Line Rindvig, CEO of Defense Builder

For nearly three years, the Ukrainian defense startup accelerator Defense Builder has been helping the country's defenders gain access to the most innovative and original technologies developed by emerging startups that are still relatively unknown.

Since September 2025, Defence Builder has been led by Danish executive Line Rindvig. After Russia's full-scale invasion began, she realized she could not stand aside and became actively involved in volunteer efforts in Ukraine. She worked on logistics, coordinated humanitarian and military aid, developed strategic partnerships, and led advocacy initiatives aimed at raising international awareness of Ukraine's defense needs.

Ukrinform spoke with Rindvig about which unmanned technologies are likely to be most relevant on the battlefield in the coming months, the contribution small companies are making to their development, and how the accelerator helps ensure that cutting-edge technologies reach Ukrainian defenders as quickly as possible.

OUR TASK IS NOT JUST TO TEACH STARTUPS HOW TO ATTRACT INVESTORS

- How is the war in Ukraine shaping the way your company develops defense technologies and responds to battlefield needs?

- We were created because of the war. We are a Ukrainian company founded by the Kyiv School of Economics, Sigma Software, and Buntar Aerospace. Buntar Aerospace is a Ukrainian defense drone manufacturer. At an early stage, they realized that many companies were failing because they could not secure funding, struggled to source components, and generally found it difficult to build a company.

As a result, Buntar Aerospace decided to support early-stage defense technology startups. They joined forces with the Kyiv School of Economics and Sigma Software to establish the Defense Builder Accelerator.

Our work revolves around close cooperation with the Armed Forces of Ukraine. Almost every week, we communicate with different military units—corps, individual soldiers, battalions, border guards, the National Guard, and special operations forces. We analyze trends emerging from military laboratories, identify technologies that are still needed, and determine which components should be replaced.

As an accelerator, we then search the market for solutions that can ultimately reach the hands of Ukraine’s defenders. Once we identify promising technologies, we select companies, conduct interviews, and admit them into our four-month acceleration program.

It is a highly advanced program. Today, defense companies are expected to meet extraordinary demands: the government and defense forces require rapid production, reliable supply chains, and the ability to manufacture hundreds of drones. These are enormous expectations for newly established companies.

Our role as an accelerator is to connect them with experts from military institutions to provide feedback and improve the technical aspects of their products. In many cases, however, these are not yet companies—they are merely ideas. Therefore, we teach founders how to properly structure a business, become attractive to investors, understand intellectual property and export control regulations, and prepare for future NATO certification requirements from the earliest stages.

Our mission is not simply to help them raise investment. We have adapted the program to the realities of wartime: rapid development, rapid production, and surviving under extremely demanding conditions.

TECHNOLOGIES THAT WILL BE IN DEMAND OVER THE NEXT SIX MONTHS

- How many companies have you supported so far?

- We were founded in 2024 and have been operating ever since. We have already supported 15 companies, while another nine are currently completing our program and will graduate at the end of June. The combined valuation of companies from our first two cohorts has exceeded $100 million.

For the third accelerator cohort, teams were selected based on technologies expected to become critically important on the battlefield within the next six months.

The third cohort includes the following teams:

Trident Group addresses the vulnerability caused by navigation loss. In modern warfare, GPS can no longer be relied upon because electronic warfare has turned navigation into one of the weakest points of unmanned systems. Even the most advanced drone may lose orientation in the final seconds before striking its target.

Their approach is based on autonomy. The system uses computer vision and guidance algorithms that allow the aircraft to complete its mission even when communication with the operator is limited or entirely unavailable.

Frost Works offers a UAV detection system combining acoustic and radar sensors working in coordination. It enables detection of low-altitude aerial threats, including Shahed-type drones flying close to terrain contours.

Fremen has developed a device designed to protect expensive reconnaissance drones from interceptor drones. As reconnaissance UAVs are increasingly destroyed by inexpensive interceptors, Fremen offers an onboard module weighing less than one kilogram that continuously scans the surrounding airspace, detects approaching threats, and actively helps neutralize them.

WingTech develops and manufactures fixed-wing UAVs for strike and logistics missions at medium ranges.

Their UAV, HABA, is capable of delivering high-precision strikes over long distances despite GPS denial and intensive electronic warfare. It can take off and navigate without GPS using proprietary inertial systems and radio beacon navigation. Automatic landing without a parachute enables repeated combat use and rapid redeployment.

This type of drone is currently in high demand among Ukraine’s Security and Defense Forces for disrupting enemy logistics routes.

Today, FPV drones account for 70–80% of battlefield casualties. Traditional electronic warfare systems are becoming less effective due to frequency hopping, fiber-optic control, waypoint navigation, and AI-guided targeting.

The NEBOSTRAZH system addresses this challenge through automated counter-drone operations. Cameras, algorithms, and a turret function as a unified system, seamlessly transitioning from detection to tracking and finally to engagement.

The developers created an autonomous AI-powered anti-drone defense system combining the SM-1 multisensor mobile turret with an FPV interceptor drone, both controlled by a unified artificial intelligence platform. The AI is trained on a unique dataset of Ukrainian combat footage collected over years from multiple verified sources and reflects real battlefield conditions and threat categories.

Another challenge is Shahed drones approaching Ukraine over the sea.

BlueShadow focuses specifically on countering this threat by acting as the chief integrator and intelligence layer coordinating swarms of unmanned surface vessels. These systems autonomously detect, track, and intercept incoming strike drones before they reach the coastline.

Telearmy offers remote-control technology for military vehicles without requiring complete redesign of existing platforms. Instead of waiting years for next-generation systems, Telearmy upgrades equipment already in service, effectively transforming almost any vehicle into an unmanned platform.

The past year has also seen rapid development of unmanned ground vehicles. Delivering ammunition or evacuating wounded personnel can sometimes be more difficult than conducting combat operations themselves.

Taurex represents an engineering response to this challenge. Its articulated frame maintains continuous ground contact, allowing movement across terrain where conventional vehicles lose traction or overturn. The platform can transport over 300 kilograms with a range exceeding 80 kilometers on a single charge. Its off-road capability is enhanced by airless tires and satellite communications for control.

UNMANNED GROUND PLATFORMS ARE BECOMING A MAJOR BATTLEFIELD TREND

- Do you work only with Ukrainian projects?

- They are primarily Ukrainian companies, although we also have several European participants. We welcome European solutions only when equivalent capabilities do not yet exist in Ukraine.

If Europe has technologies that are needed on the front line or battlefield in Ukraine, we help accelerate their development and integrate them into the feedback cycle with the Armed Forces.

In that sense, we were truly born out of war—that is how the war shaped our organization.

- You mentioned European partners. Which countries are we talking about?

- Estonia and Denmark.

- What exactly, if it's not a secret, technologies are they working on?

- One company develops dual-use technology for remotely operated armored vehicles. Ukraine still has thousands of armored vehicles in service, and although they are used less frequently on the front line because both sides have learned to counter them, there remains a large fleet of pickups, medical vehicles, and other transport.

Unmanned ground platforms are becoming a major battlefield trend, so the idea is to convert armored vehicles into remotely controlled systems to save lives.

The Danish company specializes in coastal detection and protection systems. For example, drones launched from Crimea need to be detected over the sea and intercepted before reaching land. Their solution focuses on early detection and maritime interception.

COOPERATION BETWEEN UKRAINIAN AND EUROPEAN DEFENSE MANUFACTURERS IS CRITICALLY IMPORTANT FOR BOTH SIDES

- How important is cooperation between European and Ukrainian defense companies?

- It is critically important for both sides.

Ukrainian companies gain opportunities to establish joint ventures with European partners, scale production in safer environments, and access broader supply chains.

European companies, meanwhile, can test their solutions in Ukraine, receive real combat feedback, and understand what it means to build defense technologies that must perform against a real adversary.

Europe has much to learn from Ukraine, particularly how to create highly effective solutions with significantly smaller budgets.

I am often surprised that European startups at the same stage raise three to five times more funding without producing better results. The reason is simple: Europe operates in peacetime, while in Ukraine this is not about profit—it is about survival.

I have a deeply moving message from one Ukrainian founder who told me: “I was in Bucha. I saw what happened there. I saw what my daughter witnessed. I do not want anyone else to experience that. I am not doing this for money—I want to build the most effective weapons possible to stop the enemy.”

That is the fundamental difference: for most Ukrainians, this is about survival, not business.

- What role will Ukraine play in the European defense market after the war?

- Ukraine is the only country—including both its industry and its defenders—that fully understands the enemy.

Therefore, Ukraine will play an enormous role not only in sharing lessons learned and expertise but also in anticipating the enemy’s next moves. We must think strategically and long-term, and Europe will rely heavily on Ukraine in this regard.

- Line, how and why did you start doing what you do?

- I have always been interested in geopolitics. As a teenager, I wanted to join the Danish Air Force, but instead I chose music and spent 18 years working in the music industry.

When Russia launched its full-scale invasion, I could not simply watch from the sidelines. I searched Instagram for people in Kyiv and reached out to activists and defenders asking, “How can I help?” That marked the beginning of my volunteer work and many important new connections.

In 2024, I decided to completely change my career and made the transition.

I have never been prouder of Denmark than when I witnessed its support for Ukraine—providing artillery, advocating for F-16 fighter jets, and standing with the country. I want more young Europeans to do the same. Even if Ukraine does not personally concern them, they should think about their own future.

Olga Tanasiychuk, Prague

Photo credit: Olga Tanasiychuk