A practical checklist for taking over an inherited codebase

PoliteTech Editorial · Architecture and Modernization

1. Secure access and ownership

• Source code repositories, with full history.
• Cloud accounts, domains, DNS and SSL certificates.
• App store and Google Play developer accounts.
• Third-party services: email, payments, maps, analytics, error tracking.
• Confirm that these accounts belong to your organisation, not to a former vendor or individual.

2. Make it run

A new team should be able to build and run the application locally and deploy it to a test environment. If that is not possible from the documentation, writing those steps down is the first deliverable. It quickly reveals missing environment variables, hard-coded secrets and undocumented services.

3. Review the technical health

• Framework and dependency versions, and any that are no longer supported.
• Known security vulnerabilities in dependencies.
• Test coverage of the most important user journeys.
• Database structure, backups and restore procedures.
• Logging, monitoring and error tracking in production.

4. Understand the product, not just the code

Talk to the people who use the software and the people who support it. Which features matter most? Which bugs keep coming back? Which workarounds exist? Code review alone cannot answer these questions, and they decide what to fix first.

5. Stabilise before you build

Resist the urge to add features in the first weeks. Fix critical security issues, set up monitoring, automate the release process and add tests around fragile areas. This makes every later change safer and faster.

6. Agree a working rhythm

• A prioritised backlog that combines fixes, upgrades and improvements.
• Severity levels and response expectations for production issues.
• A regular release schedule with clear testing steps.
• A short monthly report on system health and progress.

The result

After this process you have control of your assets, a written picture of the system, a list of risks in priority order and a team that can change the software with confidence. That is a solid foundation for maintenance, modernisation or new development.