E.ON — Virtual Power Plant

Energy · Germany, UK, Netherlands, Sweden · 12 years

The problem. E.ON needed to dispatch heterogeneous energy assets — wind turbines, solar farms, CHPs, battery storage — across four countries in real time. TSO ancillary service participation (aFRR in Germany) meant the system had to be continuously available: an individual failure lasting more than 30 seconds was unacceptable. And the scope kept growing. Trading across Intraday, Day Ahead, Wholesale, and TSO ancillary markets simultaneously. 2GW of new capacity to connect. 400 assets to dispatch at peak.

What we built. A microservices platform on Scala and Akka, backed by Lightbend's production stack, running in a high-availability cross-datacenter configuration with Docker and Consul. Soft real-time operating capabilities. Architecture designed to hold up under TSO-grade scrutiny — not just at launch, but continuously, across regulatory regimes in four countries.

The result. 99.99% uptime per annum. Individual failures under 30 seconds. In 2025, we connected close to 2GW of new installed capacity. At peak: 400MW CHP dispatched simultaneously alongside wind, solar, and battery assets across live markets.

The same core team — Eloquentix engineers — has been in this codebase for 12 years. That continuity is not incidental. It is the reason the system is what it is.

Sonnen → Shell — Battery Storage Platform

Energy · Germany, US · 6 years · Through Shell acquisition

The problem. Sonnen needed two things at once: a residential battery management system and an energy contract fulfillment engine. The contracts were complex — multiple dimensions, variable rates, regulatory overlays — and off-the-shelf billing SaaS couldn't handle the calculation logic. At the same time, Sonnen was on a trajectory from AWS serverless startup toward ISO-compliant enterprise. Shell's acquisition accelerated that trajectory considerably.

What we built. The battery management platform and a custom contract calculation engine: every contract dimension calculated internally, then fed into the billing SaaS. We also helped architect and execute the migration from startup infrastructure to ISO-compliant enterprise — building toward the scrutiny that comes with being a Shell subsidiary rather than retreating from it.

The result. A platform that survived acquisition and came out the other side ISO-compliant and production-grade. Systems built to hold up under Shell-level infrastructure review — and they did.

They don't just execute on tickets — they advocate for the product, challenge our assumptions, care deeply about the long-term health of our tech and they thrive when things get complicated. They operate with the ownership of an internal team. For any organization looking for a true engineering partner, Eloquentix is the gold standard. — Stephan Lindauer, Senior Director VPP Technology, Sonnen

Shoeboxed — 20x Growth Since 2008

SaaS · Durham, NC · 15+ years

The problem. A startup scaling through every growth stage — from a few thousand users to over 800,000 businesses — accumulates technical debt, architectural decisions that made sense at one scale and don't at the next, and moments where the platform simply breaks under load. You need engineers who understand where the bodies are buried, because they were there when the decisions were made.

What we built. Shoeboxed's receipt, business card, and document management platform — continuously, since 2008. Not a project. Not a sprint. An embedded engineering relationship that has outlasted every major architectural shift, every growth plateau, every pivot.

The result. 20x growth since 2008. 800,000+ business users. Eloquentix engineers treated as core team — not contractors, not vendors. The most tenured engineer on the product is ours.

We consider our Eloquentix developers as much a part of the Shoeboxed team as their American counterparts. We have relied on them not only for their coding experience, but for their ability to help us solve a range of technology problems that we have experienced while scaling. — Taylor Mingos, CEO, Shoeboxed