Pinned Tweet
hello world!
Introducing Formidable Builders @formidablebldrs
A community built by and for people who ship.
Because progress starts with work.
Permission comes later.
Two years ago, I unintentionally organized the first @euacc meetup, one week after @levelsio published the manifesto.
It began as a humble e/acc meetup for techno-optimists in Bucharest, inspired by @beffjezos. I wanted to meet people who believe that technology, ambition, and agency could build a better future, faster.
Since then, more than 300 people have joined our meetups and weekly coworking sessions. Our WhatsApp community has grown to over 150 builders.
They pushed me to look further, think bigger, and build something that exceeded all my expectations.
Today, eu/acc Romania becomes Formidable Builders.
This community belongs to the people who are part of it.
Because these people are formidable!
Meetup #5 is happening on Nov 4.
We’re continuing the Agentic Engineering series with Loops, graphs & workflows, hosted by @stripe at their Bucharest HQ.
On the menu:
• 2 rounds of live demos
• open mic
If you’ve got something cool to show, this is your sign 👇
Formidable Builders retweeted
Last weekend we built Ghostline (a system to detect humans through walls using Wi-Fi) at the European Defense Hackathon and got on the podium.
Today the paper is published on arXiv:
arxiv.org/abs/2610.18764
Congrats @le_alecs @IonutMoldovanuG @elitepax @andratrita
Formidable Builders retweeted
Everybody's showing off single user decode speed. Who cares ?
Agentic use is 128k+ context. Show me prefill @ 128k context. Show me decode speed @ 2-3 users for a 128k prompt.
Computing prefill attention= O(n2). Decode attn is O(m) and generating tokens with KV cache is O(nm + m2).
Decode speed for single-user simple prompts tell nothing and are misleading !
Historic moment for our community!
The Formidable Builders team returned home with the Bronze medal. 🥉
Third place at the @Eurodefensetech Bucharest Hackathon for @le_alecs , @IonutMoldovanuG , @cochinescu , @elitepax & @andratrita
part 2 from @Eurodefensetech Bucharest Hackathon
introducing @formidablebldrs team no 1
with @le_alecs @elitepax @cochinescu @IonutMoldovanuG
Formidable things are happening
Huge day. $200M Series B at a $3.1B valuation for @arena and the release of our Alignment Index. I am proud of this team for solving one of the hardest problems in AI: evaluating AI under real-world conditions.
We're still a small team, about 90 people, and we're hiring across ML, product, engineering, design, marketing, BD, and more. If evaluations, safety, and measuring progress interest you, check out the open roles in @arena's bio.
Formidable Builders retweeted
it's late 🥲
@Eurodefensetech Bucharest Hackathon 2026
@formidablebldrs team no 2 with a couple of guys that have no X (yet) and @iamrobertolariu, the man that hyped me into joining
part 2 from @Eurodefensetech Bucharest Hackathon
introducing @formidablebldrs team no 1
with @le_alecs @elitepax @cochinescu @IonutMoldovanuG
RT @gabimoncha: part 2 from @Eurodefensetech Bucbarest Hackathon
introducing @formidablebldrs teams no 1
with @le_alecs @elitepax @cochin…
This quoted post is unavailable.
Formidable Builders retweeted
Replying to @Eurodefensetech
@Eurodefensetech Bucharest Hackathon 2026
@formidablebldrs
To finish off our @how_to_web 's Demo Nights series, we interviewed our last founder. At first, we weren’t smart enough to understand what he was talking about, but hey, after all, that’s what these questions are for, right?
Here’s Dragos clearing things up!
We somehow managed to catch @how_to_web ’s Demo Nights winner between business meetings and discover what made him stand out.
Congrats @Mark_cldb !🏆
We all need to be recommended by someone in order to become successful, but when AI took over, suddenly things were a bit different, so we asked @iamrobertvija at @how_to_web ’s Demo Nights to tell us how his startup is solving this problem.
We all wish for world peace, but is it really possible anymore? Someone dared to dream big and showed us that we could be more than close to this goal!
Find out Mara’s idea at @how_to_web ’s Demo Nights!
Formidable Builders retweeted
Scoring for our @formidablebldrs GTM Skillathon ran on a skill I wrote: one subagent per submission, all 34 in parallel.
It spawned exactly one.
I noticed 15 minutes into a 20-minute window, typed the message below, and switched to low reasoning to catch up.
That caused a bigger problem. Will cover the consequences in a reply to this post.
Replying to @how_to_web
@how_to_web ’s Demo Nights wasn’t something we could miss. We just had to see what the founders were pitching.
So, we decided to ask each one of them some questions and find out!
Say hi to @vlad_fatu , our first victim.
Subscribe to our Luma calendar: lu.ma/formidablebuilders
Formidable Builders retweeted
Introducing Formidable Builders launch video - Opus 5.5 edition
I gave it access to @formidablebldrs folder and asked it to make an extraordinary video
It's interesting that i tried to improve it / reduce the slop but the outputs where more mid - so in the end I reverted to the initial video. Hope you enjoy it!
Introducing Formidable Builders @formidablebldrs
A community built by and for people who ship.
Because progress starts with work.
Permission comes later.
Two years ago, I unintentionally organized the first @euacc meetup, one week after @levelsio published the manifesto.
It began as a humble e/acc meetup for techno-optimists in Bucharest, inspired by @beffjezos. I wanted to meet people who believe that technology, ambition, and agency could build a better future, faster.
Since then, more than 300 people have joined our meetups and weekly coworking sessions. Our WhatsApp community has grown to over 150 builders.
They pushed me to look further, think bigger, and build something that exceeded all my expectations.
Today, eu/acc Romania becomes Formidable Builders.
This community belongs to the people who are part of it.
Because these people are formidable!
Formidable Builders retweeted
Opus 5.5 using strudel-cli to showcase strudel-cli
Help your new Opus 5.5 to make you new promo videos with the strudel-cli
github.com/TudorAndrei/strud…
Formidable Builders retweeted
Help your new Opus 5.5 to make you new promo videos with the strudel-cli
github.com/TudorAndrei/strud…
RT @gabimoncha: let's fucking go @flaviusburca 🔥🚀
oss jev you can host locally
This quoted post is unavailable.
Wrapping up our GTM Skillathon interviews by presenting @TheSergiu to you! Thank you all for participating! Can’t wait for the next one!












