How I Became a Staff Design Engineer at Tesla Materials Engineering

In this first article about my career at Tesla, I want to start with why the role at Tesla Materials Engineering was attractive to me and the hoops I needed to jump through to get onboard.

My primary goal of writing about my time at Tesla is for you to know me better, what my skills are and where I thrive. It's also my hope that engineers and new graduates who're considering joining Tesla get a taste of becoming and being an engineer at Tesla, which for a long time, has been one of the top destinations for engineers along with SpaceX .

On September 30th, 2021, I applied for a position at Tesla Materials Engineering, the team best known in the industry for developing the Giga Casting process that molds the front and rear ends of the Tesla Model Y, consolidating dozens of parts into two and deleting hundreds of resistance spot welds and fasteners. The same team also engineered the stainless steel exoskeleton of the Cybertruck, including the alloy and the surface finishing process resulting in probably the first production vehicle in history that's not painted.

Here's the job description and I highlighted the parts that attracted me the most. The job reads like perfectly tailored for me since I am not only attracted to technical challenges out of innate curiosity, experienced with designing custom material testing and design validation fixtures and crafting test methods during the development of products that did not exist with no industry best practice to follow and developed manufacturing processes with suppliers and contract manufacturers that either involved new materials or conventional materials processed or used under unprecedented conditions, but also that I had spent more than ten thousand hours in the lab building prototypes, preparing specimens, running tests and conducting failure analysis since graduate school.

The Role:

The purpose of the Materials Applications Team is to accelerate the adoption of new materials and processes at Tesla. Our goal is to work on problems that make step changes in the optimal design space.

As a Design Engineer on the team, you will bridge the gap between materials science and part design. That can mean many different things depending on the material or process. On any given day you might design prototype tooling to make trial parts, work with vendors to perfect a process, perform large design space studies to see how a new material impacts mass and cost, or work in the lab to characterize a part or system.

Responsibilities:

1. Meet with materials engineers to understand strengths and weaknesses of proposed materials or processes and how those affect part design
2. Meet with part owners in design teams to understand design requirements for their parts
3. Create models to demonstrate the possible gains offered by a new material or process
4. Create 3D and 2D CAD for prototype parts and/or tooling
5. Source prototype parts and tooling
6. Design test plans for prototypes and assist in test execution and data collection
7. Report out results to executives with recommendations for next steps
8. Work with the design, test, sourcing, program management, and finance teams to transition new materials and processes to production

The Phone Interviews

On October 13th, I spoke with Matthew Redhead who then arranged an online test required for all Mechanical Engineering candidates. Since I had been out of college for nearly 20 years by then, I gave myself a few days to prepare for this open-book and open-internet test. I did OK and was informed on the 18th that the hiring manager would like to talk.

The first time I got on a Teams call with David Nelson , I could tell he is the manager I want to work with. We spoke about everything from stress-strain curves to creep and fatigue of metals to glass transition temperature of polymers for a little over an hour. By the end of the hour, he decided that there needs to be another interview with him in a week.

In the end, Dave and I spoke over three separate sessions for a total of about 4 hours. He asked the most interesting physics, materials, mechanics of materials and mechanical design problems and they were all designed to be solved using first-principles approach. For example, explain what happens when you bend a paper clip back and forth and how many horsepower can an average person walk, run or cycle at? He encouraged me to ask for more information that he might have forgotten to provide and he evaluated my answers by orders of magnitude and the approaches and iterations I took to arrive at my answers.

Reflecting on the phone interviews, I think Dave was not only probing the breadth of my experiences, the depth of my knowledge in various fields and whether I built and tested something by myself and what are areas I need help with, but he was also methodical in examining how patient and persistent I can be in the face of challenges that may have multiple solutions or it may not be obvious if a solution even existed, would I quickly get on an easy path but also quickly throw my hands in the air and say "I don't know, tell me the answer" or would I deliberate, ask for more information and try to approach the problem from different angles.

The Onsite Interview

On December 3rd, I went to the Deer Creek office to meet the team. At the time, a large number of Tesla engineers were already working onsite, unlike software and hardware engineers at other companies who were still working from home 100% of the time. I gave a 30-minute presentation which I revised twice to cut the words on the slides by 50% based on Dave's feedback and had presented to my wife and then 5th- grade and 7th-grade kids twice as well. The presentation went well.

I will not write about the Q&A's with the interview panel, but for myself, I went with two questions to the onsite interview.

First, I wanted to know what exactly the team meant by "accelerating the adoption of new materials and processes" because Tesla is known in the industry for being a disruptive leader for famously proclaiming to all OEMs "All our patents are belong to you" for the confidence that no one can innovate as fast as Tesla can.

The interview panel included polymer material engineers, design engineers and team leaders. The gap identified in the job description was obvious. Materials engineers focus on material characterization for establishing structure-process-property relationships and failure analysis. Mechanical engineers design their parts using materials that are known to the industry for decades. When a materials engineer develop a new material or acquire a new material from a supplier, it most likely requires some tweaks to the part design and manufacturing process and additional testing to ensure nothing unexpected happens when the new material is integrated in the system. Since design engineers typically don't have the time or required materials background to do all of these, in the end the part is still designed and produced using conventional material and process following industry best practices and the more promising new materials and processes are shelved for the next generation of design which can be 1 or 2 years later. Having someone who can design a part based on thorough understanding of the strengths and weaknesses of a new material and taking the part through validation and to production will definitely accelerate its adoption.

My 2nd question or goal was to be aligned with the team on what values I bring to the table and what are areas for growth. Dave's recommended method for extracting my contribution to any project or any team, or what values I bring is a tool I continue to use today, which is asking yourself "what wouldn't happen if I weren't there?" It was clear by the end of the interview that my experience working with new materials and testing materials and parts and developing manufacturing processes for unconventional applications positioned myself well for the team's need. As to areas for growth, I hadn't used CAD tools on a daily basis, but the team wasn't worried that it's something that couldn't be overcome.

The "Evidence of Excellence" Write-Up

On December 10th, Matt got back to me with a decision to move forward, with two more milestones to pass. Tesla is known as the largest start-up in the world and one tradition they kept for many years was that all engineering hires must be signed off by Elon Musk himself. This meant that the hiring manager, director and vice president of the department must present an "Evidence of Excellence" write-up of any engineer they hire and if Elon Musk isn't convinced, there will be no offer; but if you are hired, you can tell the world that Elon Musk agreed that you are excellent at what you do.

This is what I wrote in December, 2021.

While at General Motors, Ron developed an ex-situ accelerated creep and fatigue testing system that cut the durability testing of proton exchange fuel cell membranes from 3+ months to less than 1 week. The unique testing system allowed General Motors and suppliers from around the world to develop robust, efficient and low-cost membranes far exceeding US DOE targets. (2008 ~ 2011)

While at General Motors, leveraging his good understanding and creative use of Digital Image Correlation, Ron measured the whole cell to cell slippage history with 10-micrometer resolution during crash tests of a 400-cell fuel cell stack up to 55MPH. The measurement provided critical data to the structural redesign of the stack enclosure for stack crash safety. (2012)

While at Carbon, Ron solved a distortion problem long thought to be intrinsic to dual-cured resins, 3D printed with UV light followed by thermal bake in baking pans. He first proved that the “potato-chipping” of thin parts during baking was due to asymmetrical evaporation of solvent and outgassing while the materials have very low stiffness before cured at the baking temperature. He then experimented with perforated baking pans and BBQ grills and meshes. Once proven successful, his solution was immediately adopted by all Carbon customers. From thereon, all Carbon parts (in multiple millions by now) are baked on BBQ meshes or in ventilated “cradles” for all-over heating and outgassing. (2017)

While at Carbon, Ron developed a damping elastomer that single handedly saved and then accelerated a strategic program in which Carbon and Riddell produced 3D printed cushion pads for the safest football helmet as rated by the NFL. The program brought in millions of dollars for engineering development and 10s of millions of dollars of annual revenue since 2019. (2018)

The Executive Interview

The other milestone is a final Teams call with Dave's manager, Senior Director of Materials Engineering, Paul Edwards . On December 22nd, I called into Teams from my hotel room during my family retreat at Diamond Peak and like most Tesla engineers, Paul wasn't on vacation yet.

If you've watched YouTube videos of Lars Moravy or Drew Baglino talk about the materials and manufacturing of the Cybertruck, Model 3 or batteries and motors, you know that Tesla managers, directors and vice presidents, don't just manage a team of engineers and managers, they are the best engineers in what they do first. Here's one YouTube video of 5 Tesla executives talking about the engineering of Cybertruck from design, materials, manufacturing, powertrain, electronics and software with Sandy Monroe and you'll notice they don't talk or carry themselves around like VPs or directors at any other automotive or technology companies.

Paul started at Tesla as an engineer and spearheaded Giga Casting, which is a great example of materials engineers (metallurgists) and design engineers working on the same team for a part/process that didn't exist.

Paul talked really fast and only had a minute or two for my answers. Shortly after half way into the call, he wanted me to ask him questions. I asked about his vision for the Materials Applications Engineering team and where he expected the team to be in 2 to 3 years. I also asked how he convinced suppliers to design the presses required for Giga Casting. Again, his answers were short and we finished our call exactly at 30 minutes.

I felt the call didn't go well and wrote an email to Matt and Dave in the evening, apologizing that I might have messed up and thanked them for the trust and support for nearly three months from September 30th to December 22nd.

The End

It was until January 14th, 2022 when I received the confirmation that Paul decided to send my offer in for Charles Kuehmann and Elon's review. Between January and April 2022, there was a round of layoff that impacted many teams, including the Materials Engineering team, followed by a hiring freeze. It was until after my rotation across three factories in Fremont and Gigafactory Nevada as part of my onboarding training when I learned that as soon as the hiring freeze started to thaw, Dave managed to secure the offer with sponsorship from Colin Campbell who was leading Powertrain Engineering and would be the customer of the project he had in mind for me.

On May 31st, 8 months after I submitted my application, I started as Staff Design Engineer at Tesla Materials Engineering, embarking on a new journey filled with challenges and breakthroughs every other week.