How to protect a system from replay attack when designing a public REST API?
Middle+
8
Python
11501
584
What is the difference between the locking strategies SELECT ... FOR UPDATE and SELECT ... FOR SHARE? Describe a practical case for each.
Middle+
6
What is the difference between asyncio.gather and asyncio.as_completed? In which situations is one method preferable over the other?
Middle+
6
What is the 'index bloat' problem in PostgreSQL, why does it occur due to MVCC mechanics, and how to deal with it?
Middle+
6
How does the CQRS (Command Query Responsibility Segregation) pattern differ from the traditional CRUD architecture? When is its implementation justified?
Middle+
5
How is the mechanism of Context Variables (contextvars) organized and why does the usual threading.local not work inside asyncio coroutines?
Middle+
5
What is a non-repeatable read anomaly and at what minimum transaction isolation level does it completely disappear in PostgreSQL?
Middle+
5
Describe a scenario where Python's garbage collector cannot automatically delete objects from memory, even if there are no more references to them in the code.
Middle+
5
What is a Server-Side Request Forgery (SSRF) vulnerability and how should a backend developer validate incoming data to prevent it?
Middle+
5
How to design a distributed lock using Redis? What edge cases should be considered to avoid race conditions?
Middle+
4
What is Amda's law and how is it applied in evaluating the efficiency of backend scaling?
Middle+
4
Опишите разницу между стратегиями доставки сообщений at-least-once и exactly-once в брокерах, например Kafka. Какие требования это накладывает на Python-бэкенд?
Middle+
4
What is the internal mechanism of the async and await keywords in Python? What happens at the generator level?
Middle+
4
How does the Outbox Pattern help ensure that a message in a message broker like RabbitMQ is sent only if the transaction in the relational database has completed successfully?
Middle+
4
What is the difference between stateful JWT-based authorization with token blacklists and stateless JWT? What are the trade-offs in security and performance?
Middle+
4
How can one write a custom metaclass that automatically adds a prefix to all methods of the created class?
Middle+
3
How to architecturally solve the problem of write amplification (excessive disk writes) when using NoSQL databases under high update intensity?
Middle+
3
Imagine a situation: a heavy analytical query SELECT COUNT(*) FROM large_table is executed in PostgreSQL. Will an index on the primary key help speed up this query? Why?
Middle+
2