Your first 90 days in a new job: what to do week by week

Nobody says this at the offer stage, but the first three months of a job are a second interview. Your manager is quietly checking whether the hire was right. Your new colleagues are deciding whether you are going to be useful or a drain. And you, whether you admit it or not, are working out whether you made a mistake.

The good news is that this period is short, fairly predictable, and mostly within your control. What follows is a plan for week 1, weeks 2 to 4 and weeks 5 to 12, the questions worth asking your manager in the first fortnight, how to find the rules nobody writes down, and the small early mistakes that people are still paying for a year later.

Before day one

Two things are worth doing in the gap between accepting and starting. First, re-read the job description and any notes from your interviews, and write down what you think the job is for. Not the tasks, the purpose: “hired to stop the support backlog growing” or “hired because the last analyst left and the monthly reporting stopped.” You will test that theory against reality in week one, and the gap between the two is where most early trouble lives.

Second, sort the logistics so they do not eat your first morning: start time, where to go or which link to join, what identification you need. If you are starting remotely, ask whether the laptop will arrive before day one. It often does not.

Week 1: listen, write things down, get access sorted

The first week has one job: absorb. You are not there to fix anything yet, and anyone who tries usually fixes the wrong thing.

Keep a running document from the first hour. Names, roles, who reports to whom, which acronyms nobody explained, which systems you need access to and who grants it. Chasing access is unglamorous but it decides how fast you become useful, so make a list of every login and permission you are missing by Wednesday and send it to your manager or the onboarding contact in one message rather than dribbling requests out over a fortnight.

Ask for introductions, and go to them prepared. A useful opener for each person is short: what do you work on, where does your work touch mine, and what do you wish the person in my role had done differently? That last question is gold. People will tell a newcomer things they would never say in a meeting.

Book a proper one-to-one with your manager for the end of week one if one is not already in the diary. That is where the questions in the section below belong.

One more thing for week one: work out the daily rhythm. When do people actually start? Do they eat lunch at their desks? Does the team chat go quiet after 5:30 or carry on until 9? You do not have to copy every habit, but you need to know what the default is before you decide where you will differ from it.

Weeks 2 to 4: learn how the work actually gets done

By the second week you should be doing real tasks, ideally small ones that finish. Ask for them if they do not arrive. A manager who is too busy to onboard you properly will still respond well to “Is there something small I can take off your plate this week so I can learn the process end to end?”

Use these weeks to map the informal system. Every organization has an official process (the wiki, the handbook, the flowchart from 2019) and a real one (Priya in finance approves it if you message her directly; the Friday report is read by exactly one person). You find the real one by watching what experienced colleagues do rather than what the documentation says, and by asking “how does this usually go?” rather than “what is the process?”

This is also when you should start to understand who your manager’s manager is and what they care about. You will rarely deal with them directly, but their priorities set your manager’s priorities, which set yours.

Pace yourself on opinions. You will notice things that look wrong. Some of them are wrong. Others are the scar tissue from a problem you have not encountered yet. A safe rule for the first month is to ask why something is done the way it is before suggesting a change, and to save your suggestions for a moment when someone asks for them. Most managers ask for a fresh pair of eyes at around the 30-day mark; that is the time to spend the credibility you have been building.

The questions to ask your manager

Ask these in your first one-to-one, or spread them over the first two. Write the answers down and revisit them at day 90.

1. What would make you say, in three months, that hiring me was the right call? You want a concrete answer. If you get a vague one, ask what the first thing is they would like off their desk.
2. What is the one thing I could get wrong early that would be hard to recover from? Managers usually have a clear view of this and rarely volunteer it.
3. How do you prefer to get updates: a weekly written note, a quick message when something changes, or only when there is a problem?
4. Who should I get to know in the first month, and is there anyone I should be careful around?
5. What does the team’s calendar look like over the next quarter? Any deadlines, launches or budget rounds that are going to shape my first few months?
6. How is performance reviewed here, and when is my probation reviewed? (In the UK, Canada and Australia a probation period will usually be in your contract. In the US it is often informal, but the 90-day mark is still a common checkpoint.)

The update-preference question deserves a second mention. Much early friction between a new hire and a manager is simply a mismatch in how much communication each expects. Ask, then over-communicate slightly until you have calibrated.

Finding the unwritten rules

Every workplace runs on rules that nobody writes down, and new hires break them in the first month because nobody warned them. Some patterns to look for:

• Who really decides. The org chart says one thing; the meeting where the decision actually gets made may be an informal chat between two people on Thursday afternoons. Watch whose opinion changes the outcome.
• What “urgent” means here. In some teams every message is urgent and none of them are. In others, a direct message means drop everything. Ask a peer, not your manager, how they read it.
• The tone of writing. Read a few weeks of old messages or emails in the channels you have joined. Is it terse and bullet-pointed, or warm and chatty? Match it.
• Meeting etiquette. Cameras on or off, whether you can decline invitations, whether people speak up or wait to be asked. Get this wrong and you look either arrogant or invisible.
• The sacred cows. Every organization has a product, a process or a person that is not up for criticism, at least not from the new person. Find out early.

The most reliable way to learn these is to find one colleague at your level who has been there a year or two and is willing to be candid. Buy them a coffee, in person or virtually, and ask: “What do I need to know that is not in the handbook?”

Weeks 5 to 12: deliver something and set the pattern

Somewhere in month two you should ship something visible. It does not need to be big. A cleaned-up report, a fix to a process everyone hated, a piece of work that landed on time without drama. The point is to give your manager a concrete example to point at when someone asks how the new hire is doing.

Choose that first deliverable carefully. Ideally it is something your manager has mentioned more than once, is achievable with the access and knowledge you already have, and has a clear finish line. Do not pick the sprawling, political problem nobody has solved in three years. That one can wait until you have allies.

This is also when your working pattern sets. The hours you keep, how quickly you reply, whether you take a real lunch, whether you say yes to everything: these become expectations by the end of the quarter and are much harder to change later. If you intend to protect your evenings, protect them from week five, not from month six. The same goes for workload; if you find yourself agreeing to every request, our guide to saying no at work without damaging your reputation is worth reading before the habit forms.

Toward the end of the period, ask for feedback explicitly. “Is there anything you would like me to do differently in the next quarter?” is a question managers appreciate and rarely get. Ask it in week 10 or 11, so there is still time to adjust before any formal review.

Early mistakes that stick

A few errors have a reputation cost far larger than they deserve, mostly because they happen when people have no other data on you.

• Comparing everything to your old job. “At my last place we did it like this” is fine once. By the fifth time, colleagues stop listening. Save comparisons for when someone asks.
• Going over your manager’s head. Even with good intentions, taking a problem to their boss in the first three months reads as a lack of trust. Raise it with your manager first, every time.
• Missing the first deadline. Nobody expects brilliance from a new hire, but they do expect reliability. If a date is going to slip, say so early. The slip is forgiven; the surprise is not.
• Oversharing in the first week. Your views on the previous employer, your salary, your job-hunting, your health, your politics. Colleagues you have known for three days are not yet friends.
• Committing in writing to something you do not understand. If you are asked to sign off on a plan or a number in your first month, ask for a day to review it. Nobody reasonable will object.
• Disappearing. Remote starters in particular can become invisible. If you work from home, be deliberately present: turn up to optional calls, reply promptly, post a short weekly note on what you did.

None of these are fatal on their own. The problem is that in the first 90 days they are the only story people have about you.

What good looks like at day 90

By the end of the quarter, a reasonable target is this: your manager can name one thing you delivered, you know who actually makes decisions in your area, you have one or two colleagues who will tell you the truth, and you have a clear answer to the question you asked in week one about what a successful hire looks like.

If you are well short of that, do not panic, but do have a direct conversation with your manager about what is getting in the way. And if the job turns out to be materially different from what was described at interview, the 90-day mark is a legitimate time to raise it, including pay and scope, rather than letting it drift. Our guide to negotiating salary for a new job covers what to do when the role has grown since you accepted it.

The single most useful habit from all of this is the running document. Keep it going past day 90. It becomes the raw material for your first review, your first raise request, and eventually your next resume.