Retaining Computer Science Knowledge

Back at University, I didn't have problems remembering things, I was preparing one exam at the time and reviewing my knowledge all the time.
But now after 3 years of working as backend developer and data scientist, I really have problem to remember what I learned just few months ago. It feels like it's completely deleted from my brain. I guess main reason for that (except aging 😛) is not revising what i learned.

This article is talking about how to retain your computer science knowledge:

https://startupnextdoor.com/retaining-computer-science-knowledge/

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LeetCode Solutions Videos

Good explanations of solution and the code
Playlist contains 189 videos 🎬

https://www.youtube.com/playlist?list=PLU_sdQYzUj2keVENTP0a5rdykRSgg9Wp-

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What are the most common programming interview questions?

Companies keep refreshing and updating questions. BUT, regardless of that, there are certain algorithms that show up frequently.

Here are 5 very common ones. If you don’t know these then you’re probably not ready.

Graph Search - Depth-first and Breadth-first search
Binary Search
Backtracking using Recursion and Memoization
Searching a Binary Search Tree
Recursion over a Binary Tree

Of course, there are many others too.

Another thing to keep in mind - you won’t be asked these directly. It will be disguised as a unique situation.

Source: Harsh Goel

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Here are some good questions to ask at the end of the interview, extracted from various sources. The ones in bold are the ones that tend to make the interviewer go "That's a good question" and pause and think for a bit.


🔹General

What are you most proud about in your career so far?
What is the most important/valuable thing you have learned from working here?
How do your clients and customers define success?
What would you change around here if you could?
What are some weaknesses of the organization?
What does a typical day look like for you?
What do you think the company can improve at?
How would you see yourself growing at this company in the next few years?
Was there a time where you messed up and how was it handled?
Why did you choose to come to this company?
When you were last interviewing, what were some of your other options, and what made you choose this company?
What was something you wish someone would have told you before you joined?
What was your best moment so far at the company?

🔹Culture

What is the most frustrating part about working here?
What is unique about working at this company that you have not experienced elsewhere?
What is something you wish were different about your job?
How will the work I will be doing contribute to the organization's mission?
What do you like about working here?
What is your policy on working from home/remotely?
(If the company is a startup) When was the last time you interacted with a founder? What was it regarding? Generally how involved are the founders in the day-to-day?
Does the company culture encourage entrepreneurship? Could you give me any specific examples?

🔹Technical

These questions are suitable for any technical role.

What are the engineering challenges that the company/team is facing?
What has been the worst technical blunder that has happened in the recent past? How did you guys deal with it? What changes were implemented afterwards to make sure it didn't happen again?
What is the most costly technical decision made early on that the company is living with now?
What is the most fulfilling/exciting/technically complex project that you've worked on here so far?
I do / don't have experience in domain X. How important is this for me to be able to succeed?
How do you evaluate new technologies? Who makes the final decisions?
How do you know what to work on each day?
How would you describe your engineering culture?
How has your role changed since joining the company?
What is your stack? What is the rationale for/story behind this specific stack?
Do you tend to roll your own solutions more often or rely on third party tools? What's the rationale in a specific case?
How does the engineering team balance resources between feature requests and engineering maintenance?
What do you measure? What are your most important product metrics?
What does the company do to nurture and train its employees?
How often have you moved teams? What made you join the team you're on right now? If you wanted to move teams, what would need to happen?
What resources does the company have for new hires to study its product and processes? Are there specifications, requirements, documentation?
There's "C++" (or Python, Swift or any other tech) in the job description. How will you estimate my proficiency in this tech in 3 months?
How do you think my expertise would be relevant to this team? What unique value can I add?

🔹Product

Tell me about the main products of your company.
What is the current version of product? (If it is v1.0 or similar - there could be a lot of chaos to work with)
What products are your main competitors?
What makes your product competitive?
When are you planning to provide the next release? (If in several months, it would mean a lot of requirements specified in job description are not needed right now)
Is the team growing, and what sort of opportunities will there be in the next year/3 years?
What are your highest priorities right now? For example, new features, new products, solidifying existing code, reducing operations overhead?

🔹Management

These questions are suitable for asking Engineering Managers, especially useful for the Team Matching phase of Google interviews or post-offer calls that your recruiters set up with the various team managers.

How do you train/ramp up engineers who are new to the team?
What does success look like for your team/project?
What qualities do you look out for when hiring for this role?
What are the strengths and weaknesses of the current team? What is being done to improve upon the weaknesses?
Can you tell me about a time you resolved an interpersonal conflict?
How did you become a manager?
How do your engineers know what to work on each day?
What is your team's biggest challenge right now?
How do you measure individual performance?
How often are 1:1s conducted?
What is the current team composition like?
What opportunities are available to switch roles? How does this work?
Two senior team members disagree over a technical issue. How do you handle it?
Have you managed a poor performer at some point in your career before? What did you do and how did it work?
Where do you spend more of your time, high performers or low performers?
Sometimes there's a trade-off between what's best for one of your team members and what's best for the team. Give an example of how you handled this and why.
Give an example of a time you faced a difficult mentoring/coaching challenge. What did you do and why?
What is your management philosophy?
What is the role of data and metrics in managing a team like ours?
What role does the manager play in making technical decisions?
What is an example of a change you have made in the team that improved the team?
What would be the most important problem you would want me to solve if I joined your team?
What opportunities for growth will your team provide?
What would I work on if I joined this team and who would I work most closely with?

🔹Leadership

These questions are intended for senior level management, such as CEO, CTO, VPs. Candidates who interview with startups usually get to speak with senior level management.

How are you funded?
Are you profitable? If no, what's your plan for becoming profitable?
What assurance do you have that this company will be successful?
Tell me about your reporting structure.
How does the company decide on what to work on next?

🔹HR

How do you see this position evolving in the next three years?
Who is your ideal candidate and how can I make myself more like them?
What concerns/reservations do you have about me for this position?
What can I help to clarify that would make hiring me an easy decision?
How does the management team deal with mistakes?
If you could hire anyone to join your team, who would that be and why?
How long does the average engineer stay at the company?
Why have the last few people left?
Have you ever thought about leaving? If you were to leave, where would you go?

Out of 154 answers only 29% answered correctly. I guess we should start some training in this channel, from basic level :D

Most of you answered Python, yes it's easy to write code in Python, easier than in other programming languages, but the fact that it's to easy makes it really slow when it comes to computation.

In Python you don't have to write types of variables, but since you don't write it, it means computer needs to figure out type instead of you in runtime, which makes him slow.

Also Python is interpreted language, which means it Interpreter need to read and execute code in runtime. On the other hand, Java or C are compiled programming languages which means that your computer directly translates the program to machine code which could be understood by computer. This is done before you run your code, so no time is lost for conversion in runtime.

Btw if you didn't now, Python is created using C language, so when you run Python there are some C commands running underneath 😉

Hey guys,
I have created basic programming quiz. Quiz has 8 questions with multiple answers. When you finish it, you will get your position on the leaderboard.

This is first test quiz, if you like it we will create more and maybe even give some prizes to best ones on leaderboards. Your answers will remain anonymous.

You can take the quiz here:
http://t.me/QuizBot?start=Qf9xzJIx

🏆 Top results in the quiz 'Programming basics'

🖊 8 questions
⏱ 15 seconds per question
🤓 56 people took the quiz

🥇 Alpha1Beta2Tgeta3 – 8 (29.6 sec)
🥈 @Hmmm00 – 8 (33.2 sec)
🥉 @Subhanshu20135 – 8 (39 sec)
4. @Gfwfg – 8 (43.3 sec)
5. Sticker – 8 (49.6 sec)
6. @drago32123 – 8 (52.4 sec)
7. @sawyer_09 – 8 (55.1 sec)
8. PEE NA – 8 (1 min 16 sec)
9. Peter Ragnick – 7 (30.4 sec)
10. @Eraqus1 – 7 (36.6 sec)
11. @engineer951999 – 7 (45.1 sec)
12. @robleisrajkumar – 7 (47 sec)
13. @DeadSk0ll – 7 (51.6 sec)
14. Anonymous – 7 (57.9 sec)
15. Malik Hr – 7 (1 min 2 sec)
16. RAMYA NALLIBOINA – 7 (54.3 sec)
17. Mowli Dharan – 7 (1 min 3 sec)
18. @WiesmanY – 7 (59.1 sec)
19. @puni27 – 7 (1 min 3 sec)
20. Vaibhav Joshi – 6 (39.8 sec)

Data Structures series

Linked List

🔹 A Linked List is a linear collection of data elements, called nodes, each pointing to the next node by means of a pointer. It is a data structure consisting of a group of nodes which together represent a sequence.
🔹 Singly-linked list: linked list in which each node points to the next node and the last node points to null
Doubly-linked list: linked list in which each node has two pointers, p and n, such that p points to the previous node and n points to the next node; the last node's n pointer points to null
🔹 Circular-linked list: linked list in which each node points to the next node and the last node points back to the first node
🔹 Time Complexity:
Access: O(n)
Search: O(n)
Insert: O(1)
Remove: O(1)

What not to do during an interview

Don’t suck at something you say you’re an expert at
Seriously, how often do I talk to Java experts who don’t know how to use the most basic java.util classes? Or bash experts who don’t know how to grep? Or 3D math experts who don’t know anything about the dot and cross products? If you tell an interviewer you’re great at something she knows even a little bit about, she’s absolutely within her rights to test you on it. If you have no idea what she’s talking about, she’s going to start doubting everything on your resume. Don’t exaggerate your expertise.

Don’t make excuses for why you failed
Sometimes you get caught flat-footed, or your brain seizes up, or you have a bad day, or you go down the wrong path and get stuck. It happens, and a good interviewer gets that.

Don’t be arrogant, don’t act superior
Should be a no-brainer, right? And yet…

Don’t badmouth an old employer
Even if you worked for Satan in the helpdesk department of the third circle of hell, it’s unprofessional to trashtalk an old employer. Repeat after me: you had a great time and learned a lot, but it was time to move on.

Don’t swear

Don’t chatter on and on
You don’t want to be labelled a “talker”.

Don’t waste the interviewer’s (and your own) time
Don’t ask questions you can look up trivially. Don’t focus on irrelevant aspects of the job (gee, I hear you have catered lunches!).

Don’t get caught by an exploding offer
No company is going to give you an open-ended offer, valid until the end of time – but assuming your timetable is reasonable, most will be willing to hold on to an offer until you’re ready to make a decision (i.e., after you’ve finished your interviews).

Don’t get discouraged
The interview process is, to some degree, a stochastic process that can have little or no relationship to your actual abilities. Some interviewers and companies are better at it than others, but there isn’t a good way to know this ahead of time, and there isn’t much you could do about it, even if you did.

If you completely screw up with one interviewer, put it behind you and focus on acing the next. If you don’t get an offer, don’t take it as a statement on your personal worth. Take what you can from the experience, prepare the hell out of your next interview, and move on.

How long are coding interviews?
The phone screen portion of the coding interview typically lasts up to one hour. The second, more technical part of the interview can take multiple hours.

Where can I practice coding?
There are many ways to practice coding and prepare for your coding interview. LeetCode provides practice opportunities in more than 14 languages and more than 1,500 sample problems. Applicants can also practice their coding skills and interview prep with HackerRank.

How do I know if my coding interview went well?
There are a variety of indicators that your coding interview went well. These may include going over the allotted time, being introduced to additional team members, and receiving a quick response to your thank you email.

Don’t mistake the roles of your interviewers
There are generally three types of interviewers: HR, technical, and hiring managers. The HR representative is there to guide you through the process – meet you at reception, show you the coffee machine, give you a tour of the office, make sure the interviewers get to you on time, debrief you when all is done, and walk you out. Her involvement in the evaluation process will depend on the company, though she’ll almost certainly be watching for any HR-specific yellow or red flags.

Technical interviewers will make up the bulk of your interviewers. They’re there to determine if you have the technical chops for the job, and to decide whether you’re a good cultural fit. Some of them will be good interviewers, some bad. Some will have unconscious biases, others… will have stronger unconscious biases. Some will be in a good mood, others not. Some will be outgoing, others stoic. None will be able to tell you about your pay package, so don’t bother asking. It’s an unfortunate fact that your performance will likely be affected dramatically by who’s on the schedule the day you come in.

You’ll typically also meet the hiring manager at some point during the interview process. Some hiring managers will do technical interviews, some will focus on behavioral questions, and (if you’re doing well) some will focus mostly on selling you on the position. This is the person who will ultimately decide whether to fight for you – if you’re a questionable hire, she’s the one who can decide that you’re worth taking a chance on. If you’re an exceptional hire, she’s the one who’ll fight for a higher compensation package. A large part of her decision will be based upon feedback from the other interviewers, but ultimately she’s going to go by her gut.

How Long Should I Prepare for a Coding Interview?
Coding interview preparation time largely depends on the interviewee's level of experience. If you're an entry-level programmer, it's a good idea to spend at least twelve weeks preparing. If you have more experience, 4-8 weeks is suggested for interview prep.

Study the company's programming language and tools of choice. Practice a couple of coding challenges each day — don't let your practice be a cram session right before your coding interview. Finally, as you practice, make sure to time yourself to see how you are progressing.