- `X-XSS-Protection`
- `Strict-Transport-Security`
- `Public-Key-Pins` (deprecated but still used in some legacy setups)
Conclusion
A well-secured, resilient, and properly monitored server-side architecture is the foundation of a reliable web application. Following this comprehensive checklist helps ensure your system is robust, scalable, and compliant with modern industry standards.
