Custom software and AI features, built to run in production.
LLM features that hold up with real users, web and mobile apps built from scratch, and modernization of systems that are still running the business. Specified, built, shipped and supported by the engineer who wrote it.
Is this you?
Custom software engagements usually begin with one of these.
- The business runs on a spreadsheet, a shared inbox, or a manual process that one person understands.
- You want an AI feature inside a product or system you already have, and you want it to work with your data, not a demo’s.
- Off-the-shelf software almost fits, and the gap is costing you every week.
- A previous developer or agency left, and nobody can safely change the code they left behind.
- You need a mobile app for customers or field staff, on iPhone and Android.
- Your AI bill is unpredictable and you cannot tell whether the answers are getting better or worse.
What you get.
Working software, measured by delivery, not slideware.
LLM features in production
Assistants over your own documents, structured extraction from forms and email, classification and routing, drafting with review. Built with evaluation sets so you can see quality change, cost controls so the bill is predictable, and a proxy layer so the model can be swapped without rewriting the product.
Web and mobile apps
Native iOS and Android apps and the backends behind them, with sign-in, payments, notifications and the app-store process handled. Keller Tech has two apps of its own live on both stores and has shipped consumer apps for Fortune 500 clients.
Modernization and migrations
Taking over an existing codebase safely, adding tests and CI/CD, and making changes on a live system without breaking it. Includes model migrations: moving a product from one AI provider to another while users keep using it.
How an engagement runs.
Every engagement is led hands-on from the first call through delivery, never handed down to a bench. Data handling is put in writing before any work starts.
Scope
What the software needs to do, who uses it, what it connects to, and what done looks like. You get a written scope and a quote, not a vague estimate.
Build, with demos
Short cycles with working software demoed every week. You see it running on your data early, and change course while changes are cheap.
Ship
Deployment, app-store submission where relevant, monitoring, and a handover with documentation. Data handling is agreed in writing before any production data is touched.
Support
Fixes, improvements and new features on an hourly basis, from the person who built it. You own the code and the accounts throughout.
Why Keller Tech for this.
Fifteen-plus products shipped to production
Sixteen years of production software, including consumer apps for Fortune 500 clients. One of them was ranked #1 in J.D. Power’s first U.S. Credit Card App Satisfaction Study. Five of the products shipped won awards.
AI features we run ourselves
Subtext and Assumptions are AI-native apps designed, built and operated by Keller Tech through its studio, Banked Embers. They are live on the App Store and Google Play, including a model migration carried out on a live product.
The person who scopes it builds it
No account manager between you and the engineer. Questions get answered by the person who knows the code, and the estimate comes from the person who will do the work.
Common questions.
Which AI models do you build with?
Whichever fits the job: Claude, OpenAI, Google, or open-weight models run privately where data must not leave your systems. Products are built behind a proxy layer so the model can be changed later without rewriting the application, which matters because the models change every few months.
How do you keep AI costs predictable?
By measuring. Every feature ships with an evaluation set, so quality is tracked rather than guessed, and with per-request budgets, caching and model selection tuned to the task. Most features do not need the most expensive model, and the ones that do are used deliberately.
Do you take over codebases other people wrote?
Yes. The first step is an assessment: what the code does, what is risky to change, and what tests and deployment it has. Then changes are made in small, tested steps, with a working system at every point.
Do you build mobile apps?
Yes, native iOS and Android, plus the backend, sign-in, payments, notifications and the store submission process. Keller Tech maintains two apps of its own on both stores.
Who owns the code?
You do. Code, accounts, app-store listings and data all belong to you from day one, and are handed over with documentation. There is no lock-in and no proprietary platform.
How is a project priced?
Project-based work is quoted after scoping, with the scope in writing. Ongoing support and smaller changes are hourly. Either way the first conversation is free and there is no charge until scope is agreed.
Work with Keller Tech.
Based on the Mississippi Gulf Coast, working with local businesses and remote teams anywhere. The fastest path is a short email.
Tell us what you are trying to ship.
A couple of sentences about the problem is enough to start. You will get questions from the engineer who would build it.
Biloxi, MS 39530 · Remote