How do you actually know if a dedicated developer is good before you hire them?

[Steve jonas]

Honestly, this question comes up more than any other one — not "where do I find developers" but "how do I even know if this person's actually good before I've paid them anything." And most of the advice out there doesn't really answer it.

A slick portfolio doesn't tell you much. Neither does a good call, honestly. Some of the worst hires I've heard about came from people who interviewed beautifully and then just... weren't that good once real work started. So here's what actually seems to matter, based on what keeps coming up when people talk about this stuff.

1. Do they ask questions, or just quote you a number?
If someone gives you a timeline before knowing anything about your codebase, your users, or what you're actually trying to build, that's not confidence, that's guessing. Good developers slow down a bit before they commit to anything.

2. Skip the algorithm-puzzle interview.
Nobody's job is inverting a binary tree. Give them something closer to real work — a messy chunk of code, ask them to point out what's wrong with it, what they'd change. You learn way more from that than from watching someone whiteboard.

3. Notice whether they ever push back.
Not in an annoying way, but like — do they ever say "hmm, that's going to cause a problem later," or do they just agree with whatever you throw at them? I've noticed the ones who never disagree are usually the ones who cause the most trouble down the line.

4. Ask references better questions.
Not "were they good" — ask if they flagged issues early, how they handled scope changes, and whether the client would hire them again. That last one tends to get an honest answer either way.

5. Run a short paid trial if you can swing it.
A week or two tells you more than five sales calls ever will. It's a small cost compared to finding out three months in that it's not working. This is honestly where I've seen the biggest split — the people who actually run a short trial before hiring dedicated developers for hire tend to end up happy, and the ones who skip it usually end up back here asking what went wrong.

Common ways this goes sideways: picking based purely on price, not actually calling references, being vague about IP ownership, and — this one happens more than you'd think — the senior dev who impressed you on the sales call disappears the moment the contract's signed, replaced by someone way more junior. If you're going through an agency, just ask directly if that can happen, and get something in writing about it.

Anyway — has anyone here actually done a paid trial before committing longer term? Did it change anything for you, or was it kind of pointless in hindsight?