How to Take Over an Existing Software Project Safely
Key takeaway
A safe takeover runs in four phases: secure access and ownership of code, cloud accounts, domains, and credentials; audit the code and infrastructure; transfer knowledge from the outgoing team while they are still available; and stabilise — tests, CI, monitoring, and backups — before changing features. For a typical product, that transition takes roughly two to six weeks.
Taking over software someone else built is common: a vendor relationship ends, an in-house team moves on, or a product outgrows the people who started it. Takeovers go wrong in predictable ways — access that lives in a former contractor's personal account, no documentation, an outgoing team that disappears before handover, or a new team that starts changing things before it understands them.
A structured takeover avoids those failures. The order matters more than the speed.
Phase 1: Secure access and ownership
- Source code repositories, with full history, under an account your company owns.
- Cloud, hosting, and database accounts — with your company as the owner, not just a user.
- Domains, DNS, SSL certificates, and email-sending services.
- App store accounts, signing keys, and certificates for mobile apps.
- Third-party services and API keys, including who pays for them.
- Contracts confirming you own the intellectual property in the code.
Phase 2: Audit the code and infrastructure
- Can the project be built and deployed from scratch, from the repository alone?
- Dependencies — outdated or unsupported frameworks, and known security vulnerabilities.
- Architecture — how the parts fit together and where the fragile areas are.
- Tests — what is covered, and whether the tests actually run.
- Infrastructure and running costs — what is deployed, what it costs, and what is unused.
- Security — secrets in code, access controls, and data protection.
Phase 3: Transfer knowledge while you still can
Arrange an overlap period with the outgoing team if at all possible, even a short one. Record walkthroughs of the architecture, the deployment process, and the areas people avoid touching. Capture open bugs, known workarounds, and anything "everyone knows" but nobody wrote down. Every question answered during the overlap is one you won't have to reverse-engineer later.
Phase 4: Stabilise before you change
- Set up continuous integration and a repeatable deployment, so releases stop depending on one person's laptop.
- Add monitoring and alerting, so you learn about problems before users report them.
- Confirm backups exist and test a restore.
- Write characterisation tests around critical behaviour before refactoring anything.
- Fix critical security issues found in the audit.
Then decide: maintain, refactor, or rebuild
Only with the audit and a stable baseline can you make a sound decision about the code's future. Most takeovers continue with the existing codebase and improve it incrementally; a rebuild is justified only when the audit shows the cost of change is consistently higher than replacing the part in question.
Warning signs to check early
- Nobody can deploy the current production version from the repository.
- Credentials or accounts are owned by individuals rather than the company.
- There are no backups, or restores have never been tested.
- The previous vendor's contract does not clearly transfer IP ownership.
How we run a takeover
We start with a fixed-scope assessment that works through the four phases above and ends in a written report: what we found, the risks in priority order, and a stabilisation plan. Feature work resumes once the project builds, deploys, and is monitored under your ownership — usually with the same dedicated team that ran the assessment, so nothing learned is lost.