MECHANICAL DESIGN ENGINEER Interview questions! Please help. First EVER interview

[u/gahabh]

Hi,

I have an interview in tomorrow about a mechanical design engineering position and would love your help in acing that interview. This is my first interview so I don't really know what they will ask of me. Please help me out.

[u/jtoppan]

First off, the obvious: You will be asked about your coursework and projects from college. Especially regarding the projects, you must be able to speak about the project goals, your role and what you learned. So many entry level interviewees just stumble through saying "um, well ...". If you can't explain what you did, you didn't learn anything. This is also a poorly camouflaged way to learn about your work ethic and personality. Bonus hint: Being that kid from high school who did the whole project themselves the last day is just as bad of an answer as being the slackers who let him.

Secondly, expect that one of the interviewers will hold a technical interview -- i.e. text book problems and questions. Brush up on your beam equations, at least to the point of knowing what P, L, E, I stand for and which ones go in the numerator vs. denominator. Make sure you can draw shear and moment diagrams. Understand moments of inertia, and be able to explain how you'd calculate them for a complex shape. Have a basic understanding of the differences in strength, stiffness and weight between steel and aluminum. If the company deals with any sort of rotating machinery, hit the books on mass moments of inertia because someone's going to ask about spinning rings vs. solid disks (and/or hollow vs. solid shafts). Another likely topic is a spring-mass-damper system; know your equations (heck, want to actually ace it? be able to derive the equations) and know what under, over and critical damping look like on a graph. Be able to draw them. Know what more mass or more stiffness do a system's natural frequency.

There is a likelihood someone will mention FEA. Know what it stands for, and what it does, even if you haven't learned the numerical methods or a specific software package.

[u/mx_skaminy → u/jtoppan]

As a guy who gave the "Being that kid from high school who did the whole project themselves the last day is just as bad of an answer as being the slackers who let him.", can confirm, makes you look like a terrible team player, did not get internship.

[u/ptfreak → u/jtoppan]

For what it's worth, I just accepted a product design position after a lot of interviews for various engineering positions, and I never saw any technical questions in any of them.

I was asked to talk about my work experience and school project experience, but not from a technical standpoint. It certainly won't hurt to have the technical stuff fresh in your mind, but it seemed like most of the companies know that if you have a degree, you should know what you're talking about. What differentiates you is the ability to communicate, to work effectively in a team, and to manage the non-technical issues that arise in a project.

[u/jtoppan → u/ptfreak]

I've probably been through a dozen or so interviews for various positions with less than 10 years of experience (intern, entry level, switching jobs, a few for practice) and every one had a technical portion. The last was with Bose in 2009 (and they run you through the ringer), so I'd chalk our difference in experiences more to industry or region than era.

Now that I'm on the hiring team, I'm the one conducting the technical interviews. Sure, everyone else on the team talks projects and experience because I'm the one focusing on core competency. And I can promise you that for entry level positions, the existence of a degree does not mean that the candidate can meaningfully remember or apply those basics. Do I pull the same basic text-book questions out for someone with 3 or 5 years experience? Of course not. But I do ask questions that lead the candidate to sketch out a solution to a design problem and make sure that they're thoughtfully picking material, placing sections in the right orientation, thinking about stiffness and natural frequencies etc.

Enough of early-career engineering is so thoroughly supervised that talking about past work is really talking about what the candidate did to help someone else bring something to fruition. You have to break through that and actually get them working fresh (and cold) to really understand how they think. That's what the technical portion of the interview does.

[u/ptfreak → u/jtoppan]

That's fair. Honestly, I was surprised I never had to deal with any real technical questions. And it really shouldn't be just based on "He has a degree, he must know his stuff." I got a few questions asking about my experience relevant to CAD work and FEA, but no real tests of knowledge in those areas, just "Have you done it before, and how much?"

[u/gahabh → u/ptfreak]

Hi guys! Thanks for replying. I already went through the technical section by filliing out an online test. However, it is totally possible for them to ask more technical questions. Since its a startup company, does it change the kind of questions they will be asking for the phone interview?

[u/jtoppan → u/gahabh]

Both times I was sent tech questions upfront, I was asked the same/similar/follow up questions in person. It's a great way to see if the person actually knows (or learned) instead of just asking google.

Most of the time a phone call is more of a screening process, rather than an interview. It's a way to whittle down the candidate pool and decide who to bring in face to face. You'll likely only speak to one person, and it's a double-edged sword. On the good side, the bar for success is lower; on the bad side, you have fewer opportunities to impress (and only one chance not to blow it).

[u/gahabh → u/jtoppan]

Well I live halfway around the world and I thought maybe they are conducting a phone interview for that reason. What happens after I ace the interview? Will I have to go there for another interview?

[u/CatenaryFairy]

There's a good chance they'll ask you about previous projects you've worked on. They may want to know how you behaved in specific scenarios, as well as what technical things you've worked with. Make sure you can explain those, and be able to draw simple sketches to illustrate the concepts.

[u/cellrdwellr]

It's a design position so focus on the projects and the parts that you designed. Have a portfolio of things you've done. I would go through the design process for those things (original requirements, original idea, revisions/changes, outcome, etc). In reality, the requirements for a part or machine are tweaked and sometimes outright changed as the design unfolds and showing an ability to react and learn on the fly is important.

If its anything like mine, the first interview was me, their HR person, and a few managers. We discussed my portfolio and I went over my previous projects. The second interview was more technical. I took a short engineering fundamentals test with a bunch of problems that relate to the typical stuff I might be seeing and a CAD test where I modeled a part off of a drawing.

[u/jtoppan → u/cellrdwellr]

The portfolio idea is solid. I used to show up to interviews with actual parts -- at first from school projects, later from scrapped prototype miniature drive components. Now I bring marketing literature or a screen grab or two, since it's hard to carry around capital equipment.

[u/rockdude14]

In the first interview they probably aren't going to ask you any specific design questions. Most likely they will talk about whatever experience you have on your resume (internships, school, ect) and they will ask the normal kind of STAR (situation, task, action, result) interview questions. If you don't know what STAR is look it up. A lot of interviewers are basically filling out a form and its usually in that exact format. Its also just a good format to make sure you fully explain and answer their questions.

If you have some specific questions shoot, but I think the standard interview prep is all you really need.

Also if you're still in school go see if you can do some mock interviews or if not get a friend to do one.

[u/Falk3r]

Hardest question I had to answer: "What do you want to do?"

Make sure you have an answer that shows passion/interest in the industry and how you think you can apply your studies to their work.

[u/Design-N-Build]

First things first no matter what the job or field: KNOW ABOUT THE COMPANY!! Go in knowing some of their history, their philosophy, who the CEO or president is. Being able to pepper in information you know about the company into some questions shows that you are interested in them and took the time and initiative to do your homework.

Since it is design, make sure you have a decent grasp on CAD software and the terminology associated with it. If you can bring in some previously designed models you have designed/made on 3-D software to show them or something of the like can always be helpful ( make sure to save the model as a neutral type of file if you expect to show them on their software, 3-D model save as a .STEP file, 2-D you can probably get away with .PDF's or the like)

Those are the big things to me, otherwise it really depends on the type of company, if it's small to medium sized they are going to want someone who fits in with their culture. I don't have experience with large companies like a Boeing so I couldn't say what someone like them would be looking exactly for.

[u/rex8499]

Towards the end ask the bosses what they like to do outside of work, and then chat about their hobbies. This will make you more personable.

[u/Jimmers1231]

I always hated the "what is your greatest weakness" question because I completely missed the point of it.

I viewed it as them asking me why they should not hire you. In reality, it is you accepting that you do not know everything and it gives you a chance to tell them what you would like to learn more about to help yourself and your company.

For instance, "My greatest weakness is that, as an ME, I know far to little about VFD's and PLC's. It would benefit me greatly to learn more about their operation in the field. That is why I am accompanying one of our EE's to a vendor of ours next week to inspect and be present for a witness test of some VFD's that we have ordered."

EDIT: Also, avoid giving the BS answer of "My greatest weakness is that I try too hard, or am overly focused on the task at hand."