From 5 to 50: Scaling Your Engineering Team

The engineering practices that worked at 5 people break at 20 — and break again at 50. Here's how to evolve your team structure as you grow.

Every engineering organization goes through growing pains. What works brilliantly at one size becomes a liability at another. The CTO who built a great 5-person team might struggle at 20; the practices that made a 20-person team hum can strangle a 50-person organization.

This isn't failure — it's physics. As systems grow, they need different structures. The challenge is recognizing when you've outgrown your current approach and knowing what comes next.

Stage 1: The Founding Team (1-5 Engineers)

What It Looks Like

Everyone knows everything. There's no formal structure because you don't need one. Decisions happen in hallway conversations. The whole team might fit at one table. Code reviews are fast because everyone understands the whole codebase.

What Works

• High bandwidth communication: Everyone is in the same conversations
• Shared context: No documentation needed when everyone was there for every decision
• Flexibility: Anyone can work on anything
• Speed: No process overhead, minimal coordination needed

Warning Signs You're Outgrowing It

• New hires take months to become productive
• Knowledge lives in people's heads, not in documentation
• The founder/CTO is a bottleneck for every decision
• Meetings start taking up more time than coding

Stage 2: The Growth Team (6-15 Engineers)

What Changes

You can no longer rely on everyone knowing everything. The codebase is too big for one person to hold in their head. You start needing specialization, and you can't all fit in one meeting anymore.

What to Introduce

Lightweight team structure: You don't need formal teams yet, but you need to clarify who owns what. Maybe it's "these 3 people focus on the backend, these 4 on the frontend."

Basic documentation: Not everything, but the essentials: architecture overview, onboarding guide, key decisions log. Enough that a new hire can get context without interviewing everyone.

Your first engineering manager: Usually around engineer 8-10, someone needs to focus on people management. Often this is a promoted senior engineer who shows aptitude.

Simple processes: Formalize what you're already doing informally. If you've been doing code reviews, write down expectations. If you have a deployment process, document it.

Common Mistakes

• Promoting your best engineer to manager: Management is a different skill. Some great engineers are terrible managers (and vice versa).
• Over-engineering process: You need lightweight structure, not enterprise bureaucracy.
• Ignoring culture: Culture that formed organically with 5 people needs intentional cultivation at 15.

Stage 3: The Scaling Team (16-30 Engineers)

What Changes

This is where many organizations hit their first real crisis. The informal approaches that got you here actively work against you. You need real structure.

What to Introduce

Proper teams: Not just informal groupings, but teams with clear ownership, dedicated managers, and defined scope. Typically 5-8 engineers per team.

Team structures: The two most common models:

• Feature teams: Cross-functional teams that own a feature or product area end-to-end
• Platform/product split: Some teams focus on shared infrastructure, others on user-facing features

Engineering levels: You need clear expectations for different levels (junior, mid, senior, staff) and paths for advancement.

Formal planning: Quarterly or monthly planning cycles. Roadmaps. Commitments. The days of "we'll figure it out" are over.

Hiring process: You're hiring enough that you need a structured, repeatable process. Interview kits, scoring rubrics, calibrated interviewers.

The Manager Layer

At this size, you likely need 3-5 engineering managers. This creates a new challenge: how do managers coordinate? Who do they report to?

Often the CTO is still managing managers directly at this stage. But as you approach 30 engineers, you'll start needing a VP of Engineering or a layer of senior managers.

Common Mistakes

• Teams that are too siloed: Ownership is good, but teams need to collaborate. Build in cross-team communication.
• Managers who don't manage: Some early managers try to stay individual contributors. At this size, management is a full-time job.
• Ignoring senior IC track: Not everyone should become a manager. Create paths for senior individual contributors.

Stage 4: The Scaled Organization (31-50+ Engineers)

What Changes

You're now running a substantial engineering organization. The CTO role shifts from hands-on to strategic. Coordination costs are real. Culture requires intentional work.

What to Introduce

Management layers: You need directors or senior managers between team leads and the CTO. The CTO can't effectively manage 6+ managers directly.

VP of Engineering: If you haven't already, this is typically when you split the CTO role. The VP of Engineering handles operational leadership while the CTO focuses on strategy.

Platform teams: Shared infrastructure, developer experience, security — these need dedicated teams at this scale.

Cross-functional coordination: How do teams work together? You need mechanisms: architecture review, tech leads sync, cross-team planning.

Formal career development: Calibration processes, promotion committees, documented paths. Ad-hoc career conversations don't scale.

Culture programs: Engineering all-hands, guilds or communities of practice, mentorship programs. Culture doesn't maintain itself.

Organizational Patterns

At 50+ engineers, you need to make conscious organizational design choices:

Domain-based groups: Organize around business domains (payments, user growth, core product). Each domain has multiple teams.

The Spotify model: Squads, tribes, chapters, guilds. Controversial but influential — understand it even if you don't adopt it wholesale.

Product and platform: Separate teams focused on user-facing products from teams focused on internal platforms and infrastructure.

Common Mistakes

• Too much process: Adding process feels like progress but can strangle productivity. Add the minimum needed.
• Ignoring communication costs: At this size, a lot of time goes to coordination. Build that into your planning.
• Losing touch with the ground: As a leader, you're increasingly removed from daily work. Create mechanisms to stay connected.
• Cookie-cutter teams: Not all teams have the same needs. Allow for variation in how teams operate.

Principles That Apply at Every Stage

Stay Ahead of Growth

Start building for the next stage before you're drowning. If you have 15 engineers, start thinking about the 25-engineer structure. Hiring a key manager when you desperately need them is too late.

Evolve, Don't Transform

Big-bang reorganizations are traumatic and risky. Prefer gradual evolution: add a team, formalize a process, create a role. Let changes settle before making more.

Clear Ownership

At every size, make ownership explicit. Confusion about who owns what causes dropped balls, duplicate work, and frustrated engineers.

Default to Trust

Process should enable, not constrain. When you add process, ask: "Is this because we don't trust people?" If so, you might have a people problem, not a process problem.

Listen to Your Engineers

The people doing the work often see problems before leadership does. Create channels for feedback and actually act on what you hear.