7 Highly Profitable (and Scaleable) Side Hustles for Engineers

woman, adult, people-3261425.jpg

This post is based on my experience trying out multiple side hustles as an engineer. I will give you my best take, what has worked for me best, and I will let you know to stay away from others that do not have much upside for the time or money they require.

If you are an engineer looking to unlock new avenues of income and financial freedom beyond your 9-5 job, my friend, let me tell you you’re not alone. 

Many engineers, myself included, seek to leverage their skills and expertise to build profitable side hustles and create a life of abundance and fulfillment.

So given this is a question that comes up over and over, we are going to explore the top seven side hustle options that are not only lucrative but also scalable, you can start with zero dollars, and if done well, it may allow you to eventually transition from your corporate job to entrepreneurship.

Disclaimer on affiliates: This page contains some affiliates. This means that if you click on a link, I may receive a small commission . It helps keep the content free and helpful, and support the blog! 🙂


Before we get started, let’s get on the same page. 

If you’re anything like me, you’ve noticed that not all side hustles are made equal. There are side hustles that require lots of time and effort for very little payout (think of surveys, ride sharing, food delivery, etc.). Personally, I’ve tried some of these, and while they had their place in the past, they are no longer good options in my personal opinion.

That’s why I decided to come up with my own requirement for side hustle (a small business you set up on the side in addition to your full time job):

  • It can be done after work and when my family goes to sleep (AKA from 9 to 11 PM)
  • It can be done in two-hour increments
  • From home
  • Highly profitable
  • Scalable 
  • Low to zero up-front investment of time and/or money to start

With this in mind, let’s get started.

By the way, if you are an engineer or professional who wants to build side income on the side, contact me here at alex@alexisidro.com

1. Freelancing Engineering Services

Freelancing involves offering your engineering expertise and services on a contract basis to clients or businesses in need of technical assistance.

Pros of Freelancing in Engineering Services

  • Utilize your engineering skills and knowledge to provide valuable services.
  • Flexibility to choose your projects, clients, and work hours.
  • Potential for high hourly rates, especially for specialized skills.
  • Opportunity to build a portfolio and reputation in your industry.

Cons of Freelancing in Engineering Services​

  • Requires self-promotion and marketing to attract clients initially.
  • Income may fluctuate based on project availability and demand.
  • Need to manage client relationships, project deadlines, and administrative tasks.

How to Get Started with Freelancing in Engineering Services

  • Identify your niche or specialization within engineering services.
  • Create a professional website or portfolio showcasing your skills, expertise, and past projects.
  • Join freelancing platforms such as Upwork, Freelancer, or Fiverr to find clients and projects.
  • Network with industry professionals and attend relevant events to expand your client base.
  • Deliver high-quality work and exceed client expectations to build a positive reputation.

How to Scale Freelancing in Engineering Services

  • Expand your service offerings to cater to a broader range of clients or industries.
  • Hire subcontractors or build a team to handle increased workload and projects.
  • Invest in marketing and branding to attract higher-paying clients and larger projects.
  • Develop strategic partnerships with complementary businesses or agencies to access new markets or opportunities.

2. Affiliate Marketing (Engineering Tools, Software, or others)

This is by far one of my favorite side hustles out there. 

It’s the one I do the most; no clients I have to deal with, no questions from customers, and it all comes down to making valuable and helpful content to help people make better financial and business decisions. 

Affiliate marketing involves promoting products or services offered by other companies and earning a commission for every sale or referral made through your unique affiliate link.

Pros of Affiliate Marketing

  • No need to create or own products; simply promote existing products or services.
  • Access to a wide range of engineering tools, software, and resources to promote.
  • Passive income potential, as you earn commissions on sales generated through your affiliate links.
  • Scalable business model with the ability to reach a global audience.

Cons of Affiliate Marketing

  • Requires effective marketing and promotional strategies to drive traffic and sales.
  • Need to disclose affiliate relationships and maintain transparency with your audience.
  • Income may vary based on product popularity, commission rates, and market trends.

How to Get Started with Affiliate Marketing

  • Choose a niche or segment within engineering (e.g., CAD software, electronics components, mechanical tools).
  • Research and identify reputable affiliate programs and products relevant to your niche.
  • Create valuable content such as product reviews, tutorials, or comparison guides on your blog or social media channels.
  • Include affiliate links within your content and disclose your affiliate relationships to comply with regulations.
  • Promote your content through SEO, social media, email marketing, and other channels to attract targeted traffic.

How to Scale Your Affiliate Marketing Business

  • Expand your product offerings by partnering with multiple affiliate programs or networks.
  • Create evergreen content that continues to generate passive income over time.
  • Build an email list and engage with your audience through regular newsletters and promotions.
  • Explore paid advertising options such as Google Ads or social media ads to scale your reach and exposure.
  • Collaborate with influencers or industry experts to increase your visibility and credibility.

3. Online Course Creation

Online course creation involves developing and selling digital courses that teach specific skills, techniques, or knowledge to a targeted audience.

The cool thing about online courses is anyone can create one. You just need to be able to solve a big enough problem your audience will be willing to pay for it. 

Pros of Online Course Creation

  • Share your expertise and knowledge with a global audience.
  • Passive income potential, as courses can be sold repeatedly without additional effort.
  • Flexibility to create courses on topics of interest or demand within your niche.
  • Establish yourself as an authority and thought leader in your field.

Cons of Online Course Creation

  • Requires time and effort to plan, create, and market high-quality courses.
  • Need to invest in course hosting platforms, technology, and marketing tools.
  • Competition from existing courses and platforms within the engineering education space.
  • Continuous updates and maintenance to keep courses relevant and valuable.

How to Get Started with Online Course Creation

  • Identify a specific engineering skill or topic that you are knowledgeable and passionate about teaching.
  • Research and validate the demand for your course idea through keyword research, surveys, and competitor analysis.
  • Plan and outline your course content, including lectures, assignments, and supplementary materials.
  • Choose a platform for hosting your course, such as Udemy, Teachable, or Thinkific.
  • Create engaging and high-quality course content using multimedia formats like video lectures, quizzes, and interactive exercises.

How to Get Scale Your Online Course Business

  • Expand your course catalog by creating multiple courses covering different aspects or levels of expertise within your niche.
  • Offer advanced or premium courses with additional features, resources, or personal coaching.
  • Partner with other experts or influencers to co-create courses or cross-promote each other’s content.
  • Launch membership or subscription-based models to provide ongoing value and recurring revenue.
  • Invest in marketing and advertising to reach a broader audience and drive sales for your courses.

4. Digital Product Creation in Engineering Resources

Digital product creation involves developing and selling digital resources, templates, or tools designed to help engineers improve their productivity, efficiency, or skills.

This can be calendars, notion templates, photography presents, e-books, etc. Don’t feel held back by your engineering expertise. If you see opportunity somewhere else beyond engineering, don’t be afraid to go for it! 

Pros of Building Digital Products

  • Create passive income streams by selling digital products online.
  • Offer valuable resources and tools that solve specific problems or pain points for engineers.
  • Low overhead costs compared to physical products or services.
  • Scalable business model with the ability to reach a global audience.

Cons of Building Digital Products

  • Requires upfront investment of time and effort to create high-quality digital products.
  • Need to continuously update and improve products based on customer feedback and market trends.
  • Competition from existing digital products and resources in the engineering industry.
  • Limited income potential compared to services or courses with recurring revenue.

How to Get Started with Building Digital Products

  • Identify common challenges or needs faced by engineers in your niche.
  • Brainstorm ideas for digital products or resources that address these challenges or provide solutions.
  • Create prototypes or samples of your digital products using design software or tools.
  • Validate your product ideas through market research, surveys, and feedback from your target audience.
  • Develop and finalize your digital products, ensuring they are well-designed, user-friendly, and valuable to your customers.

How to Scale Your Digital Product Business

  • Expand your product line by creating additional digital resources or tools that complement your existing offerings.
  • Offer customizable or premium versions of your digital products with enhanced features or functionalities.
  • Establish partnerships or collaborations with industry experts or influencers to co-create products or promote each other’s offerings.
  • Create affiliate programs to incentivize others to promote and sell your digital products.
  • Invest in marketing and advertising to increase awareness and reach new customers for your digital products.

5. Content Creation and Monetization on Social Media

Digital product creation involves developing and selling digital resources, templates, or tools designed to help engineers improve their productivity, efficiency, or skills.

Pros of Content Creation and Monetization on Social Media

  • Showcase your expertise, personality, and insights to a global audience.
  • Build a loyal community of followers and fans who resonate with your content and message.
  • Multiple monetization opportunities, including ads, sponsorships, affiliate marketing, and product sales.
  • Flexibility to create content in different formats, such as videos, podcasts, articles, or live streams.

Cons of Content Creation and Monetization on Social Media

  • Requires consistent effort and dedication to produce high-quality content and engage with your audience regularly.
  • Need to navigate platform algorithms, trends, and policies to maximize visibility and reach.
  • Competition from other content creators and influencers within your niche or industry.
  • Income may fluctuate based on factors like audience size, engagement rate, and monetization strategies.

How to Get Started:

  • Choose social media platforms that align with your content format and target audience preferences (e.g., YouTube for videos, LinkedIn for professional networking).
  • Define your content niche, voice, and branding to differentiate yourself from other creators.
  • Plan and create engaging content that provides value, educates, entertains, or inspires your audience.
  • Optimize your content for each platform’s algorithms and best practices to increase visibility and engagement.
  • Explore monetization options such as ads, sponsorships, affiliate marketing, and merchandise sales to generate income from your content.

How to Scale

  • Diversify your content formats and topics to appeal to a broader audience and attract new followers.
  • Collaborate with other creators, brands, or influencers to cross-promote content and reach new audiences.
  • Invest in equipment, software, and resources to improve the quality and production value of your content.
  • Offer premium or exclusive content through membership or subscription models to monetize your loyal fan base.
  • Analyze data and insights from social media analytics to optimize your content strategy and maximize ROI.

6. E-commerce in Engineering Products or Merchandise

E-commerce involves selling physical or digital products related to engineering, such as equipment, tools, gadgets, or merchandise, through online platforms or your own e-commerce store. I’ve always had this idea of selling Heating, Ventilation & Air Conditioning units; buying them overseas and selling them here in the USA. 

The reason I haven’t done it is because it’s not a passion of mine. I couldn’t care less about HVAC systems (yes, even as a mechanical engineer myself lol). But it could be for you! 

Pros of E-Commerce for Engineers

  • Tap into the growing demand for engineering-related products and merchandise.
  • Reach a global audience of engineers and enthusiasts through online sales channels.
  • Opportunities to create and sell unique or niche products tailored to specific engineering disciplines or interests.
  • Scalable business model with the potential for recurring sales and customer loyalty.

Pros of E-Commerce for Engineers

  • Requires investment in inventory, manufacturing, fulfillment, and logistics infrastructure.
  • Competition from established e-commerce platforms and engineering suppliers.
  • Need to invest in marketing and advertising to attract traffic and customers to your online store.
  • Management of inventory, order fulfillment, and customer service can be time-consuming and complex.

How to Get Started

  • Research and identify popular or trending engineering products, gadgets, or merchandise with high demand.
  • Source suppliers or manufacturers for your products, ensuring quality, reliability, and competitive pricing.
  • Create an e-commerce store using platforms like Shopify, WooCommerce, or Amazon Seller Central to showcase and sell your products.
  • Develop a branding and marketing strategy to differentiate your products and attract customers through SEO, social media, email marketing, and advertising.
  • Optimize your e-commerce operations for efficiency, scalability, and customer satisfaction, including inventory management, order processing, and shipping logistics.

How to Scale

  • Expand your product catalog by adding new items, variations, or accessories to cater to different customer preferences and needs.
  • Explore international markets and partnerships to reach a broader audience and increase sales potential.
  • Invest in branding, packaging, and customer experience to enhance your brand reputation and loyalty.
  • Implement automation and technology solutions to streamline your e-commerce operations and scale efficiently.
  • Launch promotional campaigns, sales events, or exclusive offers to incentivize repeat purchases and customer referrals.

7. Consulting and Coaching in Engineering Career Development

Consulting and coaching involve offering personalized advice, guidance, and support to engineers seeking to advance their careers, transition to new roles, or pursue entrepreneurship.

This is something I currently do and I love it. If you are interested in online business, entrepreneurship, help people get to where you are, and simply share your lessons. Help them go from A to B and everyone will win. 


  • Leverage your expertise and experience to help others achieve their career goals and aspirations.
  • Flexible business model with opportunities to offer one-on-one coaching, group workshops, or online courses.
  • High-value service offering with the potential for premium pricing and recurring revenue.
  • Fulfilling and rewarding work, as you empower engineers to unlock their full potential and achieve success.


  • Requires strong interpersonal skills, communication, and empathy to effectively coach and mentor clients.
  • Need to establish credibility, trust, and authority in your field to attract clients and command premium rates.
  • Time-intensive nature of consulting and coaching engagements, including client meetings, assessments, and follow-ups.
  • Challenges in balancing client commitments with other business or personal responsibilities.

How to Get Started:

  • Define your consulting or coaching niche within engineering career development, such as leadership coaching, resume writing, interview preparation, or entrepreneurship mentoring.
  • Showcase your credentials, experience, and success stories to establish credibility and attract potential clients.
  • Develop a range of coaching programs, services, and packages tailored to different client needs and budgets.
  • Market your consulting services through networking, referrals, speaking engagements, and online platforms like LinkedIn or industry forums.
  • Offer free consultations or introductory sessions to showcase your value and expertise to prospective clients.

How to Scale:

  • Create scalable coaching programs or online courses that can serve multiple clients simultaneously.
  • Hire additional coaches or consultants to expand your capacity and reach more clients.
  • Develop digital products or resources (e.g., e-books, webinars, templates) to complement your coaching services and generate passive income.
  • Establish partnerships with corporations, universities, or professional associations to offer coaching programs or workshops to their employees or members.
  • Invest in marketing and branding to position yourself as a leader in your niche and attract high-value clients and opportunities.


As an ambitious engineer with a desire to create additional income streams and achieve financial freedom, you have several lucrative and scalable side hustle options to explore. 

Whether you choose to freelance in engineering services, create online courses, or monetize your social media presence, each side hustle offers unique opportunities for growth and success.

By leveraging your engineering background, analytical skills, and passion for personal development, you can overcome challenges, embrace opportunities, and build a thriving online business that aligns with your goals and aspirations.

Remember, success doesn’t happen overnight, but with dedication, persistence, and the right strategy, you can turn your side hustle into a rewarding and fulfilling venture. 


Should all engineers have a side hustle?

In this day and age, I absolutely believe every engineer should have a side hustle. Not only does this decrease the risk of no income if you get laid off (let’s be honest, this could happen to any of us), a side hustle can also help you reach your financial and personal goals faster. 

Whether you are trying to save for a wedding, for your next house, for your car, or even for a vacation, a side hustle can help turbocharge your income and reduce the time it takes to reach your goals. 

What if my job finds out I have a side hustle?

So be it. As long as you are not doing anything that entails selling your company’s information, or hurting other people, or sharing controversial content or getting into questionable business practices, you might be surprised how much people just don’t care. You could also keep in the dark if you establish your side hustle from behind the scenes; that is, you become a producer and mastermind as opposed to you doing all the work showing your face. The business models out there are endless. You don’t have to show your face. 

Will making content online ruin my career?

Technically, no. But I guess you could say it depends on what kind of content. As I mentioned previously, the way I personally see it is if you are helping people, and are making a positive difference in the world, people won’t mind. In fact, they might ask you questions on how you did it. 

Lastly, creating content online can help your career as well. I saw a story of an engineering professional who was sharing everything he knew about cyber-security on LinkedIn. After a few months of doing this, he got contacted by a high profile Government organization, and BOOM! He got hired. 

It changed his life. 

Why could this NOT be you?

By the way

If you are interested in being part of a community of like-minde individuals who are all working towards financial security and financial freedom, check out the Skool community where we share tools, resources, motivation, and everything else you need to succeed and build a successful one-person online business on the side.