Just ended recently Oracle The complete interview process of 26NG SDE, from Screening to five rounds of VO to HM call, the overall rhythm is very tight, with almost no "losing" rounds. Screening met a very friendly Chinese interviewer, with smooth communication and a good experience. However, after entering VO, the style of interview changed significantly. The consecutive rounds of technical interviews were very pushy, with intensive questioning, and overall they were more biased towards the examination of engineering capabilities in real work scenarios.
Phone Screening
The topic of Screening is to use Golang to implement a simplified Redis-like data structure. The interviewer first briefly confirms language proficiency, and then goes directly to coding without much preparation.
The core requirement is to design a key-value storage structure that can support both string and list, which needs to be implemented Set,List.push,Get And List.remove Wait for operations. The rules of remove are relatively detailed: count > 0 deletes the first N items, count < 0 deletes the next N items, and count = 0 deletes all. Also, expiration is mentioned, but it is clearly stated that it can be deferred, and the implementation idea is enough.
The real test in this round is not grammar, but abstraction ability-how to unify the storage of different data types? Should I use interface or struct? How to avoid unnecessary traversal of list deletion? Halfway through writing, the interviewer will also ask about the time complexity and how to optimize it if the amount of data increases.
The whole thing is more like a combination of mini system design + coding. As long as the structure is clear and the code is clean, it is basically stable.
VO Round 1 – LRU Cache
The first round of VO is a classic LRU cache, without any foreshadowing, just let you talk about your ideas and then start writing.
The conventional solution is of course HashMap + Doubly Linked List. The key point is to ensure that both get and put are O(1). However, Oracle's interviewer was obviously not satisfied with the template answer. After writing it, he immediately started to follow-up: What if it is a multi-threaded environment? How to reduce lock contention? Is there a more scalable solution?
The feeling of this round is that the questions are not difficult, but the depth depends on how much engineering you can talk about. If you only stay at the LeetCode level, it is easy to continue to ask questions.
VO Round 2 – Merge Sorted Lists
The rhythm of this round is very typical: start with a relatively simple merge two sorted lists, and when you finish writing quickly, immediately upgrade to Merge K Sorted Lists.
The interviewer is actually observing two things: whether you take the initiative to analyze the complexity, and whether you know a better solution. After writing the double linked list solution, if you mention that you can use min heap to reduce the complexity to O(N log K), you will basically be considered to have a mature idea.
The overall pressure of this round is not high, but the basic skills are very much tested - it is a question of "you can't fail, but you can widen the gap".
VO Round 3 – Delete Target Leaf Nodes from Binary Tree
The third round is a typical recursive tree problem: delete all leaf nodes whose value is equal to target. But the real difficulty is that when leaf is deleted, its parent node may become a new leaf, and further judgment needs to be made.
This is actually to test whether you have good recursion design capabilities, such as whether you know how to use post-order traversal, and whether you can directly tell the parent node "should I be deleted" through the return value.
The interviewer looks at the readability of the code very carefully, including naming, structure, and whether there is redundant logic. If you write it down as a whole, you will find that Oracle does have requirements for "production-style code", rather than just whether it can AC.
VO Round 4 – Project Deep Dive + Coding
The first half is a deep dive into your resume, and it's very detailed. From why the system is designed like this, to tradeoffs, to how to optimize it if it is reworked, almost every point will be questioned. In fact, many people are not hung up on coding, but stuck here - because they are not familiar enough with their projects.
The second half of the coding is to design a Hospital Appointment Booking API. The scenario is that there are 1000 doctors in the hospital, and each doctor works from 9AM to 5PM, one slot every 15 minutes. The API needs to book the "earliest available" time for a given doctor on a given day and maintain state across multiple POST requests.
This question is essentially about lightweight system design. How to model doctor and slot? How to quickly find earliest availability? How to avoid double booking? What if there is concurrency? As soon as you start talking proactively about optimistic locking, data structure selection, or state management, the interviewer will usually nod frequently.
This round is very much about engineering thinking, not algorithmic skills.
VO Round 5 – Hiring Manager Call
The last round is HM behavior, there is no algorithm, but don’t let your guard down. The interviewer focused on two directions: How do you usually do prioritization? How do you deal with a system failure that affects customers? The main thing is not to ask you to memorize STAR, but to see if you think like a reliable team member.
For those of you who are preparing for Oracle
If you are also preparing for VO from Oracle or other major companies recently, it is actually very important to be familiar with high-frequency questions in advance. Many interviews may not seem difficult, but once they are followed up continuously, people who are not systematically prepared can easily get stuck on the spot. We have compiled a large number of real coding and VO questions here, with very high coverage, which can help you quickly establish correct problem-solving and response ideas.
Also, if you are not sure about your on-the-spot performance, you can also check out programhelp Interview assistance support . There are mature assistance plans for key aspects such as OA and technical aspects, and the overall process is safe and stable. Preparation in advance + reasonable support is often more stable than carrying it out temporarily.
