PORTFOLIO ONESPARK BLOG ABOUT FAQ BOOK A SCOPE CALL

For teams and businesses who know what needs to be built

You know the build. We own the delivery.

New builds, rescue builds, new features, internal tools, compliance-driven software. You tell us what needs to ship and when. We come in, own the sprint, and guarantee delivery. Fixed price. Fixed deadline. 5% back for every business day we're late.

Book a Scope Call

New Builds · Rescue Builds · New Features · Internal Tools · Compliance Software · 5% Back Per Day Late

You already know what needs to be built. The problem is getting it built.

You're not here to figure out what your product should be. You know. You have a spec, a feature request, a failed build that needs rescuing, an internal tool your team can't wait three months for, or a milestone deadline that can't be moved. What you need is someone who can actually execute on it.

The Agency That Overpromised

They said yes to everything in the sales call. Then the kickoff happened. The requirements drifted. The timeline drifted. They handed you something that wasn't what you asked for — and asked you to pay for it anyway.

The Team Drowning in Core Product

Your engineers are heads-down on the things that can't slip. This new build, this rescue, this feature can't wait three months for them to surface. Hiring takes six months. Contracting takes weeks of vetting and onboarding.

The Freelancer Who Disappeared

They were great. Then they vanished. Now you have half a build, no documentation, and a deadline that's closer than ever.

The Vibe-Coded Prototype That Hit a Wall

Lovable, Bolt, Cursor — it shipped fast, looked good, then broke at scale or hit a compliance wall you didn't know existed. Now you need someone to do it properly.

You don't need another estimate. You need delivery.

A full build, owned end to end, guaranteed on a date.

We don't operate like a typical agency. There's no project manager between you and the build. No four-week discovery phase. No quote that turns into three. You bring us a defined need — we come in, scope it precisely, and ship it on a date you can plan around.

What "Custom Software" actually covers:

  • New builds — a defined product or system, scoped and shipped end-to-end
  • Rescue builds — your last team didn't deliver. We come in, assess what's there, and ship what should have shipped six months ago
  • New features — a specific feature or module added to your existing product
  • Internal tools — operations dashboards, admin panels, data pipelines, anything your team needs to run
  • Compliance-driven software — HIPAA, SOC 2, GDPR, PCI DSS, WCAG, ADA. Built into the architecture, not bolted on later

Across all of these, the same operating principles apply: a working prototype before you sign, a fixed price and delivery date in your contract, live staging from day two, daily progress, full code ownership, and the 5% per business day late guarantee.

"I would recommend OneChair because it's more cost-efficient and you can get to product-market fit in 1/10th of the time. The speed and ability to push features — that's the biggest benefit."

Arjun Banerjee, Founder, WingmanAI · Frontend & AI rebuilt in 33 hours · Full dev team replaced

What you get with a custom build

  • Working prototype before you commit a dollar — see your build in OneSpark before signing
  • Senior engineering on every line — every output reviewed before it reaches your repo
  • Live staging from day 2 — share with your team, stakeholders, or investors at any moment
  • Daily build updates — see what shipped every day, not in weekly status meetings
  • Fixed price — locked into your signed contract, no scope-creep invoices
  • Fixed delivery date — locked in too, with the 5% per day late guarantee behind it
  • Full code ownership — every line, full documentation, complete access from day one
  • 100% requirements matched — what you scoped is what we ship
  • Compliance built-in — HIPAA, SOC 2, GDPR, OWASP, WCAG, PCI DSS as your project requires

The Guarantee

Your deadline — guaranteed.

Every Custom Software project has one delivery date in writing. If we miss it, you get 5% of the project price back for every business day late — up to the full project value.

In the rare case we're a full month late, the project is free.

This isn't marketing language. It's in your signed contract. We built OneSpark specifically to hit deadlines that traditional agencies miss — and we put our money behind it so you can plan around it.

From scope to launch

01

Book a Scope Call

Fill out a short form. We review everything before the call so we come prepared. No fluff, no pitch.

02

30-Minute Scope Call

You tell us what needs to be built and when it ships. We work through features, users, integrations, compliance. You leave knowing your timeline, the prototype process, and what the guarantee looks like.

03

Working Prototype + Fixed Proposal

Before you commit a dollar, we feed your scope into OneSpark and produce an early working version of your build — plus a fixed-price proposal. See it. Click it. Share the link. Then decide.

04

Requirements Workshop

Once you're in, we run a 2–4 hour deep dive to lock every requirement. Edge cases, integrations, user flows. The prototype gets refined. The scope gets locked. The clock starts.

05

Full Build — Guaranteed

We execute the project. See progress every day on a live staging URL from day two. Fixed price. Fixed delivery date. 5% back per business day if we're late.

Book a Scope Call

Want to see what we've shipped?

Our portfolio includes B2B AI platforms, aviation operations systems, healthcare compliance builds, internal asset tracking, and more — all delivered on fixed deadlines, all owned by the clients we built them for.

See Full Portfolio →

Every build is different. Every price is locked.

Every Custom Software project is scoped and priced based on your specific requirements, timeline, and complexity. Tighter deadlines and broader scope require dedicated resources.

What's the same on every project:

  • Fixed price in your signed contract — no scope-creep invoices
  • Fixed delivery date in your signed contract — backed by the 5% per day late guarantee
  • Working prototype + proposal within 48 hours of your scope call — before you commit a dollar
  • Full code ownership from delivery onward

You see the price and a working version of your build before you sign anything.

Book a Scope Call →

Who we build custom software for

  • Product teams with a feature on the roadmap that can't wait for the in-house team to free up
  • Founders and operators with a failed build that needs to be rescued and shipped properly
  • Businesses launching a new internal tool engineering doesn't have bandwidth for
  • Companies facing a compliance deadline for HIPAA, SOC 2, GDPR, or similar
  • Anyone with a defined scope, a deadline, and a need to ship

Who it isn't for

  • You're launching something new to test an idea — that's an MVP Build
  • You haven't validated what you're building — start with a Prototype Sprint
  • You already shipped and need ongoing development — that's the Technical Partnership
  • You want hourly billing or à la carte work
  • You don't know what needs to be built yet

Common Questions

An MVP Build is for when you're validating a new idea — when you need to test, learn, and figure out what to build. Custom Software is for when you already know what needs to be built. You have a spec, a failed build that needs rescuing, a feature request, a compliance deadline. The requirement is execution, not discovery.

Yes. We assess what's there, determine what's salvageable, scope what needs to be rebuilt or completed, and deliver the finished product on a fixed deadline with the 5% per day late guarantee behind it. We've done this more than once.

It depends entirely on scope. WingmanAI's frontend and AI were rebuilt in 33 hours. Cody Yellowstone shipped in 12. Larger builds — HIPAA platforms, multi-module enterprise systems — take longer, and we scope them honestly. What we commit to is a fixed delivery date in writing, backed by the guarantee.

Every project is scoped individually. You see the fixed price — and a working prototype of your build — before you sign anything. There are no scope-creep invoices after the fact.

Yes. Every line, full documentation, complete repo access from day one. No lock-in, no licensing fees, no ongoing dependency on us to run what we built.

That's a Custom Software project. Scope it, price it, deliver it on a fixed date. It doesn't need to be an entire product rebuild to qualify.

Compliance is built into the architecture from the start, not bolted on at the end. WellChild is a live example — a HIPAA-compliant pediatric healthcare platform delivered with full compliance documentation. We build to HIPAA, SOC 2, GDPR, OWASP, WCAG, and PCI DSS as your project requires.

Yes. Rescue builds and new-feature projects routinely involve inheriting an existing codebase. We assess what's there before scoping, so the fixed price reflects the actual state of what we're working with.

Scope is locked in the requirements workshop, and the fixed price and delivery date are based on that locked scope. Changes after sign-off are scoped separately. This is how we protect both the deadline and the price.

Every output from OneSpark is reviewed by senior engineers before it reaches your repo. We use AI to move fast — not to cut the review step that makes quality possible. The code you receive is production-grade, documented, and built to be maintained.

That's the Technical Partnership. Once your Custom Software project ships, if you want a continuous development team rather than project-by-project delivery, the Technical Partnership is how we structure that.

Ready to ship?

Fill out the form. We review every submission before the call and pre-fill your project outline so you don't repeat yourself. Come ready to move.

See our Privacy Policy and Terms of Service.