First 90 Days in a New Developer Job: Checklist

What this checklist is

A practical checklist for your first 90 days as a software developer in a new job. It covers preparing before day one, getting access and a working setup in week one, shipping a first small change, learning how work is planned and reviewed, working with your manager, and asking for feedback at day 30, 60 and 90.

It has 7 chapters and 32 checks, each with how to verify it and how much it matters. For new hires, interns and fresh graduates.

Chapter by chapter

1. Before day one and week one: access, setup and people (5 checks)

Get the logistics out of the way, get a working development setup, and meet the people you will work with most.

2. Learn the codebase and ship a first small change (6 checks)

How to build a mental map of the system and get a small, real change reviewed and merged in your first weeks.

3. How work is planned, reviewed and shipped (4 checks)

Learn the team process around the code: planning, definitions of done, code review and deployment.

4. Your manager, 1:1s and expectations (4 checks)

How to set clear expectations with your manager and use 1:1s well from the first week.

5. Document what you learn and ask good questions (5 checks)

Keep notes that save you and the next new hire time, and ask questions that are fast to answer.

6. Feedback at day 30, 60 and 90 (4 checks)

Ask for feedback on purpose at three points instead of waiting for a formal review.

7. Common early mistakes to avoid (4 checks)

Mistakes new developers often make in their first months, and what to do instead.

How it works on Sefism

The checklist is one page: each check has a severity (must, should or nice to have) and a concrete way to verify it, and members can tick checks off as they go. The opening chapters are open to everyone. Adding it to your account uses credits, opens every chapter and keeps your progress.

Every claim is checked against the sources listed on the page (6 cited).