The Missteps That Undermine Senior Engineers at New Companies
When a senior software engineer joins a new company, there’s often an unspoken expectation, sometimes even a belief, that they will hit the ground running, level up the team, and become an influential voice from day one.
But in reality, many senior engineers end up torpedoing their own success within the first few months.
Despite having deep experience and strong resumes, some struggle to adapt to their new environment. They unintentionally alienate their teammates, push ideas that don’t land, or adopt a work style that doesn’t fit the culture. And by the time the damage becomes visible, their long-term trajectory may already be off course.
After watching this play out a few too many times, I’ve started recognizing a few common missteps that tend to sink reputations before they’ve had a chance to rise.
Mistake 1: Expecting influence without earning trust
At their previous companies, these engineers were trusted voices. Their suggestions carried weight. Their designs shaped systems. Their decisions often set direction.
But when they join a new team, none of that past trust comes with them. And yet, some act as if it should.
They challenge decisions without fully understanding the context behind them. They’re surprised when a junior engineer pushes back. In 1:1s, they vent about “not being accepted by the team” or “being met with resistance”. Meanwhile, existing team members quietly share their own frustrations: “They don’t understand how things work here!” or “They’re pushing ideas without really listening”.
At the heart of it is a simple disconnect: influence isn’t granted. It’s earned. And trust takes time. The senior engineers who succeed are the ones who listen first, ask questions, and show respect for the team's context before offering their own perspective.
Mistake 2: Copy-pasting solutions from past lives
Another common misstep is trying to replicate technical patterns from previous jobs, without asking whether they make sense in this new context.
I once worked with a senior engineer who had come from one of the FAANG companies. Early on, they proposed restructuring part of our Spring Boot app to make it more extensible for hypothetical use cases. While the design wasn’t inherently flawed, it introduced a lot of abstraction and complexity, for needs we weren’t even sure we had.
It’s a classic example of prematurely optimizing for scale or flexibility because “that’s how we did it at ABC”. But what works at a 10,000 person company doesn’t always work at a 50 person one. B2B vs. B2C, early-stage vs. mature platform — all of those differences matter.
A telltale sign is when suggestions begin with:
“At my PREVIOUSCOMPANY, we used to …”_
That phrase alone isn’t persuasive. And if not backed by a thoughtful discussion of tradeoffs, it can quickly start to erode credibility.
Mistake 3: Clinging to old work habits
Sometimes the problem isn’t technical — it’s behavioral.
In large companies, senior engineers often operate in narrower lanes. Architects may spend their time designing systems, not necessarily writing production code. On-call may be managed by a separate escalations or support team.
But smaller companies, startups, or mission-oriented teams are different. Everyone codes. Everyone debugs. Everyone joins the on-call rotation. And participation in the culture is part of building trust.
I’ve seen senior engineers show up, stay passive during incidents, and skip fun team rituals, all while acting like their heads are down on “real work.” But what their teammates see is someone who isn’t showing up for the team. Over time, this creates distance and that distance becomes career-limiting.
What should managers do?
As engineering managers, we’re often the first to spot the signs: mounting friction in meetings, rants about the new teammates in 1:1s.
The instinct is often to step back and let things settle. But early intervention. done with care, can make all the difference.
Here’s what I’ve found helpful:
- Set expectations explicitly. Don’t assume a senior engineer will automatically grasp what “being hands-on” means at your company. Be clear about expectations — from contributing to the codebase to engaging in the team culture.
- Talk about these anti-patterns openly. Don’t tiptoe around it. It’s often helpful to have a candid conversation during onboarding about common traps that senior engineers fall into when switching jobs. Most appreciate the clarity. I have an explicit principle that I lay out for senior engineers in one of our initial 1:1s after they join — “The responsibility of adapting falls on the senior-most person in the situation”. Whether it’s a meeting, a team, or a new org, seniority isn’t about being the loudest voice in the room. It’s about being the one who reads the room, adapts their style, and leads by example.
- Facilitate trust-building, not just onboarding. Intros and documents are not enough. Pair the new engineers up on projects with existing team members. Encourage collaboration. Help them earn credibility through shared work.
- Coach them on business and cultural context. Especially when engineers come from different industries or company stages, help them understand what’s different here. Business models shape engineering tradeoffs. Show them that lens.
- Identify a “first win”. One of the best tools you have as a manager is shaping a 30-60-90 day plan that includes an early, achievable win. This gives the new hire momentum, helps them build trust quickly, and boosts their own sense of belonging.
- Mediate early when there’s friction. If you’re hearing mismatched perspectives in your 1:1s, don’t ignore them. Get both sides talking — directly to each other. Translate intentions. Often, both parties are acting in good faith but speaking past each other.
It’s interesting to see that none of these missteps come from a place of bad intent. In fact, they usually come from a desire to help. But the habits and instincts that served someone well in their previous role don’t always carry over.
The most successful senior engineers I’ve worked with are the ones who treat a new job not as a continuation of their last one, but as a clean slate. They join a new team with an eagerness to learn and contribute, rather than question and judge.
No matter how much experience you bring to the table, a new role is a reputation reset and how you handle that reset makes all the difference.