Defence Builder accelerator expands into ecosystem with $5M venture fund

The founders of the Defence Builder accelerator — Sigma Software Labs, KSE, and Buntar Aerospace — announced the expansion of the initiative. Defence Builder is becoming a defence tech ecosystem which, in addition to the accelerator programme, will include the DB Fund venture arm, as well as market analytics, deal support, due diligence, and corporate governance services. The ecosystem is headed by Daria Yaniieva, investment director at Sigma Software Labs.

The DB Fund totals $5 million. It already invests in defence and dual-use companies at early stages, from pre-seed to Series A, with tickets of up to $300,000. The fund currently has four portfolio companies: Sine Engineering (communications and navigation), Falcons (electronic warfare and control systems), MaXon Systems (interception systems), and Huless (unmanned communication solutions).

In the near term, the fund team plans to close several additional deals. Within the Defence Builder ecosystem, there are also plans to launch a second, larger investment fund within the next year.

In addition to the venture arm, the Defence Builder ecosystem now includes deal support (including market entry, partnership structuring, M&A, and joint ventures), defence-specific due diligence, and the development of corporate governance in line with international institutional investor standards.

Another area of the ecosystem is sectoral analytics, which Defence Builder is developing jointly with KSE Institute. The research will cover the structure and dynamics of Ukraine’s defence tech market, key technology segments, and the investment landscape, including investor behaviour and funding models.

Sigma Software, KSE, and Buntar Aerospace founded the Defence Builder accelerator in 2024. The team has already run two cohorts, with the third currently underway. In total, more than 25 companies have participated in the programme, with an average product readiness level of TRL 6–7. According to Defence Builder, the combined valuation of companies from the first two batches exceeds $40 million, and some teams managed to raise funding within the first year after completing the programme.

The Defence Builder ecosystem believes that combining an accelerator, a venture fund, and additional support functions will allow companies to move through the entire lifecycle within a single system — from initial selection and product validation to investment readiness, due diligence, deal structuring, and scaling strategy.