Boosting startups in Green & Digital

About the program

Challenger is a non-equity startup accelerator based in Bratislava. Every year we select a batch of 8 to 10 early-stage startups to participate in a 3-month program. We help you find product-market fit, paying customers, and raise investment to scale your operation.

In the following batch, we are looking for startups solving challenges in cleantech, mobility, circular economy, agritech, e-commerce or digital transformation, and other fields contributing to sustainable development.

What We Offer

4k - 10k EUR grant

for the company´s development during the program

Personalized growth plan

Tailored one-on-one mentoring and business coaching approach

Mentoring & Coaching

Individual coaching with international mentors

Demo Day

Presentation in front of investors, customers, and partners

Investor matchmaking

Access to the most prominent investors in Europe

Customers & Industry experts

Market validation by industry experts and access to potential clients and partners

Program outline

The program is adapted to meet the needs of today’s startups and apart from intensive mentoring also offers implementation time.

Applications Open

1st August

Apply to the accelerator by submitting a short application form via F6S (hyperlink:


6th September

Meet the Challenger team and learn more about our approach and mentors.

Applications deadline

9th September

Make sure you submit your application by Thursday, 23:59 CET. You will learn the next day if you are shortlisted and invited to attend the Selection Bootcamp.

Selection Bootcamp

15th September

During this all-day event you will meet mentors, coaches, pitch your business. Top 8-10 startups will make it to the program. During the day, our mentors and jury will select the top 8 startups to participate in the accelerator. You will learn the results at the end of the day.

The acceleration program

16th September - 16th December

The program starts with an individual assessment of each startup. Together with your coach and mentors, you will prepare a roadmap for the next 3 months. Every week you will have workshops, individual mentoring sessions, and investor & industry events that are designed to accelerate your business.

International Bootcamp

16th September

The accelerator starts with a full-day international Bootcamp, where you will meet top startups and mentors from other countries.

International Presentation Day

15th November

This is the first time you will pitch your business and progress made to the public and the jury of investors.

Demo Day

16th December

This is the final event of the Challenger accelerator. You will have 4 minutes to pitch your startup to the jury of international investors, potential clients, partners, and the media. The experience from the startups from our previous programs confirms that the Demo day helps startups to stand out and find key investors, partners, clients for the future.

We are looking for you

In this batch, we are looking for startups solving challenges in cleantech, mobility, circular economy, agritech, and other fields contributing to sustainable development.

Early stage technology startups with sustainability solutions from Central Europe

Functional prototype with proven traction

Strong team conscious of sustainable development challenges

Full-time commitment to participate in the program in Bratislava


Peter Gazik

O2 Slovakia

Boris Zeleny

Serial Entrepreneur and Investor

Andrea Basilova


Katarina Mihalikova

Majerník & Miháliková

Klaudia Bednarova

Executive Director & English Coach
The Bridge

Jan Cifra


Howard Kingston

Escape Velocity

Dalibor Pulkert


Christa Bleyleben

Managing Partner
MassGlobal Partners

Lia Alvarez

Founder & CEO
Fair by Nature

Anton Zajac

Eset North America

Simon Sicko

Pixel Federation

Mary Macpherson

Slovak American Foundation

Matej Ftacnik


Iurii Blavt

Associate Partner

Harri Tallinn

Team Lead

Jaroslav Luptak

Managing Partner
Neulogy Ventures

Vytautas Cerniauskas

Startup Mentor

Peter Simko


Lucia Sickova

Pixel Federation

Martin Santa

Story teller

Michal Nespor


Daniel Gaspar

Managing Partner

Miska Krskova

Startup Advisor

Viktor Mikulasek


David Szedely

Investment Manager
Neulogy VC

Andrej Petrus

Investment Manager

Martin Basila


Michal Hrabovec

Founder and President

Martin Mastalir

Area Manager
Cisco System

Conor Clifford

Investment Principal

Jan Porvaznik

Energy Storage

Frequently Asked Questions

The program targets start-ups in the early stage but already with at least MVP and some traction. The goal is to help you build traction, prepare you for serious investment, and connect you with the right people. We work closely not only with VCs and business angels but also with corporate partners and public authorities.

Challenger Accelerator takes place in Bratislava. Some of our workshops and mentoring happens online and some physical events and meetings take place in our office at the Spot or other places in the city center. No one knows what the situation with Covid-19 will be like in the fall, but we are ready for all scenarios. We have good experience in running acceleration programs fully online, in-person, or hybrid. Our priority is to have as much of the program in-person but will look closely at the pandemic situation, and change to online whenever needed.

We do not invest in startups directly, but we connect you with investors. The winner of our program can negotiate an investment of at least 250,000 EUR through our investment partner Crowdberry. We have a strong track record of connecting start-ups with the right people and receiving the investment is all up to your skills and the company potential. Over the last years, the startups that participated in our acceleration program raised more than 700 mil EUR in external funding! On top of that, we give all startups a development grant of 4,000 – 10,000 EUR to be used during the program.

The program requires around 8-10 hours commitment per week in Bratislava for 1-2 co-founders/startup executives. During a typical week, you will have a 4-hour group session on Tuesday afternoon covering the most essential topics. Wednesdays are dedicated to individual mentoring and coaching. On Wednesdays, we also organize networking events, inspiration talks by successful entrepreneurs or investors, and other special workshops. Some individual mentoring sessions can also take place during other days of the week, or even virtually, based on the availability of mentors and startups. Due to the pandemic situation, the program and format of Challenger can change, but the time commitment will remain similar.

At least one co-founder/executive should be present at each session. It does not have to be the same person each week.

You need to submit your application via the F6S platform ( by 9th September. The answers provided in the application form should provide a convincing case on why the company should be selected for the program. On the 10th of September, the best startups will be shortlisted for an all-day selection Bootcamp which will take place on the 15th of September 2021. Following the pitching and Q&As, the selection committee will select the batch of 8 – 10 companies which will participate in the program.

You need to have an MVP with traction, potential customers, or subscribers. We look closely on the innovativeness of the product, market potential, and team.

Then unfortunately you are not the right fit for the program. However, we have different programs to support entrepreneurs at all levels. If you want to know more send us info at

Only you can make your business succeed. But we can promise to push you for real results and tough love to get you closer to your goals. You can also expect new connections, feedback, and knowledge. You’ll get it in different formats: 1-1 mentoring with experts, business coaching, networking events, business workshops. We’ll help to develop your own customized plan and will make sure you’ll get the most out of the program.

Active participation, hard work, and dedication. Throughout the program, we’ll constantly evaluate your progress. If it will seem that there isn’t a mutual fit in the expectations and outcomes, we’ll need to say farewell to each other even before the final demo day.

Our focus is on Green & Digital. We are looking for the next Steve Jobs in clean-tech, climate-tech, green energy, smart mobility, circular economy, smart city, e-commerce, food tech, or digital transformation. If you don’t fit in any of the categories, you can still send us your application. We closely evaluate each start-up and can make the exception in specific cases.

Yes. However, the limit for the funding is 500 000 EUR.

If you have any other questions, please, feel free to reach out to us at

Unicorn Partner

Growth Partners

Seed Partners

Investment Partners

In cooperation with


Powered by