20 questions for a Backend Engineer (Distributed Systems)

Quick answer: Probes consistency, idempotency, observability, and pragmatic CAP trade-offs.

How to use this bank

Pick 3–5 questions per loop, not all of them. Score each on a 1–5 rubric immediately after the conversation — never trust your memory. Pair this bank with a scorecard and a structured debrief.

What to probe for

Event-sourcing vs CRUD, retries & exactly-once, hot partitions, blast-radius design. Calibrate with one teammate before running it on a real candidate — drift is the single biggest threat to fair, accurate interviewing.

Scoring rubric (1–5)

1 = unable to engage; 2 = surface-level; 3 = solid working answer; 4 = nuanced trade-offs with prior reps; 5 = teaches the interviewer something.

Red flags to log

Blaming previous teams, no metrics in stories, vague timelines, can't articulate trade-offs, defensive to follow-ups.

Where to go next

Run a structured debrief (see Hiring Best Practices), then move strong candidates to your Pipeline. Always send a decline within 5 business days — templates in Decline a candidate gracefully.

Step-by-step checklist

• Confirm you are in the correct CosmoQuick surface: Candidate Dashboard, Recruiter Dashboard, ATS, Tools, or Settings
• Search the command palette for the feature name before browsing menus manually
• Open the relevant object (job post, candidate, application, invoice, or workspace) and check its status
• Make one change at a time, save, refresh, and verify the expected result
• If the issue still appears, capture the page URL, screenshot, browser, account email, and last action before contacting support

Practical example

A common real-world case: a user signs up as a candidate, then realizes they need recruiter features such as posting jobs, Resume Rank, MIRA, or candidate pipelines. First check Settings → Account for account type or dual-mode controls. If switching is not available for your plan or workspace, export any candidate data you need, then either contact support to convert the account safely or create a fresh recruiter account with the correct work email.

Screenshot placeholder

[Screenshot placeholder: show the exact CosmoQuick screen, highlighted button, empty/error state, and the expected success state. Keep sensitive candidate, salary, invoice, and contact information blurred before sharing.]

Troubleshooting guidance

• If a button is missing, check your account type, plan, workspace role, and whether the page is available only on recruiter or candidate mode
• If data looks stale, refresh the page, clear filters, and check whether you are viewing the right workspace or role
• If search returns nothing, try broader terms, remove hard filters, and search by skill, role, company, email, or candidate name
• If a payment, activation, import, or integration fails, retry once and then send the error text plus screenshot to support
• For urgent hiring blockers, use WhatsApp support from the Help Center

Pro tips

• Pair every question with a 1–5 scoring rubric before the interview — not after.
• Use one behavioural + one technical + one role-specific question per 45-min loop.
• Calibrate scores across interviewers monthly — drift is the silent killer of hiring quality.

Common pitfalls

• Reusing the same question for two years — answers leak to Glassdoor/Blind quickly.
• Asking trivia ('what does this CSS property do?') instead of judgment ('how would you debug…').
• Scoring on personality instead of demonstrated behaviour.

Frequently asked

Are these questions safe to use as-is?

Yes — every prompt is reviewed for bias and EEOC compliance, but adapt them to your stack and seniority bar.

Do you have answers and rubrics?

Yes — each article includes a model answer outline and a 1–5 rubric you can paste into your scorecard.

Key takeaways

• Most CosmoQuick issues come from account type, workspace context, plan limits, filters, or incomplete setup
• Recruiter tools and candidate tools intentionally live in different dashboards to protect privacy and reduce confusion
• The fastest fix is usually: verify mode → clear filters → inspect status → search docs → escalate with context
• Keep this article open while performing the steps so you can compare the expected and actual state

Next steps

• Browse all categories for related guides
• Open the Help Center home to keep exploring
• Still stuck? Contact our team — average reply under 4 hours on weekdays