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Express and MongoDB Backend Engineering Intern

MailerMen

Actively hiring🇮🇳 Pune, IndiaHybridInternship₹14K – ₹18K /mo0 yrs expFull Stack Developer
Posted 2d agoBe an early applicant

What this role pays, in context

This listing pays 14% above the median for Full Stack Developer roles in India, which sits at ₹14K a month.

25th pct ₹12.8K75th pct ₹15.4K

Median of 12 other live Full Stack Developer listings in India on this board that state pay. Roles that do not disclose a salary are excluded rather than counted as zero.

Why this role exists

If you would rather be behind the API than in front of it, this is the seat. MailerMen runs a single Express service that every client talks to, and it has grown faster than its structure. Across six months you will help split it into clear modules and harden the parts that carry the most traffic.

The work itself

You start on the applications API, where a candidate applying to a role currently triggers four separate writes and no transaction. You will move that into one MongoDB transaction, add idempotency so a double tap does not create two applications, and write the tests that prove it. Later you take on rate limiting for our public endpoints, a Mongoose aggregation pipeline that powers employer reporting, and index tuning for a collection that has crossed two million documents.

What we will teach you

How to read a slow query plan. When denormalising is correct and when it is laziness. How to write an error response a frontend developer can act on. You will be in the Pune office three days a week, sitting next to the people whose code you are changing.

Responsibilities

  • Refactor the applications API into a single MongoDB transaction with idempotency keys
  • Add rate limiting and request validation to public Express endpoints
  • Write Mongoose aggregation pipelines that power employer reporting
  • Profile slow queries with explain plans and add or reshape indexes
  • Cover every route you touch with Jest and Supertest tests
  • Document each endpoint in our OpenAPI spec as you go
  • Take part in the weekly backend design discussion

Requirements

  • Final year student or graduate of any year, no prior professional experience required
  • You have written server side JavaScript before, even for a hobby project
  • You understand what a database index is and why it matters
  • Able to attend the Pune office three days a week
  • Willing to write tests, not only code that works on your machine

Skills

Benefits

  • Ownership of production endpoints rather than sandbox exercises
  • Weekly backend design sessions where you are expected to speak
  • A mentor assigned to you for the full six months
  • Completion certificate and a written performance reference
  • Priority consideration for our full time backend openings