I think its going to be difficult to impossible to determine that in advance. Even visiting and touring the workplace, you'll likely see people on their best behavior.

Your best chance to get a feeling for this might be to ask about their HR policies. Questions like:

1. How big is your organization? (If you're in the US, companies under a certain size are exempt from certain anti-discrimination laws.)
2. Do you have a dedicated HR department? (Or would any problems be dealt with by management?)
3. Before hiring, can I see a copy of your employee handbook? (Do they even have one? Do they have specific policies written policies about harassment? Do they define a grievance process?)

If you have a non-technical interview with someone in personnel, these would probably be more appropriate to ask than during your technical interview.

Unfortunately, even finding a company with good policies doesn't guarantee anything about your manager or your coworkers.

Check the "Glass Door" review site, but since every review is written by a disgruntled employee, take it with a grain of salt.

If you can, see if you can find an opportunity to chat casually with other female engineers (if they have any!). Ask open-ended questions like, "how is it working here?" or "is it hard working here as a woman?"

I think its going to be difficult to impossible to determine that in advance. Even visiting and touring the workplace, you'll likely see people on their best behavior.

Your best chance to get a feeling for this might be to ask about their HR policies. Questions like:

1. How big is your organization? (If you're in the US, companies under a certain size are exempt from certain anti-discrimination laws.)
2. Do you have a dedicated HR department? (Or would any problems be dealt with by management?)
3. Before hiring, can I see a copy of your employee handbook? (Do they even have one? Do they have specific written policies about harassment? Do they define a grievance process?)

If you have a non-technical interview with someone in personnel, these should probably be asked there instead of during your technical interview.

Unfortunately, even finding a company with good policies doesn't guarantee anything about your manager or your coworkers.

Check the "Glass Door" review site, but since every review is written by a disgruntled employee, take it with a grain of salt.

If you can, see if you can find an opportunity to chat casually with other female engineers (if they have any!). Ask open-ended questions like, "how is it working here?" or "is it hard working here as a woman?" They may be able to read between the lines of your question and give an honest response.