Gronex

What it does

LeetCode trains you for algorithms. Real backend rounds hand you an unfamiliar repository and ask you to find the bug and make the tests green. Gronex is practice for exactly that, in your browser, with no setup. Java, Python, Node.js and C++. Concurrency races, database incidents, API contract bugs, heap dumps and GC logs. Free problems run without an account.

Practice real backend interview repositories: implementation, database engineering, heap and thread-dump debugging, GC-log analysis, concurrency, and API failures in Java, Python, Node.js, and C++.

LeetCode trained you for algorithms. Real backend rounds hand you an unfamiliar repo and ask you to find the bug and make the failing tests green. Practice exactly that — in your browser, no setup — across Java, Python, Node.js and C++, from concurrency races to database incidents and runtime failures. $ ./verify.sh PASS OrderServiceTest.createsOrder PASS OrderServiceTest.appliesDiscount FAIL OrderServiceTest.processesConcurrentCheckouts expected inventory: 0 actual inventory: -7 ← race condition 2 passed, 1 failed Find the bug. Fix it. Make it green. For hiring teams Gronex for Teams — run live technical interviews on real repository problems. Learn more → Why this is different Practice…from gronex.org

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• LB
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