Redis array: short story of a long development process

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aantirez about 4 hours ago 46 commentsRead Article on antirez.com

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Discussion (46 Comments)Read Original on HackerNews

tibbar•18 minutes ago

Reviewing 22,000 lines of code, even from antirez, with this complex of a feature set and minimal PR description sounds like a nightmare. One starts to see why major open-source software like Postgres tends to be developed on a mailing list, with intermediate design decisions discussed by the community, separate patches for different related features, incremental review, and then a spaced release cadence.

epolanski•4 minutes ago

Postgres and Redis are drammatically different projects.

Virtually all Redis features are a solo job of the post author.

The reviewers are paid for it by the way.

wood_spirit•about 2 hours ago

Sharing my current MO:

I start with a high level design md doc which an AI helps write. Then I ask another AI - whether the same model without the context, or another model - to critique it and spot bugs, gaps and omissions. It always finds obvious in hindsight stuff. So I ask it to summarize its findings and I paste that into the first AI and ask its opinions. We form an agreed change and make it and carry on this adversarial round robin until no model can suggest anything that seems weighty.

I then ask the AI to make a plan. And I round robin that through a bunch of AIs adversarially as well. In the end, the plan looks solid.

Then the end to end test cases plan and so on.

By the end of the first day or week or month - depending on the scale of the system - we are ready to code.

And as code gets made I paste that into other AIs with the spec and plan and ask them to spot bugs, omissions and gaps too and so on. Continually using other AI to check on the main one implementing.

And of course you have to go read the code because I have found it that AI misses polishes.

gen220•about 1 hour ago

The discourse around AI is that we’ve unlocked a whole new unsupervised paradigm of development; but you’re basically describing how Google has built code for a decade, just with humans of different levels of trust instead of AI.

And I’m not saying that to poke fun at you (my workflow is essentially identical to yours), or at Google, but rather to say that there’s nothing new :)

AI is a fantastic accelerator of effective and ineffective workflows alike. It’s showing us which are effective and ineffective on way shorter timescales / in realtime!

wood_spirit•26 minutes ago

That is actually reassuring. I used to try to work this way with people but the culture where I work didn’t align and I found it easier to work this way alone by trying to put myself into critique mode and so on. Now much better to get AIs to do it. And I find the more I polish the plan the less expensive the AI needed to implement too.

lovasoa•about 1 hour ago

How much faster/slower are you with that process compared to writing code yourself?

tracker1•43 minutes ago

Can't speak for GP or OP, but I see about 10x the output and 2-4x the value of what I would be able to get by hand. Within the gap between 2-4x and the 10x is really a lot of design documents, user/dev documentation and testing that I might not have rolled to nearly the extent that I do/get when using AI.

I haven't been using multiple AIs adversarially as OP, but might consider giving it a try with Codex and Opus. That said, my AI workflow has been pretty similar... lots of iterations on just design, then iterations on documentation, testing, etc... then iterations on implementation, testing, validation and human review in the mix.

My analogy is that it's really close to working with a foreign dev team, but your turnaround is in minutes instead of days, where it's much more interactive.

alfalfasprout•32 minutes ago

Having tried something similar, the perceived speedup does not, in the steady state, last.

To get a quality, lasting, result you're ultimately having to carefully study everything otherwise you end up quickly accumulating cognitive debt and the speedup soon shrinks as you're constantly having to revisit the initial approaches.

ericpauley•19 minutes ago

Couldn't some of the use cases presented for this be accomplished with ZSETs? I get the performance angle, but it seems that this could have been accomplished without the new API surface by selectively optimizing ZSET storage for dense values (in the same way that Arrays selectively use sparse representations).

The RE component is interesting, but as commentary here has noted it seems orthogonal to the array data structure (i.e., usable on others as well). Does this not make more sense to accomplish with Lua scripting? Or if performance of Lua is an issue perhaps abstracting OP to be composable on top of any command that returns a range of values.

I say this with reverence for Antirez as the expert in this space, but some of this new feature set feels like the sort of solution that I tend to see arise from LLM-driven development; namely creation of new functionality instead of enhancement of existing, plus overcomplicating features when composition with others might be more effective.

gurgeous•about 1 hour ago

Thanks for adding this. Excited about array/regex, also very interested in your experience using LLMs to stretch your abilities. There are many of us laboring quietly on various projects attempting the same. "Vibe coding" (and the backlash) doesn't really capture how we work.

tracker1•41 minutes ago

I definitely don't consider how I've used agents as vibe coding at all... I'm much too involved and validate/verify/review everything.

localhoster•about 2 hours ago

Let's make it very clear - this is the original creator of redis, or one of them.

He is not "your avg dev" and it took him 4 months with llm.

This is not a seal of approval for you to go and command all your developers to move to Claude code/codex/any other ai coding tool fully.

I'm looking at you - any avg CEO of a startup.

DrammBA•about 1 hour ago

> He is not "your avg dev" and it took him 4 months with llm.

To clarify, from TFA:

> even before LLMs the implementation was likely something I could do in four months. What changed is that in the same time span, I was able to do a lot more

The initial timeframe was 4 months, he was able to do more work within the same timeframe with LLMs.

tracker1•36 minutes ago

I would add that the output was likely more as well.. ex: more thorough tests, documentation, etc.

I've been working on a Database adapter for a couple months using an LLM... I've got a couple minor refactors to do still, then getting the "publish" to jsr/npm working... I've mostly held off as I haven't actually done a full review of the code... I've reviewed the tests, and confirmed they're working though. The hard part is there's some features I really want when in Windows to a Windows SQL Server instance that isn't available in linux/containers. I don't think I'll ever choose SQL again, but at least I can use/access a good API with windows direct auth and FILESTREAM access in Deno/Bun/Node.

FWIW: My final implementation landed on ODBC via rust+ffi so after I get the mssql driver out, I'll strip a few bits in a fork and publish a more generic odbc client adapter. using/dispose and async iterators as first class features in the driver.

simonw•about 2 hours ago

It's a pretty strong endorsement for the idea that coding agents, used skillfully by experienced developers, can further amplify their expertise.

slig•12 minutes ago

>He is not "your avg dev" and it took him 4 months with llm.

He's not, but his work is obviously not average.

Average dev work is plumbing and CRUDs.

thallavajhula•16 minutes ago

Salvatore really wants to popularize the term Automatic Programming/Coding it seems. (https://antirez.com/news/159)

SuperV1234•about 3 hours ago

Closely matches my own experiences with current SOTA AI. Extremely useful collaborator, far from being a replacement for human intelligence and creativity.

foobarian•about 3 hours ago

I like to say, AI is the duck programming duck I always wanted

bonesss•about 3 hours ago

LLMs are the insensitive Asmovian robots I’ve always wanted, who translate and do the hardest part of my job: ensuring my emails are polite and none of my true thoughts or feelings are revealed…

Now I just need a way to protect my chats from any potential discovery, and <pew pew> business’ll be easy.

genghisjahn•about 2 hours ago

I occasionally type into slack "Future lawyers, the previous conversation is a joke. No one is doing cocaine to get through writing requirements docs."

antirez•about 3 hours ago

There are projects that I develop mostly not looking at the code, but owning the concepts, algorithms and ideas asking questions and giving hints, and owning especially the product. But, not for Redis, not yet at least. When in the future this will be possible, server software, the way it is developed today, will be over. I bet there will be still projects and repositories, as accumulation of features, fixes and experiences will still be worth it, but the role of programmers will be very similar to what Linus did so far for the kernel. And for certain projects I'm developing, like the DeepSeek v4 inference engine, I'l already working like that.

sylvinus•about 1 hour ago

Thanks for the write up. Always interesting to see how very senior developers interact with AI these days.

@antirez: Introducing a regex feature that late into the project for a seemingly unrelated feature feels a bit weird? Can you explain more your rationale on that? thanks!

antirez•about 1 hour ago

Once I realized arrays were a great fit for text files, many use cases I could conceive were always limited by the fact we need to grep on files. So I thought: what is the AROP equivalent for files? ARGREP. Then I made sure to add both fast, exact and regexp matching so that depending on the use case the best tool could be used. I then discovered that for many OR-ed strings regexps could be the faster way if we'll optimized. And then I specialized TRE a bit.

simonw•43 minutes ago

Are there other existing Redis data types and features that might benefit from integrating TRE?

antirez•35 minutes ago

KEYS comes immediately to mind :)

nitwit005•32 minutes ago

The use of C stdlib localization functions (toupper, mbrtowc, etc), makes me suspect if there will be some regex behavior differences between systems or locales.

antirez•29 minutes ago

Redis sets the locale at startup to avoid issues so should be ok but we will document that for instance è will not match È when nocase is used.

jdw64•about 2 hours ago

It feels like Redis is becoming a small database, which seems to make it more convenient to use. Could you add more examples that clarify where the boundary should be?

antirez•about 2 hours ago

Well, Redis is a data structures server, and has very complicated and edgy data structures like the HyperLogLog, so I have very little doubts that a fundamental data type like the Array will fit :) Also the actual complexity added is mostly two C files that are quite commented and understandable.

    wc -l t_array.c sparsearray.c
        2012 t_array.c
        2063 sparsearray.c
        4075 total (including comments)

Sure there are also the AOF / RDB glues, the tests, the vendored TRE library for ARGREP. But all in all it's self contained complexity with little interactions with the rest of the server.

A quick note: if we focus only on that part of the implementation, skipping tests and persistence code which is not huge, 4075 lines in 4 months are an average of 33 lines per day, which is quite low.

jdw64•about 2 hours ago

I’m a big fan of your work, and I honestly didn’t expect to receive a reply from you. Thank you. Also, thank you for pointing out exactly where I was misunderstanding the issue. In the past, I used Redis for temperature measurements in a smart farm project. I used Hashes back then, but it seems like Array would fit that use case much better.

This looks like a very useful feature. Thank you again for the reply.

antirez•about 2 hours ago

I appreciate your kind reply as well :)

leetrout•about 2 hours ago

On safari mobile it's a page with the title header and a footer. Theres no content rendering.

antirez•about 2 hours ago

Checking, thanks. EDIT: works very well on my iPhone, so without being able to reproduce is not easy to fix.

tobr•about 2 hours ago

Same here, I need to turn off content blockers for the article content to load.

antirez•about 1 hour ago

I should probably remove the Adsense JS which I don't use anyway...

gbalduzzi•about 3 hours ago

Is it possible to see the specification file you created and used for AI assisted development?

Very cool anyway! Can I expect a youtube video about this soon?

antirez•about 3 hours ago

Yep I will release it, it is a bit out of sync at this point, but will do a pass of updating and will release it.

nojvek•30 minutes ago

It’s always a great HN thread when an author of a widely used lib/app engages on a technical level.

antirez - you inspire a generation of devs. Thanks for all you do.

ok123456•about 2 hours ago

Is this an apologia since the PR is +22,212 -34?

antirez•about 2 hours ago

Haha, ~5000 LOC with comments. The rest is tests + TRE code + TRE tests.

epolanski•about 1 hour ago

Got few questions:

- the project essentially spans almost 3 different (albeit minor) generations of LLMs. Have you noticed major differences in their personas, behavior, output for that specific use case?

- when using AI for feedback, have you ever considered giving it different "personalities"? I have few skills that role play as very different reviewers with their own different (by design conflicting) personalities. I found this to improve the output, but also to be extremely tiring and to often have high noise ratio.

- when did you, if ever, felt that AI was slowing you down massively compared to just doing it yourself (e.g. some specific bug or performance or design fix)? Are there recurring patterns?

- conversely, how often did AI had moments where it genuinely gave you feedback or ideas that would've not come to you?

- last: do you have specific prompts, skills, setups, etc to work on specific repositories?

dsecurity49•about 2 hours ago

AI is a fantastic co-pilot, but you still need to know how to fly the plane when the edge cases start hitting the fan.

simonw•about 1 hour ago

I vibe coded up an interactive playground against a WebAssembly build of the new array features: https://tools.simonwillison.net/redis-array