Capability · Mobile app development

Mobile apps built to scale
without the rewrite.

We build, protect, and scale mobile products that pass due diligence and survive growth. Senior judgment on architecture and releases, not order-taking. So you are not rebuilding six months from now.

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Fast shipping without technical judgment is expensive.

Whether your code came from contractors, a departed founding engineer, or fast iteration, the failure mode is the same: velocity without someone asking whether you are building the right thing for the next stage.

The mistakes that kill companies are not minor bugs. They are decisions: the wrong architecture, the wrong data model, the shortcut that saves a week now and costs a quarter later.

We build with that lens. Not only shipping features, but making sure what ships can survive diligence, hiring, and scale.

Build. Protect. Scale.

Three ways to engage depending on where you are. Each is anchored in technical judgment.

Build with judgment

Most teams build what you ask. We build what you need and push back on the rest. For teams that want owners, not ticket-takers.

Protect what you have shipped

Your codebase carries risk you cannot see from the roadmap. We audit the decisions that hurt you later and give you a clear plan.

Scale with confidence

You have momentum. You need a partner who can grow with the product and tell you what not to build. For teams that need leadership without a full-time mobile executive.

How we get apps to diligence-ready shape.

Technical audit and architecture

We map the system, find what breaks at scale, and sequence the fix. You leave with a roadmap investors can read.

Typical window · two weeks

Core infrastructure rebuild

React Native and TypeScript for most products. Monitoring, tracing, and release hygiene built in from the start.

Typical window · eight to twelve weeks

Security and compliance posture

Authentication, data handling, and vulnerability work aligned with what auditors and buyers actually check.

Typical window · four weeks

Performance and reliability

Load time, stability, and release risk addressed as engineering work, not slogans.

Typical window · four to six weeks

Investor-ready documentation

Architecture notes, test posture, and the narrative reviewers expect during diligence.

Typical window · two weeks

Traditional agency compared to Vermillion.

Traditional agencyVermillion
Junior-heavy benchesSenior engineers
Retainers without clear outcomesScoped work and explicit handoff paths
Hands off after launchTrain your team or plan graduation
Build exactly what you requestTell you what you actually need
Hourly billing by defaultClear phases and timelines, scoped per proposal

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React Native for subscription mobile.

One codebase for iOS and Android, TypeScript end to end, Expo where it shortens the path to reliable releases. For stack detail and conventions, see React Native development.

  • Single codebase for both stores
  • Type safety and testable modules
  • Native modules only where the product truly needs them

Native iOS and Android when it is warranted.

Sometimes the product needs maximum platform integration or real-time media. We ship Swift and Kotlin with the same diligence bar as our React Native work.

iOS

Swift, platform conventions, and release discipline that fits App Review.

Android

Kotlin, real-device coverage, and behavior across OEM variance.

Platform strategy.

The question is not a slogan. It is what gets you to the next stage with a codebase you can defend.

React Native first when

  • You need both platforms from one team
  • The product is content, subscription, or business-logic heavy
  • Iteration speed matters more than bespoke per-platform UI

Native first when

  • Deep AV, AR, or hardware integration dominates the roadmap
  • You are optimizing around platform-specific differentiation

Hybrid when

  • Most of the surface is shared, a thin slice needs native modules

Backends that match the app.

APIs, auth, jobs, and data stores sized for how subscription apps actually fail: webhooks, receipts, entitlements, and operational visibility.

We work in Python, NestJS, and Go depending on your team and constraints. Infrastructure on AWS or GCP, containers, CI/CD, and observability wired in.

Expo and over-the-air updates.

When the client layer allows it, Expo Updates shortens the loop from fix to users. Native changes still ship through store review. We are explicit about which class of change belongs where.

PicklePlay is our reference: critical client issues addressed quickly, stores and tooling kept stable through a high-growth arc and acquisition.

PicklePlay: from broken release rhythm to acquisition.

Rebuilt the mobile surface and backend contracts, cleaned state and observability, and made the story legible to buyers. User base scaled materially; outcome was acquisition by Universal Tennis.

Vermillion rebuilt our app in 12 weeks. We went from losing users daily to 200K active users. UTR acquired us shortly after.
Blake Renaud, Founder, PicklePlay

Typical phases.

Weeks 1 to 2

Audit

Codebase read, risk list, and rebuild or migration sequence. You get a written plan.

Weeks 3 to 14

Core rebuild

Demos on a cadence we agree with your team. Stability and scope move together so leadership can see progress.

Weeks 15 to 20

Hardening and handoff

Documentation, tests, runbooks, and training so your team or the next hire can own it.

Scope and commercials.

MVPs, rebuilds, and ongoing support are quoted after we understand the codebase and your runway. Pricing per scope. Buyers ask on a call.

  • MVP-scale builds are usually eight to twelve weeks of focused execution
  • Full rebuilds often land in the sixteen to twenty week range
  • Maintenance is monthly scope, not a public rate card

How we run the build.

  1. Discovery. Interviews, repo read, risks, and a signed plan.
  2. Design and architecture. Flows, contracts, and integration points agreed before heavy build.
  3. Sprint delivery. Demos on a fixed cadence.
  4. QA and release. Devices, store submission, rollback strategy.
  5. Handoff. Access, documentation, and training.

Mistakes we see in diligence.

  • Shipping breadth before the core journey is solid
  • Treating performance and stability as a later phase
  • No automated safety net around releases
  • Security and data handling treated as a checklist bolt-on
  • No written architecture for reviewers

Sectors we ship in most often.

Healthcare and telehealth

HIPAA-aligned flows, device reality, secure transport.

Fintech and payments

PCI-minded integrations, KYC flows, reconciliation.

Social and community

Realtime surfaces, moderation hooks, push infrastructure.

Marketplaces

Payments, discovery, fulfillment loops.

Sound familiar?

  • You have spent heavily on build and still cannot explain what you own.
  • Short-term fixes from months ago are still load-bearing.
  • No one internal can give you an honest architecture review.
  • You are approaching a round or an exit and the stack is a black box.

If any of these is true, start with a short call. 15 minutes. No pitch.

Frequently asked questions.

How is this different from a dev shop?

Dev shops execute tickets. We challenge the plan, sequence risk, and ship with diligence in mind.

Do you take greenfield and rescue work?

Yes. Scope starts with audit and alignment, then build.

How long does an MVP take?

Most MVPs fall in an eight to twelve week band. Complexity and decision speed move the needle.

Can you help with due diligence?

Yes. We have supported teams through technical diligence and financing with founders we engineered alongside.

Next step.

15 minutes. We surface the biggest technical risks and a realistic sequence. No pricing deck on this page.

Book a 15-min Strategy Call