Full-Stack Engineering Intern - Fall 2026 at Mercury · San…

It’s 1813 and Humphrey Davy is dazzling London with scientific demonstrations and lectures. Soon enters the young bookbinder, Michael Faraday, dissatisfied with his own prospects and enamored by the mysteries of electricity. Faraday gets a break and gains an apprenticeship with Davy, and shortly thereafter (partially) blows himself and Davy up in a nitrogen trichloride explosion.

We think Davy’s sacrifice was worth it, though, since Faraday went on to do experimental work in the field of electromagnetism that is foundational to innumerable modern technologies. While we can’t promise you’ll become the next Faraday, we can promise you won’t be asked to deal with explosives on the job.

Instead, you’ll be receiving mentorship from experienced engineers, writing TypeScript and/or Haskell code, and contributing to a product that serves over 100,000 businesses. Check out demo.mercury.com to see our product for yourself.

As an Engineering Intern, you’ll join a team that aligns with your goals and interests. During the interview process, you’ll have the opportunity to talk through the various team openings.

All Engineering Interns, regardless of the specific role, should:

• Be interested in continually honing their craft.
• Have curiosity and be willing to share their perspective.
• Appreciate quality in their work and that of others.
• Communicate well, and be able to write clear explanations of their reasoning on technical decisions.

Backend Engineering Interns should have experience using the Haskell programming language, or a strong desire to learn it, and have some familiarity with SQL. In this role you can expect to:

• Collaborate with data analysts to spec and build features that draw new customers to our product.
• Provide a backend to our mobile and web frontends, to do things like search transactions or send wire transfers.
• Build admin tools to increase the efficiency of day-to-day support operations, like identifying fraudulent customers or managing accounts.
• Integrate with third-party APIs, to do things like send checks or validate SWIFT codes.

Frontend Engineering Interns should have experience with the TypeScript programming language, and experience with React is a plus. In this role you can expect to:

• Work on a beautiful app: Since many of our customers are startups, they appreciate a well-implemented design. We have high standards for our UI, and we think it shows on our website. We encourage you to sign up and check out our onboarding experience, or read our blog post about our date picker.
• Push the limits of TypeScript: As a financial technology company, preventing errors is a top priority for us, and we take advantage of TypeScript’s advanced static typing features to prevent them.
• Work in an established codebase that still has room for growth. Across 650K lines of TypeScript, we’ve built abstractions and components that will give you leverage to build great features during your months at Mercury. But there’s still a lot more to build, be it optimizing the scrolling performance of a combobox, or building whole pages to deliver a feature to customers.
• Exercise ownership over the product: Our engineers work closely with our designers and contribute their own ideas to make the product better.

Full-stack Engineering Interns should have experience using the Haskell programming language, or a strong desire to learn it, some familiarity with SQL, and experience using the TypeScript programming language. In this role, you can expect to do a combination of the frontend and backend work that is described above.

This is a paid full-time remote summer internship for 12-16 weeks between September and December. Our internship program is intended for individuals enrolled in an academic program (undergraduate, graduate, etc.). Individuals interested but not enrolled in an academic program at this time are encouraged to apply to any of our full-time openings.

In terms of compensation, the hourly rate for candidates based in the US is $55. The hourly rate for candidates based in Canada is CAD 55.

Applications close on March 6, 2026. Please apply only to the single intern position that best aligns with your qualifications and interests.

Mercury values diversity & belonging and is proud to be an Equal Employment Opportunity employer. All individuals seeking employment at Mercury are considered without regard to race, color, religion, national origin, age, sex, marital status, ancestry, physical or mental disability, veteran status, gender identity, sexual orientation, or any other legally protected characteristic. We are committed to providing reasonable accommodations throughout the recruitment process for applicants with disabilities or special needs. If you need assistance, or an accommodation, please let your recruiter know once you are contacted about a role.

We use Covey as part of our hiring and / or promotional process for jobs in NYC and certain features may qualify it as an AEDT. As part of the evaluation process we provide Covey with job requirements and candidate submitted applications. We began using Covey Scout for Inbound on January 22, 2024. 

[Please see the independent bias audit report covering our use of Covey for more information.] 

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