Show HN: I made a spaced repetition tool to master coding problems (lanki.xyz)

score = ( timeSinceLastAttempt ^ 2 ) * difficulty;

Anything else you'd want factored in?

I take it you solve puzzles by writing code. How does it help with job interviews really?

https://alpine-aspen-2ab.notion.site/Lanki-da1481129bfa4d3ca...

The people / companies using it to hire will tend to hire people who studied leetcode.

The companies that don't use leetcode / don't use it as a strong signal will continue not using it.

In my opinion, leetcode is a poor signal if used as a binary decision ("were they right or wrong?"). The more important thing is communication and how they worked through the problem. I've heard this multiple places and I absolutely agree: attitude over aptitude. You can teach knowledge, you can't teach attitude or ability to problem solve.

The companies that use them as a strong signal are the ones that will be absolutely demolished in engineering because they are on a fast track for a staff full of rote memorization rather than strong creative problem solving. They'll be handicapped when it comes to solving problems that aren't covered by leetcode because no one there bothered to learn it.

I applied to Atlassian as a 50 year old from South Africa who has very broad and deep experience but has never worked in big tech. Failed at the last interview (of 5) but I found the process and feedback very fair and much better than others I’ve seen elsewhere. The focus was on collaboration and communication and not being a jerk, along with the problems to be solved. I enjoyed it.

It feels obvious to me that, in theory, we could do a lot more to leverage your current world knowledge to recommend the next piece of educational content, to optimize not just your understanding but also other things like how engaged you are. For example, a system could throw you an easier question if it helps you focus longer.

When I see the state of current interview prep it’s mostly “here’s a big list of questions” , perhaps tagged by difficulty and grouped under related topics such as “graph problems” or “tree problems” but I’m personally convinced a more sophisticated system could serve you the best possible next problem to stretch your brain in the right way.

Spaced rep is simply the proven starting point. The rest of adaptive learning has a bit of a troubled past because it was trendy to VCs , but pushed on educators and presented more as an alternative to a teacher rather than something to augment a teacher. I worked for a company that raised 100M+ to work on it but the CEO was great at terms sheets but uninterested in actually building a great education project.

But the reason that I joined the company was the high level idea still resonates with me. Surely many HN users have a big list of things they want to learn- perhaps about LLMs. But a typical course will have zero knowledge on where you’re starting as a student . It might bore you with stuff you know already or take for granted key prerequisites and skip them.

Anyway, I’m currently building my own adaptive learning platform but focused on helping professional poker players learn game theory . My idea being that it’s an easier ed tech app to bootstrap as the knowledge very directly translates to money. And really the same criticism applies because you can’t truly memorize a game tree , it’s more important that you build a high level conceptual understanding. But , as much as rote memorization deserves to be maligned when done in isolation, it’s not so bad when done as part of a broader learning strategy. For example, you can’t memorize vocab to learn Spanish but certainly knowing 5000 words in Spanish is a very nice starting point compared to not knowing any words. And tools like spaced rep have been proven by research to help with that goal and I view as a pathway to more broad adaptive learning strategies.

Traditionally, yes. But several people use the SR algorithm to simply do the same problems over and over (practice), without the memorization component.

Looking at a typical SR algorithm, you're not really going to memorize doing the same medium/high Leetcode problem unless you actively try to memorize it. The interval sequence will be something like: 2, 5, 13, 35, 120, etc. By repeatedly solving the problem so few times in such a long period (and while solving other problems at the same time): You're not really going to memorize it accidentally.

1) Learning for mastery / competency to apply the skills to real life endeavors

2) Learning so you can meet some standard necessary to enable certain opportunities in life

It seems your opinion comes from a personal value bias towards #2 and I share that bias, but perhaps not as dominantly as you do (at the moment). For both of these, memorization can be very helpful, even optimal. But the application of spaced repetition would be different depending on the goal.

On memorization applied to learning for genuine personal mastery:

I believe memorization is optimal for foundational axiomatic knowledge. A good example is quick addition and times tables (and other arithmetic). I believe:

1) People should consider it a necessary life skill to be able to perform reasonably complex arithmetic manually in your head. For example, 4462+9241=13703 or 25120=3000. Many people will disagree on the nuances on where this begins and ends, and that's okay. For example some people will feel that people should be able to multiple 27123 in their head, others would feel it's okay for something like that to be done on paper. But for me, the point is that there exists a category like "things you should be able to do, but it's fine not to have memorized". More importantly, I believe it would be suboptimal to spend a significant amount of your life memorizing an increasing sample of these, but it's reasonable to spend time maintaining the skill of manual mental arithmetic and probably reasonable to spend time improving the speed and accuracy with which you do it.

-- 1a) A nuanced subset of this skill example is "estimation", for situations where it's appropriate. It might take longer for some people to manually calculate 27123 (or whatever) than for them to pull out their cell phone or ask their Apple Watch. If the situation only needs them to have an upper and lower bound within they might break it down to {lower_bound = 25120 = ((256)2)10 = (150210) = 3000; upper_bound = 30125 = 3055 = 150510/2 = 75010/2 = 7500/2 = 3750} and they could determine the answer is around 3350 or so, but absolutely 100% definitely between 3000 and 3750. And they could still do this type (if not degree) of estimation faster (and more stealthily, which can be important sometimes, like during negotiations/haggling) than pulling out a cellphone and calculating.

2) People absolutely cannot do arithmetic if they do not have certain foundational axioms memorized. If you do not have 1+1=2, 2+1=3, 3+1=4, etc memorized (counting), you literally cannot do arithmetic. That would be an absurdly low-functioning adult and essentially means you don't know how to count. But technically* you only need to be able to count to add, subtract, and multiply (by maintaining two counts simultaneously) any real numbers. Obviously just counting is a helpful, but not optimal, level of memorized knowledge to be competent at arithmetic. It would plainly be helpful to also memorize things like 7+6=13 and 152 = 30, and have instant recall for these rather than re-calculating them manually every time you need them. Which brings me to:

-- 2a) I believe it is helpful to memorize more than what many people think it is helpful to memorize. We generally are taught in primary school to memorize times tables up to 10x10. But perhaps it would be useful to extend this beyond 10x10, at minimum for some additional prime numbers which might show up frequently and cannot be quickly factored to smaller numbers. I could see it being super nice to have my times tables memorized up to 100x100, and additional addition/substraction memorized. I feel this way because despite having done well in three semesters of calculus and differential equations, I have alway...