Accelerators don’t build startups — Founders do: Lessons from the inside Define accelerator

By the CEO of BattleBoxes

Participating in a defense tech accelerator can be transformative if approached with the right attitude and full commitment. The value isn’t automatic  — it’s unlocked through intention, networking, disciplined execution, and honesty with peers and mentors.

If done right, it can be a focused sprint designed to push you, your team, and your communication to new levels. Looking back on the past three months BattleBox spent in the Define Accelerator, I’ve compiled and distilled five key lessons that any founder can apply – whether you’re in defense tech or another deep-tech field.

Commit fully: “In for a penny, in for a pound”

When you’re accepted into an accelerator, it’s tempting to carve out just the minimum time needed – attend the workshops, check the boxes, and keep your head down on core product work. But I quickly discovered that the magic happens when you dive deeper. Unplanned hallway conversations with mentors, impromptu office hours with domain experts, and even casual chats over coffee all led to breakthroughs in how I explain our value proposition, refine our technical roadmap, or spot potential pitfalls. Those extra minutes  — sometimes hours — are never wasted. Don’t half-ass it.

Vulnerability builds trust

It turns out that everyone else in the room — no matter how polished their pitch deck looks — is wrestling with the same uncertainties: product–market fit, technical feasibility, and — if you’re in defense tech — regulatory hurdles. Admitting where you’re stuck, whether on a core feature or go-to-market strategy, opens the door for peer feedback and mutual support. I was surprised by how willing other founders were to share their experiences, suggest workarounds, or simply lend an empathetic ear. Being open about challenges doesn’t make you look weak; it shows you’re serious about solving problems — and it forges stronger bonds within your cohort.

Every conversation counts

Accelerators don’t just plug you into mentors; they connect you to a wider circle — other investors, potential customers, regulatory bodies, and even defense end-users. Every conversation is an opportunity to gain fresh perspectives. Some advice may seem off-base — maybe a mentor suggests pivoting to a market you hadn’t considered, or challenges a core assumption you hold dear. Instead of dismissing it outright, I learned to listen first, probe the reasoning, and extract the kernels of insight. Even “wrong” advice can highlight blind spots you didn’t know existed.

Don’t rely on an accelerator to do the work for you

An accelerator is a springboard, not a substitute for your daily grind. It won’t magically solve every challenge or replace the discipline you’ve built into your company’s routine. While the program provides structure, feedback, and occasional shortcuts, it’s still on you to execute. Keep your regular sprint cadences, maintain stakeholder communication, and continue hitting your product milestones. You should integrate the accelerator’s resources into the work you’re already doing — not treat the accelerator as a separate, distracting side project.

Help others, grow together

Even in a defense tech program — where budgets are tight and success stories are coveted — the accelerator environment isn’t a zero-sum game. The chances that two startups will be vying for identical contracts or funding rounds are slim. More often, opportunities arise to partner on joint proposals, co-develop standards, or introduce each other to complementary networks. By helping others — making introductions, sharing technical notes, or co-hosting a workshop — you build goodwill, and more often than not, the karma comes back around to you.

Final words (of wisdom)

Joining Define was a rewarding experience. By committing fully, being open about weaknesses, tapping into every corner of the network, owning our roadmap, and collaborating with peers, we not only accelerated our product development but also strengthened our team’s resilience and vision.

On top of that, we wrapped up our journey by pitching at two separate Demo Days — one in Riihimäki, in front of industry professionals including the Finnish Defence Forces, the Finnish National Defence University, local investors, and specialists. The other opportunity will arise at Arctic15, a technology conference where we will have the opportunity to meet international VCs and investors.

If you’re about to start an accelerator program, remember: it’s what you make of it. Dive in, stay curious, and don’t hold back.

About BattleBoxes

BattleBoxes offers smart resupply for the decentralized battlefield. BattleBoxes are safe, secure, and field-deployable mini storages — giving the right gear to the right unit, at the right place and time, now with Tactical Integrity.