Building Web Apps with Laravel Module 19
Interview preparation and timed practice: questions
Questions on interview preparation and timed practice: short warm-ups, then what each harder question tests, the first step of a good answer and its follow-ups.
Warm-up questions
Short questions with short answers, each answered in full.
-
Fresher
What is the difference between bind() and singleton() in Laravel's service container?
Answered in the lesson Laravel interview concepts and question bank
-
Fresher to mid
In what order do two route middleware run around the controller, and when does terminate() run?
Answered in the lesson Laravel interview concepts and question bank
Questions with model answers
What each question tests, the first step of a good answer and the follow-ups to expect.
-
Mid to senior
Pathshala's batch report shows 25 batches a page, each with its teacher and its number of enrolled students, and it sends 52 queries a page. Bring it to a fixed number, keep it there with a test, and say what changes when an export must cover 5,000 batches.
- What it tests
- Measuring a query count before changing code, eager loading and counting without a query per row, a test that fails when the count grows, and exporting a large table in constant memory.
- First step
- Account for all 52 before touching the code: one count query for the paginator, one for the page of batches, and one teacher and one student count for each of the 25 rows. Then fix the two per-row reads, and only then write the test that pins the new number.
- Follow-ups
-
- Why does withCount() add no query of its own, while with() adds one?
- Your test expects 3 queries and fails with 13. Where would you look first?
- When would you switch on automatic eager loading instead of writing with() calls?
From the lesson Laravel interview concepts and question bank
Model answer, Pro. Model answers open with any pass; prices are in the notice on this page.Opening the model answers with your pass…
Model answers open with any MySmartCoPilot pass.
- Pro pass · 1 week₹79$2.99
- 30 days₹179$5.99
- 1 year₹1,699$45
One payment; a pass never renews. The price shown is the total you pay: no fees or charges are added at checkout.
Passes can’t be bought right now, so the model answers can’t be opened at the moment. If you have a pass, enter your licence key.
It also opens every other in-depth part in Learn and every Pro tool. Sales are final, except where the law gives you a right to withdraw, for example in the EU and the UK (refund policy).
In the answer:
- Model answer
- Follow-up answers
- Common mistakes
- Rubric
- Variants
- about 4 minutes
-
Senior to staff
Pathshala's receipt job waits on a slow mail server, the queue retries it, and a guardian receives two receipts for one payment. Explain the ways a Laravel job can run more than once, make the receipt safe to repeat, and say how a test proves it.
- What it tests
- Knowing that a queued job can run more than once, naming the retry paths and the timeout settings, and making the side effect idempotent with a key the database enforces.
- First step
- Assume the job will run twice and design for it. List how that happens: an exception with tries left, a timeout, a worker that dies before it deletes the job, a timeout longer than retry_after, a manual retry. Then find the side effect, the mail, and guard it with a row the database keeps unique.
- Follow-ups
-
- Why does ShouldBeUnique not stop the second receipt?
- How must --timeout and retry_after relate, and what happens when they do not?
- The mail server accepted the message but timed out before it answered. What does your design send?
From the lesson Laravel interview concepts and question bank
Model answer, Pro.In the answer:
- Model answer
- Follow-up answers
- Common mistakes
- Rubric
- Variants
- about 4 minutes
All Building Web Apps with Laravel interview questions · The Building Web Apps with Laravel track