frontpage.
newsnewestaskshowjobs

Made with ♥ by @iamnishanth

Open Source @Github

fp.

Open in hackernews

“Design me a highly resilient database”

https://nikogura.com/DatabaseDesign.html
47•donutshop•4d ago

Comments

noemit•4d ago
Hiring good engineers is not that hard. Why do we keep screwing this up?
keyle•1h ago
If anything it shows the applicant was over qualified and it probably wasn't a great fit; to have this guy, who has battle experience, in a place where the interviewer was looking for a one-size-fit-all canned type answer.
rockemsockem•1h ago
Hard for a bad engineer to hire a good one maybe? If so, not the biggest problem to have.
pinkmuffinere•1h ago
> Hiring good engineers is not that hard

I feel this is misleading. I think a reasonable definition of a 'good' engineer is engineer in the 75th percentile and above for their craft. You can debate other definitions, I'm not saying this is the only reasonable one. But by this definition, I think you can immediately see that it is hard -- given 4 engineers, we expect that only one of them is "good". And what if your standards are higher? What if you only want _great_ engineers? I can't believe that it's easy.

carefree-bob•39m ago
It's hard because people are threatened by good people and don't want to hire them, and also objective standards leave less wiggle room to sneak in your friends or others in your peer group.

Many, many forces lined up against meritocracy. All the incumbents, for example, tend to have something to lose, but it's the incumbents who decide if you are hired.

It's a miracle that there are any good companies once the original owners are gone.

mcny•28m ago
If I am hiring, I need these characteristics:

1. Person who cares 2. Person who is knowledgeable 3. These two must be the same person!

kulahan•9m ago
Please explain how to hire good engineers. This is a question literally only you have figured out, so your knowledge would be extremely useful here.
tintor•1h ago
You are better off not working there.
scrubs•1h ago
The interviewer question was adversarial... don't think it puts them in a good light.

More importantly I appreciate the OP for describing lessons learned through this hard experience. I worked in finance: Cassandra is no kind of answer for systems of record

Thanks

andersa•1h ago
> At Apple Pay, we processed millions of daily transactions across 30,000 servers

Why does it require 30,000 servers to process millions of daily transactions? Is there a typo in the amount?

dworks•49m ago
Maybe globally spread out POS servers if that's how it works?
carefree-bob•41m ago
This can be read in two different ways
wrs•1h ago
I really appreciate that your response to being interviewed by an idiot is to write, not an angry rant, but an educational blog post. You are a good person and they didn't deserve you.
joeconway•38m ago
Having worked with Nik in the past, yes he is a great person and one of the best. Any company missing out on him is genuinely foolish
wewewedxfgdf•1h ago
The best interview question to find great developers is this:

"What number am I thinking of?"

Smart developers - really smart developers are always right. Truly great developers have seen this sort of problem before and know how to attack it - they need no fancy questions or "deeper understanding". They simply hit the whiteboard, do the logic and output the answer.

Don't settle for anything except A players.

doublerabbit•1h ago

    % isIt3
    10
    0
    6
    4
    8
    0
    9
    5
    I found three
    ----
    proc isIt3 {} {
     variable 3 [expr {int(rand()*12)}]
      switch $3 {
       3 { puts "I found three" }
       default { puts "$3" ; isIt3 }
      } ;# end switch
    } ;# end proc
The number you're thinking of is 3. (-:
bitwize•33m ago
So how well would a candidate do if they looked at that and thought "whoa, is Tcl really tail recursive?!"
tmoertel•52m ago
> "What number am I thinking of?"

I don't think this is a good interview question, but I do think it is interesting as a thought exercise.

I bet that perhaps 25% of candidates could actually answer the question correctly, even if they didn't know anything about Schelling points. It could also lead to some nice discussions about how to solve an open-ended problem, probability distributions, strategies for maximizing payoffs when making decisions in the face of uncertainty, and so on. The question is so bad, it's actually kind of good.

fogzen•43m ago
What answer are you looking for?
jasonwatkinspdx•33m ago
I'm glad you ask this, as it signals very clearly the need to get up and walk out of the room.

Same with your last sentence.

roncesvalles•24m ago
The solution to this entirely depends on whether you are willing to answer other questions about the number and of what nature. Would you answer: is it higher/lower than X? How about how many digits there are?

But assuming you are unwilling to answer any additional questions, the correct solution is to simply brute force every number up from 0 and its negative.

mooreds•8m ago
_thinks: "gotta be a sarcastic comment"_
JSR_FDED•1h ago
I think it’s a great interview question. Open-ended, rewlly leads to a good discussion that can give you a sense of how the applicant approaches a problem and thinks it through.

Disastrous in the hands of an interviewer who’s looking for a one word answer.

LPisGood•1h ago
I’m not usually one to complain about AI being used to generate content because I find this and especially interesting topic, but it really took me out of it.

More relevant to the topic at hand, I feel like I didn’t put that much thought into designing my interview questions, but I’m always astounded when I read these sorts of descriptions of other interview questions. There should perhaps be some formal training or certification or something for asking good engineering interview questions.

Freedom2•26m ago
There was one person on this site who looked down at candidates (for a normal software development job) who didn't answer his interview question well. And by well, I don't mean being curious and working it out on the fly, I mean that if the candidate didn't know the answer of the top off their head, the HN commenter deemed them uncurious and unsuitable. The question?

"How do mobile phone towers work?"

glenpierce•21m ago
Electricity goes in and phones come out, duh.
getnormality•1h ago
Good time to stand up, shake hands, say "we'll be in touch!" and leave.

Sometimes you gotta fire your interviewer.

8note•53m ago
something is off here.

naming "cassandra" is not designing a database.

it feels like there was some miscommunication along the way

bitwize•31m ago
Bahahahahahaha.

You sweet summer child.

The things I've seen at certain worksites...

skydhash•45m ago
I'm glad I read the "Designing Data Intensive Applications" book because I get the full context of the blog.

And the lesson of the blog is why forcing LLM usage is stressful to some engineers. Most implementations are in a quantum state and the back and forth to have clear requirements is what can make the wave function collapse. We know all the possible answers , but all of them are equally valid.

We could go with the LLM route and just do a quick guess on the answer, but "Accountability" and "Professionalism" prevent us from doing so.

tantalor•44m ago
/dev/null is pretty resilient
carefree-bob•44m ago
I like your style
mcny•31m ago
The database is resilient. Your data is not
doublerabbit•42m ago
> The answer he was looking for was ‘Cassandra’. “You’d have a hard time having it NOT be resilient.”

A "database" that starts to fall if the ring in the cluster becomes choked? Draining a broken Cassandra ring and under high load is hell and ball clenching.

Especially hoping that another Cassandra node doesn't fail under high load. Pish, Erlang and mnesia.

tombert•13m ago
At a job interview in 2016, I was given a fairly typical "design Twitter" whiteboard problem, so I started doing a fairly typical thing involving load balancers and Nginx and the like.

The topic of the database came up, and I asked "Do we care more about consistency or availability?".

He responded back with "we want both".

I said "I mean, I would like both too but I'm pretty sure we can only get one"

He disagreed and we went back and forth, and eventually I pull out my phone and pull up the Wikipedia for CAP theorem. He eventually (and begrudgingly) agreed and said "umm, I guess availability", so I used Cassandra and moved on with it, though five minutes were wasted with this pointless argument.

To be fair, they did make me an offer, and it was even a decent enough offer (though I ended up taking a different job), but I remember being kind of flabbergasted that I had to explain CAP theorem to a person who had like a decade more experience than I did. It's not like CAP theorem is this super deep arcane topic; I'm pretty sure it's one of the first things you learn about when getting into distributed systems. It was certainly one of the first thing that I learned about.

nubg•2m ago
> Not because it’s trendy. Because ACID compliance

> The CAP theorem is not a suggestion. It’s a mathematical proof.

> this is not a philosophical inconvenience. It’s a compliance violation.

@dang, i thought we just banned AI written blog posts?

I know I will get downvoted for this everytime I post this comment, but I'm sick and tired of 80% of everything being written/heavily edited by AI.

Can the author not just use his own words? Is he really that bad at writing? But somehow the content is supposed to ne worth my time?

I'd rather read the prompt instead, so I know which parts the author actually meant to say, rather than wondering which parts the AI invented to make it sound flowery and punchy, the Tiktok style of prose.

Shall I implement it? No

https://gist.github.com/bretonium/291f4388e2de89a43b25c135b44e41f0
918•breton•6h ago•334 comments

"This Is Not the Computer for You"

https://samhenri.gold/blog/20260312-this-is-not-the-computer-for-you/
35•MBCook•1h ago•9 comments

Malus – Clean Room as a Service

https://malus.sh
1080•microflash•13h ago•409 comments

Bubble Sorted Amen Break

https://parametricavocado.itch.io/amen-sorting
269•eieio•9h ago•87 comments

Reversing memory loss via gut-brain communication

https://med.stanford.edu/news/all-news/2026/03/gut-brain-cognitive-decline.html
247•mustaphah•10h ago•101 comments

ATMs didn’t kill bank teller jobs, but the iPhone did

https://davidoks.blog/p/why-the-atm-didnt-kill-bank-teller
345•colinprince•12h ago•385 comments

Document poisoning in RAG systems: How attackers corrupt AI's sources

https://aminrj.com/posts/rag-document-poisoning/
77•aminerj•13h ago•33 comments

The Met releases high-def 3D scans of 140 famous art objects

https://www.openculture.com/2026/03/the-met-releases-high-definition-3d-scans-of-140-famous-art-o...
240•coloneltcb•11h ago•50 comments

Understanding the Go Runtime: The Scheduler

https://internals-for-interns.com/posts/go-runtime-scheduler/
40•valyala•3d ago•3 comments

Innocent woman jailed after being misidentified using AI facial recognition

https://www.grandforksherald.com/news/north-dakota/ai-error-jails-innocent-grandmother-for-months...
439•rectang•6h ago•223 comments

US private credit defaults hit record 9.2% in 2025, Fitch says

https://www.marketscreener.com/news/us-private-credit-defaults-hit-record-9-2-in-2025-fitch-says-...
279•JumpCrisscross•14h ago•363 comments

“Design me a highly resilient database”

https://nikogura.com/DatabaseDesign.html
47•donutshop•4d ago•37 comments

Launch HN: IonRouter (YC W26) – High-throughput, low-cost inference

https://ionrouter.io
51•vshah1016•8h ago•21 comments

Forcing Flash Attention onto a TPU and Learning the Hard Way

https://archerzhang.me/forcing-flash-attention-onto-a-tpu
49•azhng•4d ago•12 comments

WolfIP: Lightweight TCP/IP stack with no dynamic memory allocations

https://github.com/wolfssl/wolfip
99•789c789c789c•11h ago•13 comments

Big data on the cheapest MacBook

https://duckdb.org/2026/03/11/big-data-on-the-cheapest-macbook
318•bcye•15h ago•258 comments

Show HN: OneCLI – Vault for AI Agents in Rust

https://github.com/onecli/onecli
126•guyb3•10h ago•40 comments

IMG_0416 (2024)

https://ben-mini.com/2024/img-0416
10•TigerUniversity•3d ago•1 comments

Are LLM merge rates not getting better?

https://entropicthoughts.com/no-swe-bench-improvement
123•4diii•15h ago•112 comments

Show HN: Axe – A 12MB binary that replaces your AI framework

https://github.com/jrswab/axe
154•jrswab•13h ago•98 comments

NASA's DART spacecraft changed an asteroid's orbit around the sun

https://www.sciencenews.org/article/spacecraft-changed-asteroid-orbit-nasa
109•pseudolus•4d ago•79 comments

Long overlooked as crucial to life, fungi start to get their due

https://e360.yale.edu/features/fungi-kingdom
99•speckx•13h ago•33 comments

DDR4 Sdram – Initialization, Training and Calibration

https://www.systemverilog.io/design/ddr4-initialization-and-calibration/
81•todsacerdoti•2d ago•17 comments

The Cost of Indirection in Rust

https://blog.sebastiansastre.co/posts/cost-of-indirection-in-rust/
90•sebastianconcpt•3d ago•40 comments

Converge (YC S23) Is Hiring a Founding Platform Engineer (NYC, Onsite)

https://www.runconverge.com/careers/founding-platform-engineer
1•thomashlvt•10h ago

Language birth

https://asteriskmag.com/issues/13/language-birth
21•mitchbob•2d ago•3 comments

Returning to Rails in 2026

https://www.markround.com/blog/2026/03/05/returning-to-rails-in-2026/
343•stanislavb•20h ago•216 comments

The Road Not Taken: A World Where IPv4 Evolved

https://owl.billpg.com/ipv4x/
63•billpg•11h ago•127 comments

Full Spectrum and Infrared Photography

https://timstr.website/blog/fullspectrumphotography.html
51•alter_igel•4d ago•26 comments

Show HN: Understudy – Teach a desktop agent by demonstrating a task once

https://github.com/understudy-ai/understudy
92•bayes-song•10h ago•38 comments