Most developers are competent and honest. The ones who aren't tend to signal it early, and the signals are legible even if you can't evaluate code. Here's what I'd walk away from — assembled largely from projects I've been called in to rescue, where the warning signs were visible in week one.
Process red flags
They want to work directly on your live store
For a one-line copy fix, fine. For anything substantial, a developer should work on a development theme or staging environment and then deploy. Editing live means your customers see the mistakes, and there's no clean way back. If someone doesn't volunteer this, ask — and treat a casual "I'll just do it live" as disqualifying.
No written scope
"Just send me a list and I'll get going" feels efficient and ends in an argument. Without a document saying what's included, what isn't, and what it costs, you have no shared definition of "finished." Every disagreement later becomes your word against theirs.
They ask for your account login
Never hand over your own Shopify credentials. A developer needs a staff account with the permissions the job requires — and a collaborator account is the normal route for partners. Asking for your personal login shows either indifference to security or unfamiliarity with how Shopify access works. Neither is reassuring.
The code lives only with them
If you can't get a copy of what you paid for, you're locked in. Ask where the repository is and confirm you'll have access. Vagueness here is sometimes deliberate — dependency is a business model.
Money red flags
The quote is dramatically lower than everyone else's
If three quotes cluster and one is a fifth of them, the cheap one is not a bargain. Usually it means they've misunderstood the job, they'll implement it in the most literal way possible, or the gap will be recovered through change requests. The rework typically costs more than the difference — see what drives rates.
Full payment up front
A deposit is standard and reasonable. The whole fee before any work is visible removes every incentive to finish well. Milestones tied to delivery protect both sides.
Every question becomes billable
Watch how they behave pre-contract. Someone who bills for a fifteen-minute clarifying email during a project you've already paid for is signalling how the relationship will feel throughout.
Communication red flags
They agree with everything
This one masquerades as good service. If you propose something impractical and the answer is always an enthusiastic yes, either they're not thinking about it or they're happy to bill you for your own mistake. You want someone who says "that'll cause a problem with X — can I suggest something else?"
They can't explain anything without jargon
Genuine expertise usually comes with the ability to explain the shape of a problem in plain language. Impenetrable technical language, especially when you've asked for clarification twice, is sometimes a fog to hide uncertainty behind.
Slow, vague replies before you've even hired them
Responsiveness during the sales conversation is the best version of their communication you will ever get. If it takes four days to answer a simple question now, imagine it when your checkout is broken.
Portfolio work they can't explain
Ask what they specifically built on a project they've shown you. People who did the work answer instantly and in detail. Hesitation, or credit for a whole store when they built one section, deserves follow-up questions.
The pattern behind almost all of these: unwillingness to be pinned down. Vague scope, vague pricing, vague answers, vague ownership. Precision is the thing you're actually shopping for.
Things that look like red flags but aren't
Fairness matters here, because some perfectly good developers get rejected for the wrong reasons:
- A high rate. Often the cheaper option overall, if they're fast and it works first time.
- Asking a lot of questions. A sign of someone scoping properly, not someone confused.
- Saying no to part of your request. Usually good judgement, especially with a reason attached.
- A small portfolio. A lot of independent work is confidential, or shipped under an agency’s name. Ask what they can’t show you before assuming there’s nothing there.
- Not being available immediately. Good developers are often booked a few weeks out. Instant availability is neutral information, not a reassurance.
Bottom line
Insist on a staging environment, a written scope, proper access via a staff account, code you own, and milestone payments. Be suspicious of outlier-low quotes and reflexive agreement. And weight pre-contract responsiveness heavily — it's the clearest preview you get of what working together will actually feel like.