Web & mobile software, built with care in NYC

We build web & mobile software for businesses.

We are a software development consultancy based in New York City. We work with our clients to create high-quality software by using modern Agile engineering practices. Our in-house developers partner with select local designers and product experts to provide full-service application development services for startups and established businesses.

Get your project started

Have an idea or a need, but don’t know how to get it going? Our expert engineers will work with our product and design partners to take your software from zero to launch.

Get your project built

Have a design in hand, but nobody to deliver it? We can act as your development team. Our Agile practices will get you the most valuable, running, tested features delivered reliably.

Get your project working

Have an application that needs a revamp or a rewrite? We are experts at diving into legacy systems and stabilizing them, improving them or replacing them gracefully.


Our clients range from early-stage startups to large, established companies. What they have in common is a need for well-crafted code and a desire for a true development partner. Here are a few of our recent clients.


Empty Team
Owner & Lead Developer
Paul Infield-Harm

Almost twenty years ago, Paul convinced his teammates on a project to give this new thing called “Extreme Programming” a shot. He experienced how effective a development team could be when it focused on repeatably delivering value. Since then, he’s been building on that experience as a developer, technical leader and product manager. He founded Customary to create a place where other builders could experience flow, and where clients could have great work done. When he isn’t working with clients or slinging code, Paul enjoys reading, playing video games and naps.

Empty Team
Owner & COO
Lisa Infield-Harm

Lisa has a deep background in law, finance and real estate, and is in charge of company operations.

Empty Team
Software Developer
Zander Mackie

A small beige cube started Zander’s lifelong love affair with computers. He’s a programmer, software entropy fighter, and parent to three foundling pets. He loves good tests, sparklingly clean code, and programming languages like Ruby, Javascript, and Elixir. He’s fanatical about writing manageable and flexible code. For someone who wanted to be Merlin when he grew up, Zander feels like he’s pretty close to the mark.

Contact us

We’d love to hear from you! Drop us a line or give us a call.

Email: info@customary.nyc
Phone: 917-509-3356