10 Questions to Ask Before Hiring a Senior PHP Developer

1. Walk me through a system you owned end-to-end.

Listen for: how they made trade-offs, what they'd do differently, how they handled production incidents. Vague answers ('I worked on a big platform') are a red flag.

2. What's the worst PHP codebase you've worked on, and how did you make it better?

Seniors love this question because they have war stories. Juniors usually don't have a strong answer — or claim every codebase was 'fine'.

3. When would you NOT use Laravel?

Anyone who says 'always use Laravel' isn't senior. Real answers: tiny scripts, very specific performance constraints, existing Symfony shops, FaaS-style workloads.

4. How do you handle background jobs that fail?

Look for: idempotency, retries with backoff, dead-letter queues, alerting. If you hear only 'retry', they haven't run jobs in production at scale.

5. How do you keep PHP code fast as the database grows?

Expect: indexing strategy, N+1 query awareness (eager loading in Eloquent), caching layers, query profiling tools (Telescope, Clockwork, Blackfire).

6. How do you ship code safely?

Listen for: feature flags, staging environments, automated tests, blue/green or canary deploys, rollback plans. 'We deploy on Friday afternoons' is a joke seniors don't make.

7. How do you decide what to test?

Mature answer: critical business logic and integration boundaries get the most coverage; UI gets smoke tests. Beware of 'we test everything' — that's either untrue or wasteful.

8. How would you onboard yourself to our codebase?

Good signal: they ask about docs, run the project locally, read the test suite, talk to whoever wrote the gnarliest module. Bad signal: 'I'll just read the code'.

9. Tell me about a disagreement with a PM or designer and how you resolved it.

Seniors push back with data and alternatives, not ego. Juniors either capitulate or escalate.

10. What would you ask me to know if this engagement is a fit?

The best engineers interview you back. They want to know about decision-making speed, technical debt tolerance, and on-call expectations. If they have no questions, they're either desperate or disengaged.

Bonus: the small paid trial

After the interview, run a 4–8 hour paid trial on a real, low-risk task. You'll learn more about how someone works in one afternoon than from any interview.