System Builders: The Deals Moving Tech From Tools to Operating Layers

Key deals of the week (December 15 - December 19 2025)

Mirelo: Owning the Missing Modality in Generative Video

Mirelo pulled in a $41M Seed round to tackle a problem most video AI platforms still sidestep: sound. The Tübingen-based startup is building foundation models purpose-built for audio in video, allowing creators to generate synchronized sound effects and ambient audio in seconds. The round was co-led by Index Ventures and a16z, with Atlantic.vc, TriplePoint Capital, and a dense roster of AI-native angels backing the bet (Transformer co-inventor Jakob Uszkoreit and leaders from OpenAI, Mistral, Hugging Face, Meta, and Revolut).

Founded in 2023 by CJ Simon-Gabriel and Florian Wenzel, Mirelo is using the capital to scale its core models, expand APIs, and push Mirelo Studio toward becoming a default audio layer for visual content. The conviction here isn’t about creator tools alone; it’s about owning a foundational modality. As video generation accelerates, whoever controls sound at the model level controls realism, emotion, and immersion. 

Leona Health: Turning WhatsApp Chaos Into Healthcare Infrastructure

Leona Health is tackling one of Latin America’s most entrenched healthcare bottlenecks: doctors drowning in WhatsApp. Built by former Uber Eats and Rappi operator Caroline Merin, the startup turns the region’s default patient communication channel into something physicians can actually manage. How it works: Leona plugs directly into WhatsApp but routes everything through an AI-powered mobile app that prioritizes urgent cases, suggests replies, and lets care teams respond without losing context or clinical records. The result is less chaos, fewer after-hours interruptions, and hours reclaimed each day for doctors who were previously expected to be always-on. Backed by a $14M seed round led by a16z with General Catalyst, Accel, and heavyweight operator angels, Leona is already live across 14 Latin American countries and 22 specialties. Now healthcare infrastructure doesn’t need to replace existing behavior to scale, it just needs to tame it. MyDello: Freight Forwarding Finally Gets a Software Spine

MyDello added fresh fuel to one of Europe’s quiet infrastructure upgrades. The Tallinn-based freight platform raised €3.1M to push beyond its current footprint, with the UK first on the expansion list. Led by Frumtak Ventures, with Superhero Capital doubling down and Bolt president Jevgeni Kabanov joining the board, the round backs a clear thesis: global logistics is still run on legacy workflows, and software-native freight forwarders are finally starting to win real share. MyDello isn’t pitching logistics “innovation”, but it’s systematizing pricing, routing, and execution in an industry where speed, transparency, and reliability have been missing for decades.

Lovable: When Creation Collapses to Intent

Lovable’s latest $330M Series B at a $6.6B valuation isn’t just an oversized AI round, it’s a stress test for how fast a product can scale when it collapses the distance between idea and execution. In less than a year since launch, the Stockholm-based startup has crossed $200M in ARR, with 100,000+ new projects spun up daily by users ranging from solo builders to teams at Klarna, Uber, and Zendesk. The appeal is straightforward: text prompts that turn intent into working software, without forcing users through the traditional coding funnel. CapitalG and Menlo Ventures are betting that this “vibe-coding” layer isn’t a novelty, but a new interface for software creation itself. 

With fresh capital earmarked for enterprise features, deeper integrations, and core infrastructure like hosting and payments, Lovable is positioning itself not as a full-stack environment where applications are conceived, built, and shipped at machine speed.

Coursera × Udemy: EdTech Consolidates as Skills Become Systemic

Coursera’s $2.5B all-stock acquisition of Udemy reads less like a power move and more like an acknowledgment of reality: standalone scale is no longer optional in online learning. Both companies were growing revenues yet watching public-market confidence erode. Content libraries and user growth alone aren’t enough anymore. By merging, they’re pooling complementary strengths: Coursera’s institutional and credentialed learning footprint with Udemy’s massive creator-driven marketplace, to stabilize margins, defend relevance, and reframe the category around workforce transformation. AI is the obvious accelerant here: microlearning, personalization, and skills mapping are moving from “nice to have” to table stakes as employers hard-require AI literacy. This deal is a bet that the next phase of edtech winners won’t just distribute content, but operate as adaptive skill infrastructure for a labor market being reshaped in real time. Across very different markets the pattern is consistent: companies absorbing structural friction that entire industries have learned to tolerate. Audio that makes synthetic video believable. Communication rails doctors already use, made operational. Freight pricing that behaves like software, not negotiation. Code creation abstracted to intent. Learning platforms repositioned as workforce infrastructure rather than content libraries. Capital is flowing toward businesses that don’t sit on top of workflows but replace the brittle layers underneath them. In each case, scale comes not from novelty, but from inevitability: once the underlying system works better, reverting stops making sense. That’s where durable value is being built right now: quietly, foundationally, and with very little patience for legacy constraints.