Real-Time-Bidding Engineer at Publicit Global · Barcelona

About Publicit

Be everywhere. Publicit is the European self-service platform for omnichannel advertising: one dashboard that puts a campaign on connected TV, billboards, digital screens in the street, metro stations, mobile apps and press. Things that used to take three agencies and six weeks now take a few minutes and a work email.

Underneath that simple dashboard sits the hard part, our own hybrid ad exchange. Every time an ad slot opens anywhere in our network, a TV in a living room or a screen in a metro corridor, an auction has to run and finish before anyone notices it happened. Milliseconds. Not "fast for a web app" milliseconds; the kind where garbage collection pauses are a bug, and where a query to a database you didn't need to make is the difference between winning and losing.

Most of the industry solved this by stacking more cloud servers on the problem and accepting the latency. We took the opposite bet: rebuild the decision path from the ground up, in Rust, with hardware acceleration and GPU-based decisioning, so we can afford to actually think about each auction. Is this ad relevant to this viewer? Is this placement safe for this brand? What is it genuinely worth? All of it in the time most exchanges spend on network overhead alone.

We're a small engineering team in Barcelona building real infrastructure in a market where most players stopped building years ago. Nobody here is maintaining someone else's platform.

The role

This is an engineering role with no walls around it.

In your first months you might write Rust in the auction path, build a screen in the dashboard that an advertiser uses that same week, chase down why two systems disagree about how much money was spent yesterday, and read an industry spec closely enough to argue with a partner's integration team about it. We're too small for you to only do one of those, and that's the point of joining now. You get to find out which one you're great at.

You will not be handed tickets. You'll be handed problems, context, and someone senior to ask when you're stuck. What you build goes to production, usually the same week.

You do not need advertising-technology experience. Almost nobody has it. It isn't taught anywhere and we all learned it on the job. What you need is to be the kind of person who reads the spec, opens the profiler, and figures it out.

What you'll do

• Ship across the stack. Rust in the systems that run the auctions, TypeScript and React in the product advertisers actually touch. You'll move between them week to week.
• Work where milliseconds are the product. Find out why something got slower, prove it with data instead of guesses, and make it fast again. Very few engineering jobs let you develop this instinct properly. This one does.
• Build the pipelines that make the money real. Billions of events a day turn into what an advertiser sees on their invoice. When those numbers are wrong, revenue is wrong, and you'll be the one who notices first.
• Implement the open protocols the industry runs on (OpenRTB, VAST, IAB consent frameworks). Reading specs carefully is a core skill here, not a chore.
• Own integrations end to end. Take a partner from first call to live traffic: schema, testing, and debugging their edge cases at twice the volume anyone predicted.
• Instrument everything. If a system is running in production and you can't see what it's doing, it isn't finished.

What we're looking for

• Around 1 to 2 years of hands-on engineering, internships included. We care about what you've built, not what your CV is titled.
• You've built something on your own. A side project, a tool that scratched your own itch, an open-source contribution, something you shipped at 2am because you wanted it to exist. Send it to us. This is the single thing that most affects whether we reply.
• Solid fundamentals in a systems language (Rust, Go, C++, or Java/C# with a real understanding of memory and concurrency), or clear evidence you'll pick Rust up fast. Nobody arrives fluent in Rust. We care that you can get there.
• Comfortable in TypeScript and React. Half of this job is product surface.
• You debug from first principles. Given a system you've never seen, you form a hypothesis, instrument it, and narrow it down, rather than changing lines until the error goes away.
• You write English well enough to argue in it. Our code, docs and partner conversations are all in English.
• You want to be in the room. This role is on-site in Barcelona. Early-stage engineering happens at a whiteboard with three people around it.

Bonus points

• You've worked, studied or lived abroad, or in a team spread across countries. Our partners, our inventory and our roadmap are European and you'll feel it from week one.
• You've touched low-latency, high-throughput or real-time systems anywhere: trading, game backends, streaming, telemetry, robotics.
• You've run something in production yourself: containers, infrastructure-as-code, CI you actually maintained.
• You've worked with high-volume data systems, whether streaming, analytical databases or in-memory stores.
• You know what a DSP, an SSP or a VAST tag is. Genuinely optional; we'll teach you.
• Competitive programming, hardware hacking, demoscene, emulators, anything where the constraint was the interesting part.

How we hire

1. Application. CV plus a link to something you built: GitHub, a live URL, a demo video, a write-up. Two lines on what it does and what was hard about it.
2. Intro call (30 min). Us, you, mutual honesty about what this job actually is.
3. Technical conversation (60 min). We walk through your project, then look at a real problem from our codebase together. No whiteboard trivia, no algorithm theatre.
4. Practical exercise. A small, paid, time-boxed task that resembles real work here.
5. Founders' conversation. Where we're going, where you fit, and your questions.

We aim to close the whole process within two weeks.

Why join

• Real infrastructure, not a wrapper around someone else's API. Low-latency distributed systems, hardware acceleration, GPU-based decisioning. That experience is scarce, and it compounds for the rest of your career.
• Ownership from day one. You'll own systems rather than tickets, far earlier than you would anywhere larger.
• Learn from people who've built this before. Direct access to the founders and to senior engineers who will read your code carefully, which is the fastest way anyone has ever gotten better at this.
• Competitive salary and equity. You share in what you help build.
• Barcelona. A team that works hard in the same room, and then goes and has lunch like human beings.

How we work

Extreme ownership. If something is broken, it's yours, regardless of whose job it was. We don't wait for someone else to pick up a dropped ball. We pick it up, then fix the process that dropped it.

Craftsmanship. "It works" isn't the bar. Details compound: a clean interface, a well-named metric, a doc someone can actually follow. We build things we'd be happy to have read back to us in a year.

Speed with direction. Time is the only resource we can't buy more of. We move fast, but we choose ruthlessly what to move fast on. Speed without focus is just noise.

Talent density. Every hire should raise the average. We reward contribution over tenure and give ownership to whoever earns it. Strong engineers want to work with strong engineers; that's the whole flywheel.

First principles. Advertising technology is full of things that are true only because they've always been done that way. We strip problems back to what's actually required and rebuild from there. It's the only reason a team our size can outbuild incumbents.

Be a good human. Direct, honest, kind. We give hard feedback with respect and celebrate wins without ego. We're doing something difficult, and it's better in good company.

Apply

Send your CV and a link to something you've built to [careers@publicit.es], or apply through the link on this posting.

Data protection

The personal data provided in your application and during the selection process will be processed by Publicit Global SL, acting as Data Controller.

By sending us your CV, you consent to the processing of your personal data for the purpose of evaluating and selecting you as a candidate for this position. Your personal data will be treated confidentially and will only be used for the recruitment process of the selected job offer.

Your personal data will be deleted after three months of inactivity, in compliance with the GDPR and applicable data protection legislation.

To exercise your rights of access, rectification, deletion, portability or objection in relation to your personal data, you can contact legal@publicit.es , subject to the GDPR.

For more information, visit [https://publicit.com/privacy-policy].

By submitting your application, you confirm that you have read and understood this clause and that you agree to the processing of your personal data as described.