Do I need a business analyst or product manager before hiring a developer?

Not necessarily, but you do need what a good business analyst or product manager produces: a clear, approved description of what to build, gathered from the people who know the work, with disagreements settled before the build. Someone has to do that work. It can be an analyst, a product manager, you, the developer, or a guided process.

The question is less "who" and more "will it get done before the developer starts."

What does a business analyst do?

Interviews the people who do the work, maps the process, finds the rules and exceptions, notices where departments disagree, writes the requirements, and gets them approved. Good analysts are especially valuable when the knowledge is spread across many people.

What does a product manager do?

Decides what the product should do and why, sets priorities, and keeps the team aimed at the outcome. On an internal business app, that role often falls to the sponsor or owner.

When is it worth hiring one?

When the application touches several departments or sites, when the rules are complex or regulated, when nobody inside has the time to gather and reconcile everyone's input, or when you'll keep building on the software for years.

When can I do without one?

When the app is small, one or two people know everything about the process, and you can write down the rules and exceptions yourself. The guide to speccing an app before hiring a developer walks through it.

Can the developer do the analysis?

Some can, and many offer a paid discovery phase. Two things to watch: you're paying developer rates for analysis, and the results may be shaped around how that developer likes to build. Make sure you own the output and can take it to someone else. See what a discovery phase costs.

What should I have, whichever route I choose?

A document with the problem and goal, scope, people and roles, testable requirements, the business rules and exceptions, data and integrations, acceptance criteria, decisions and open questions, ownership after launch, and a sign-off.

Mochlion is one guided route: it works out what to ask the right people, compares their answers, and surfaces the gaps and disagreements for you to decide. See who it's for.