Marceli Polubiec

@CodeWithTamara that’s cool!

I started coding at 37 after spending 10+ years in academia as a molecular biologist. By accident. No grand plan. No childhood prodigy story. Just curiosity, a laptop, and the extremely dangerous discovery that making computers do things is addictive 😊

@maniadhikarii Im looking for founders who want to share their experience, let’s talk

my circle on X is still small and i actually want to fix that. looking to connect with: founders building in public people shipping fast with AI designers who care about craft traders and investors anyone figuring it out as they go reply with what you're building or trading and let's connect 🙌

@YassineZaanouni @X let’s chat I need some real founders

Most of Twitter is noise. @X The fun part is finding people who actually build things. If you’re into -Tech -AI -Startups -Design -Web Dev -SaaS -Building in public say hi 👋 and let’s connect

day 5: building an AI agent that automatically sells your used stuff Sunday is a great day for progress 🚫 no phone calls 🚫 no meetings 🚫 no distractions I spent the whole day making a plan for the week ahead. let’s see how the execution goes

@borek_24 @listioapp dm me

i'm 15 and i've been working on my little project @listioapp for a while now. In short Listio is a tool that helps Vinted sellers sell more items in less time. So, take a photo of your product → AI writes a ready listing (title, description, hashtags), and then it also removes the background and replaces it with a professional one, so your listing can stand out. I'm going to update you everyday with my progress, so that i can be consistent Check @listioapp waitlist in comments

@0xrinx thanks. work in progress

@Marceli__P just post dialy. whatever you are doing

I joined 𝕏 1 year ago with no audience, no network, and no idea what would happen. 1 year later: • Earned money online using 𝕏 • Built a viral desktop app • Got paying users • Got selected for GSoC'26 • Connected with incredible people in tech • Made friends I will never forget The biggest gain wasn't the followers. It was the opportunity. Thank you, 𝕏

@Guronnimo Time. Scaling now so I can leave my second job and focus 100%

What's your current bottleneck? Building? Users? Revenue? Time?

@asaio87 Find cofounder

I talked to a vibe coder guy on Reddit today about his app. He launched his 10th app this year, but no customers. He spent millions of tokens on Claude Code He says he enjoys building the apps so much because he is using AI and can build so much faster. But when he needs to get users, feel discouraged and does the next best thing, starts another app, only to end up in the same place. What should he do ? Keep building until he hits a viral app that markets itself? or just continue with one app for 12 months and spend 9 hrs a day marketing it

day 4: building a platform that automatically sells used stuff online. throwback to the start. my first prototype used Telegram as the frontend and Make as the backend. no vibe coding yet, i just wanted a proof of concept. it was enough to get my first users, test the workflow, and find what needed fixing. it also gave me enough traction to convince a CTO to join. what did your first prototype look like?

@chams_builds thanks man! failing at startups is just the lesson most founders must learn. either its going to work this time or i try once again

@Marceli__P 5th startup and a first sale on day 1. you know the drill.

day 1: building an app that sells your used stuff for you. starting today im posting every day about building my 5th startup. mostly want to share the journey and meet some like minded people along the way. made my first sale today, so now's as good a time as any to start.

day 3: building an app that needs a name. how do you choose one? we know the basics: short, memorable, easy to pronounce. for the MVP I picked a name with no decent domain available (cared more about solving a real problem than a beautiful name) how did you land on yours?

@jm_martiinez Great ambition, good luck

i’m 22, from Uruguay, and i want to break into a top silicon valley startup. what’s the biggest thing standing between me and that goal? be brutally honest.

@_milosandric @Tancrededib I like it, where I can test your app

@Marceli__P @Tancrededib How would you scale app thats has 1m requests per second?

explain your startup to me like i'm 4 years old

@_milosandric @Tancrededib Can you drop a hard question your startup is helping to prepare for

@Tancrededib My startup helps people practice a little bit every day, so when someone asks them hard questions for a job, they do not feel scared. They feel ready.

@JunaidAckroyd let’s talk

Reply and I’ll follow you. I want to connect with ambitious people building something great.

@hariprasad_bg We’re started in B2C and now testing B2B so some parts are not perfectly thought through

@Marceli__P Why? 🫣

Everyone’s chasing $10k mrr. I’m just praying today's deploy doesn't break.

day 2: building an app that sells your used stuff for you. the platform is down. classic startup timing the moment something's working, something else breaks. fixing bugs and tightening the workflow so it holds up better next time. day 2 and already firefighting.