Taking over a legacy Laravel application starts by proving which source is running, where it runs, and how it is released. Then the new team builds a safety net before upgrading dependencies or redesigning modules. “Legacy” does not mean bad; the system may reliably carry important work. It means version, dependency, test, and operational knowledge needs evidence.
This is a deep Laravel technical checklist. It is deliberately distinct from the software vendor takeover guide, which covers contracts, accounts, continuity, and supplier exit for any technology. Complete the organizational transition, then perform this repository and environment audit.
Prove the production revision
Identify repository, branch, commit or tag, build artifact, and deployment path behind production. Compare lock files and build configuration. Do not assume the default branch matches a server that may contain manual edits or uncommitted built assets.
Record PHP, Laravel, web server, extensions, database, Redis, worker manager, Node, and SSR versions through read-only inspection. Differences become migration risks resolved through Git and controlled deployment, never by copying source files onto production.
Reproduce a clean environment
Begin from a fresh clone and an example environment without secrets. Document required services, extensions, build tools, and synthetic seed data. Never download production data to a developer machine for convenience.
Run installation, build, and tests from zero. If the process requires a personal key or undocumented file, register that dependency and replace it. A second engineer should be able to follow the same instructions.
Read Composer constraints and the lock
Identify Laravel, PHP, direct packages, abandoned packages, private repositories, and constraints preventing upgrade. Do not begin with an unrestricted update. Use Composer’s diagnostic commands to understand why a version is installed and what blocks a target.
Review scripts and plugins before granting execution. Preserve the lock file and upgrade one package or related group in a tested branch. Use the official Laravel upgrade guide for each framework jump.
Establish test baseline
Run Pest or PHPUnit, static analysis, formatting checks, frontend type checks, and build with documented commands. Separate existing failures from regressions introduced by the takeover. Do not make tests green by weakening assertions before understanding expected behavior.
When coverage is sparse, add characterization tests around authentication, authorization, a critical financial or operational journey, one job, and one integration. These capture existing behavior without claiming its architecture is ideal.
Trace a request end to end
Follow routes through middleware, Form Requests, policies, controllers, services, models, events, and jobs. Look for business rules hidden in views, observers, accessors, or frontend code. Record coupling before moving it.
Test CSRF, sessions, rate limiting, exception rendering, and server-side authorization. Identify debug or experimental routes. An administrative link hidden from navigation remains an exposed endpoint if its policy is missing.
Compare migrations with the real schema
Inspect production schema safely and compare it with migrations. Long-lived systems can contain indexes, tables, or types that history no longer reproduces. Do not rerun old migrations on production to “fix” the mismatch.
Review foreign keys, indexes, nullable values, statuses, timezones, and destructive cascades. Establish a baseline or planned corrective migration after evidence. Test backup restoration before any structural change.
Review models and authorization
Inspect fillable or guarded settings, casts, hidden attributes, relationships, scopes, and soft deletion. Mass-assignment protection is not authorization. Domain operations need policy or service checks against actor, record, and state.
Attempt IDOR by changing route and file identifiers, especially nested and export endpoints. For SaaS, use the Laravel tenant isolation testing guide to cover jobs, files, caches, and integrations beyond a tenant_id.
Inventory queues and schedules
Record connections, queue names, workers, timeouts, attempts, backoff, failed jobs, batches, and Horizon configuration. Identify non-idempotent jobs that can repeat a payment, allocation, or notification after retry. Test failure after an external side effect but before local acknowledgement.
Review cron, Scheduler timezone, overlap prevention, and single-server locks. A daily task can silently stop for months. Monitor queue age, failures, and schedule execution rather than merely checking that a worker process exists.
Understand cache and sessions
Identify stores, prefixes, TTLs, and whether tenant or user identity appears in keys. Find forever caches and broad flush operations. Do not run routine cache flushes against a Redis database that also stores authenticated sessions.
Review cookie domain, secure and SameSite settings, session rotation, and lifetime. Never rotate APP_KEY casually; encrypted values and sessions can become unreadable. Document key custody and recovery.
Audit storage, mail, and integrations
List disks, visibility, signed links, temporary files, media processing, mail transports, and notification queues. Try unauthorized file downloads. Ensure test environments cannot send to real recipients.
For every external API, record authentication, timeout, retry, idempotency, signature validation, sandbox, and owner. The reliable webhook receiver guide should inform any financial or state-changing callback.
Inspect secrets and logs
Search for secrets in source, artifacts, and logs without printing them into reports. If one leaked, rotate it and repair custody; deleting the latest line does not remove Git history. Move values to approved server configuration or secret management.
Review request, exception, and job logging for passwords, tokens, and sensitive payloads. Add safe correlation IDs and context. Production must not expose debug traces to users.
Rebuild the frontend
Identify Vite or Mix, Node version, package manager, lock file, source assets, and build output policy. Perform a clean build. Do not replace the bundler in the same change as a framework upgrade when risks can be separated.
Test SSR if present, Arabic RTL, accessibility, error states, and asset caching. Measure critical journeys before optimizing. A build completing does not prove user-facing compatibility.
Document deployment and rollback
Write the current sequence for pull, install, build, migrate, cache, PHP reload, workers, and SSR. Identify steps that cause downtime or logout. Rehearse risky migrations against a protected recent copy and measure locks.
Rollback is not just switching a commit when database, jobs, and payloads changed. Prefer expand-migrate-contract releases and backward-compatible jobs. The backup and continuity guide helps verify restoration instead of assuming it.
Upgrade in deliberate jumps
Read every official upgrade guide between current and target versions. Identify framework, package, and PHP changes. Establish green enough baseline tests first, then move one bounded layer at a time.
Use short branches, review, staging evidence, and monitored rollout. Avoid mixing broad renaming or a new architecture pattern into a security-driven dependency upgrade.
Produce a prioritized report
Separate immediate exposure, operational reliability, upgrade blocker, schedulable debt, and optional improvement. Every finding needs evidence, impact, a recommended option, an acceptance test, and an effort range only after discovery.
Software maintenance services can own remediation, but the report should remain executable by another qualified team. Tie work to issues and release decisions rather than a fear-inducing score.
Conclusion: earn the first package update
A Laravel takeover is ready for modernization when the team can reproduce the environment, run a baseline, explain requests and data, operate queues, deploy, restore, and roll back. Do not start with a broad composer update. Request a legacy Laravel takeover audit with an authorized repository, secret-free environment map, and two critical workflows.
