Mercury Internship 2027–2028: Programs, Deadlines & How to Apply

Last updated: July 2026

Mercury hired 16 Haskell interns for Summer 2026, its largest cohort to date, up from just 5 in Fall 2024. The company runs one of the only production Haskell backends in fintech, which naturally filters the applicant pool and creates a narrower, less crowded path to an offer than mainstream-language competitors. For the 2027–2028 cycle, applications are expected to open in September or October 2026 and close by mid-October, giving you a window measured in weeks, not months.

Quick Facts

Mercury's Haskell tech stack is both the barrier and the advantage: fewer applicants compete for each seat because the language filters out the mass-apply crowd. Cohorts range from 5 to 16 interns, applications close in roughly three weeks, and the entire process from application to offer averages about 14 days.

Externships are short, remote projects where you finish real work for a real company. The Wayfair AI Agent Engineering Externship and Beats by Dre Data Analytics Externship build the engineering craft, code review ability, and data analysis evidence a Mercury application and its take-home interview reward. Explore all Externships.

What Is a Mercury Internship?

A Mercury internship is a paid, fully remote, 12- to 16-week placement where students build production features for a banking platform serving over 100,000 businesses. Mercury is one of the rare companies running a 100% Haskell backend in production, and interns contribute directly to that codebase from their first week, building features for customers, improving internal developer tools, or strengthening operational systems. The company provides a structured Haskell curriculum for newcomers to the language, so prior Haskell experience is helpful but not required. With three cohorts per year (fall, spring, summer) and cohort sizes ranging from 5 to 16 interns, Mercury offers an unusually small-team, high-mentorship environment. Return internship offers and full-time conversion offers are extended to strong performers, making each cohort a direct pipeline into a company valued at over $3.5B and backed by Y Combinator and Andreessen Horowitz.

When Do Mercury Internship Applications Open for 2027–2028?

Mercury's internship calendar follows a tight, cohort-based pattern rather than continuous rolling review. For the Summer 2026 cycle, postings went live in fall 2025 and the application window closed on October 17, 2025. Interviews ran through November and December, and the average time from application to hire was approximately 14 days according to Glassdoor data. The Summer 2027 cycle is expected to follow the same rhythm, shifted forward by one year. Mercury also runs spring and fall cohorts, so if you miss the summer window, two more entry points appear during the academic year.

Why You Must Apply the Week Applications Open

Mercury's application window is one of the shortest in fintech. The Summer 2026 cycle closed on October 17, 2025, roughly three to four weeks after postings went live. With cohort sizes of 5 to 16 interns and an average application-to-hire timeline of just 14 days, the process moves fast and seats fill quickly. The Haskell tech stack helps you here: because most applicants self-select out when they see functional programming as a requirement, the remaining pool is smaller and more specialized. That means willingness to learn Haskell, even without deep experience, is itself a signal. Apply the day the posting appears, and spend the weeks before the window opens building a basic Haskell project or completing Mercury's recommended learning resources, so your application lands with evidence rather than just enthusiasm.

Which Mercury Internship Programs Should You Target?

Mercury runs three cohorts per year, each placing interns directly onto product teams building a banking platform for over 100,000 businesses. The backend is 100% Haskell, which makes the engineering tracks distinctive among fintechs. Cohort sizes range from 5 to 16 interns, with the summer cohort being the largest. Which track should you target? If you have functional programming interest, backend is the primary lane. If TypeScript and React are your strengths, frontend roles open in most cycles.

See open roles on mercury.com/jobs. Note that Mercury does not maintain a permanent internship landing page; postings appear seasonally. The lifeatmercury.com/interns page provides intern-specific details for candidates with scheduled interviews.

What Are the Eligibility Requirements?

Mercury's requirements reflect a company that values craft and curiosity over checkbox credentials:

• Enrollment: must be enrolled in an academic program (undergraduate or graduate). Individuals not enrolled are encouraged to apply to full-time openings instead.

• Haskell: working knowledge of or willingness to learn Haskell is required for backend and full-stack roles. Mercury provides a structured Haskell curriculum for newcomers, and past interns confirm it is sufficient to get productive.

• TypeScript: required for frontend roles. React experience is a plus.

• Work authorization: must be eligible to work in the US or Canada. Visa sponsorship is not explicitly confirmed or denied in available sources. Do not confuse Mercury (banking fintech) with Mercury Insurance, a different company.

Do I Really Need to Know Haskell Before Applying?

No. Mercury explicitly accepts willingness to learn. A former Summer 2022 intern noted that the Haskell curriculum provided for newcomers was sufficient to follow and contribute to real projects within the first weeks. That said, having even a basic Haskell project on your resume signals genuine interest and reduces ramp-up time. The functional programming requirement naturally filters out mass-apply candidates, which works in your favor if you invest even modest time learning the fundamentals before the window opens.

What Skills Does Mercury Look For, and How Do You Build Them?

Read across four Mercury intern job descriptions, two backend Haskell, one frontend TypeScript, and one product design, and the pattern centers on craft over credentials. Communication and the ability to explain technical reasoning appear in all four. Haskell or functional programming appears in three, TypeScript in two, and SQL in two. But Mercury's JDs are unusually explicit about what they value beyond technical skill: curiosity, willingness to share perspective, and appreciation for quality in your own work and that of others. The interview process tests these values directly through a code review discussion built into the take-home project.

How Is Demand for Software Engineering Interns Moving Right Now?

Build These Skills Before You Apply

And every skill in that chart maps to a remote Externship where you finish a real project before a role opens.

The Wayfair project is engineering work that produces the code-quality and explanation evidence Mercury's take-home code review discussion directly probes, and the Beats project yields the SQL and data-analysis story the PR review stage rewards.

What Is the Mercury Application and Interview Process Like?

Mercury's interview process is notably lean, averaging about 14 days from application to offer according to Glassdoor data:

1. Apply on mercury.com/jobs. Internship postings appear seasonally. Apply as soon as the summer posting goes live; the application window is typically three to four weeks. Employee referrals account for a third of hires according to Glassdoor interview data.

2. Recruiter screen. An introductory call covering background, motivation, and fit. Come prepared with questions about the business, because Glassdoor reviewers note that faltering here leaves a poor impression.

3. SQL PR review. A technical assessment where you review and refactor the database schema of a pull request. This tests both your SQL knowledge and your code review ability, a core skill Mercury evaluates throughout the process.

4. Take-home coding project (3 hours). A structured session: 15 to 30 minutes of an engineer explaining the parameters, 2 hours of coding time, then 40 minutes of code review discussion with the engineer. The discussion matters as much as the code itself.

5. Team matching conversation. Not an evaluation round; a placement discussion about which team aligns with your goals and interests. Mercury's small cohort sizes (5 to 16) mean team fit is taken seriously.

Two things to drill. First, SQL fluency: the PR review is the earliest technical gate, and it tests refactoring judgment, not just query syntax. Second, the ability to explain your reasoning clearly and accept feedback during the take-home code review discussion, because Mercury's JDs explicitly value communication and quality appreciation. Haskell experience helps but is not required for the interview loop; the take-home is not Haskell-specific.

What Students on Reddit Say

Three community threads show the program from the inside, all paraphrased.

How Do You Stand Out When the Window Is Three Weeks?

Three moves, all before the posting goes live. First, learn Haskell basics now: even a small functional-programming project on your resume signals genuine interest and separates you from the mass-apply crowd that bounces at the language requirement. Mercury provides a curriculum for newcomers, but arriving with fundamentals already in place shortens ramp-up and strengthens your application. Second, sharpen your SQL and code review skills: the first technical gate is a PR review where you refactor a database schema, and the take-home ends with a 40-minute code review discussion. Practice reading and critiquing others' code, not just writing your own. Third, apply the day the posting appears and, if possible, secure an employee referral: Glassdoor data shows referrals account for a third of Mercury hires, and the application window historically closes in three to four weeks.

What Other Companies Should You Consider?

Mercury is not the only fintech offering remote internships with strong engineering cultures. If you are building a fintech internship list, these are the natural neighbors:

Our tech internships summer 2027 guide maps the whole landscape, timeline by timeline.

FAQ

Do I need to know Haskell before applying to Mercury?

No. Mercury explicitly accepts willingness to learn and provides a structured Haskell curriculum for newcomers. Past interns have confirmed it is sufficient to get productive on real projects within the first weeks. That said, even a basic Haskell project on your resume signals genuine interest and reduces ramp-up time.

How much do Mercury interns get paid?

Mercury pays $55 per hour in the US (approximately $9,533 per month) or CAD 55 per hour in Canada. NYC interns also receive a $7,000 one-time housing stipend. Additional perks include a $100 per week food budget, $50 per month phone reimbursement, and full tech equipment including laptop, monitor, keyboard, and mouse.

Is Mercury's internship remote?

Yes. Mercury internships are fully remote in the US or Canada. Optional offices are available in San Francisco, New York City (with housing stipend), Portland, and Toronto. You choose where you work.

When should I apply for Mercury's summer 2027 internship?

Based on the Summer 2026 pattern, applications are expected to open in September or October 2026 and close by mid-October. The Summer 2026 application closed October 17, 2025. The average time from application to hire is about 14 days, so the process moves fast.

Does Mercury offer return offers or full-time conversion?

Yes. Mercury makes both return internship offers and full-time offers to strong performers. The process is performance-based and not guaranteed. No specific conversion rate is publicly available. Mercury runs three cohorts per year (fall, spring, summer), providing multiple on-ramp opportunities.

How competitive is Mercury's internship?

Mercury appears in both the finance and fintech and startups tiers on community internship rankings. Cohort sizes range from 5 to 16 interns per cycle. The Haskell tech stack naturally filters the applicant pool, potentially reducing raw application volume compared to companies using mainstream languages.

What is Mercury's interview process like?

A recruiter screen, a SQL PR review (refactoring a database schema), a 3-hour take-home coding project with a 40-minute code review discussion, and a team matching conversation. Glassdoor rates the interview difficulty at 2.7 out of 5 (average) with 71% positive experience. The average time from application to hire is about 14 days.

Mercury's application window closes in weeks, not months, and the Haskell requirement filters out most of the mass-apply crowd. Spend the runway building proof: a remote Externship turns 'willing to learn Haskell' into a deployed project that signals engineering craft before the posting goes live.