Ken Vermeille
CEO & Founder
15+ years shipping production subscription apps. React Native, iOS, Android, RevenueCat, Superwall. Embedded with PE portfolio companies and high-growth startups through acquisition.
Read full bio→About Vermillion
The alternative to hiring an in-house team.
Senior mobile engineers embedded inside your product within five business days. No recruiting cycle. No ramp time. One function, accountable for what ships.
Why we exist
Why Vermillion exists.
We work with subscription mobile teams where growth has outpaced what engineering can ship at current headcount.
Most teams we embed with already have distribution and a revenue story. The constraint shows up in shipping cadence, incident load, and experiment backlog, not in founder-led sales capacity alone.
Marketing and growth move fast. Growth wants experiments on short cycles. Then a feature request hits engineering and takes six weeks. The pricing test that should have launched on Tuesday gets queued behind a release. The webhook that should have processed last night's renewals quietly drops half of them. And the founders who should be selling end up managing developers.
The hiring fix takes two to three months at minimum, longer when you have a high bar. A senior React Native engineer in the US means six-figure base, equity and recruiter load, plus benefits, plus the time it takes to find them. Once hired, they're one person. They burn out. They take vacation. They leave for a unicorn.
We are the alternative. The fractional mobile engineering function. Senior team, AI-first workflow, fifteen years of subscription mobile authority, starting in five days. We don't take projects. We don't bid hourly. We become the engineering team you'd hire, and we stay until your company is acquired or you've built your own team.
PicklePlay shipped with us through acquisition by Universal Tennis. Artfare we built from zero and stayed embedded to grow. Washlava we shipped through eight million raised across rounds and a multi-year IoT deployment. The pattern is the same: we don't deliver code and leave. We become the engineering function and stay.
Our proof
Our proof.
Partnerships measured in years, exits in headline news, users in millions, capital in funding rounds we helped engineer through.
We've spent fifteen years building the engineering function for consumer mobile companies that ship subscriptions. The numbers below are the durable kind.
15+
Years building products that scale and exit
1M+
Users supported across client products
27M
Raised by founders we've engineered with
4
Founder exits supported through acquisition
We work in React Native, Expo, and TypeScript. We integrate RevenueCat, Superwall, and Adapty deeply enough to be known in those ecosystems. We treat technical due diligence as a feature, not a fire drill. We measure success by the companies that acquire our clients, not by tickets we close.
Leadership
Leadership.
Senior operators who've shipped through funding rounds, acquisitions, and the long quiet middle in between.
Irem Gultekin
Director of Product Management
Product strategy and execution with experience at Amazon, Apple, and high-growth startups. Leads discovery and roadmapping with a focus on clarity, velocity, and measurable outcomes.
Read full bio→
Mark Montgomery
Creative Director
Brand and product design systems for Spotify, Apple, and global enterprise clients. Leads design with a focus on systems thinking, conversion clarity, and craft.
Read full bio→Our values
Our values.
These aren't posters in a kitchen. They're how we choose what to ship and what to push back on.
Excellence without ego.
Quality that stands up to scrutiny. Code that survives technical due diligence. Architecture that compounds.
Speed from seniority, not corner-cutting.
We move fast because we are senior, not because we cut corners. AI tooling amplifies senior platform expertise. It does not substitute for production scars.
Integrity through transparent truth-telling.
We tell clients what they need to hear, including when they should not hire us, when their idea is wrong, and when their existing team is the problem.
Commitment that extends beyond launch.
Our engagements end in acquisition, IPO, or graceful in-house transition, not in deliverable handoff and walking away.
Delight in the details.
We care about how things feel, not just how they work. Cold start time matters. The animation curve matters. The empty state matters.
Beauty in codebases and experiences.
Code is read more than it is written. A beautiful codebase is a maintainable codebase. A beautiful interface is a trusted interface.
Our commitment
Our commitment.
We are embedded for the long haul. We don't disappear after launch. We don't bill for handoff. We stay in your Slack, in your codebase, and in your sprint planning until you've built your own team or the company is acquired. That's the only kind of partnership we do.
When you're ready to graduate and bring engineering fully in-house, we help. We write the senior engineer JD, source candidates from our network, run technical interviews, and onboard the new hire to the codebase we've been running. We make exit so clean that the relationship continues.
№ 012 · Ready to embed?We become the engineering function.
We become the engineering function.
We stay until you have built your own.
15 minutes. No pitch. We learn your stack and tell you honestly if we are the right fit, including when we are not.
Talk to the team15 minutes · No obligation