How to scale engineering teams, in one sentence: design small teams with clear ownership first, add managers before the pain, then hire one team at a time. Most scaling problems come from doing it in the other order, hiring a wave of engineers into a structure that only worked when everyone fit in one room. The principles below hold for 10 to 25 as much as for 20 to 50; the worked example uses 20 to 50, because that's where the informal team usually breaks.
Key Takeaways
- Keep each team at five to nine people, owning a clear slice of the product or platform.
- Team Topologies puts a practical ceiling on a group of teams at around 50 people, the point where you need another layer.
- Add engineering managers and a platform team before the bottlenecks show, not after.
- Hire in waves of one team at a time and let each wave settle before the next.
The Principles for Scaling Engineering Teams
Team size has a ceiling. Team Topologies, by Matthew Skelton and Manuel Pais, defines a team as "a stable grouping of five to nine people who work toward a shared goal as a unit," and suggests grouping teams into families of no more than fifty people, or up to 150 in high-trust organizations. Those limits build on Robin Dunbar's work on the number of stable relationships people can keep, usually cited as about 150 (Dunbar, 1992). Amazon's version is the two-pizza team: no team should be big enough that two pizzas can't feed it, ideally fewer than 10 people with single-threaded ownership.
Split by ownership, not by layer. A "backend team" and a "frontend team" turn every feature into a handoff. Teams that own a slice end to end, like billing, onboarding, or search, move faster. Conway's law applies: your architecture ends up looking like your org chart, so draw the org chart you want the architecture to match.
Add managers early. A manager with more than eight to ten direct reports struggles to run good one-on-ones. Span of control covers the numbers.
Build a platform team once shared infrastructure hurts. When four or five product teams share CI, deploys, and infrastructure, someone has to own them, or every team builds its own workaround.
Grow in waves. Brooks's law says adding people to a late software project makes it later. Hire 30 engineers in a quarter and every senior engineer becomes a full-time onboarder. Seed each new team with two or three people who already know the codebase, add new hires around them, and give it a quarter to settle.
What Scaling Looks Like by Stage
| Stage | Team shape | Leadership |
|---|---|---|
| 5-20 engineers | 1-3 teams | Founder or head of engineering, tech leads |
| ~20 engineers | 3 teams of 6-7 | 1 VP or head of engineering, tech leads per team |
| ~35 engineers | 5 teams, one of them platform | 2-3 engineering managers |
| ~50 engineers | 6-7 teams, 2 groups | Managers per team, a director or group lead per group |
For the earlier stage, how to scale an engineering team from 5 to 20 goes into the details. Past 20, three things break at once: communication overhead grows faster than headcount, ownership blurs, and the founders or first engineers who held all the context become the bottleneck for every decision.
Where Staff Augmentation Fits in Scaling
Permanent hiring for a whole new team takes months. Staff augmentation works as the flexible layer: staff a new team quickly while permanent roles fill, or add capacity for a project without committing headcount you may not need in a year. Ruzora sends a vetted shortlist within 72 hours, the engineer typically starts two to three weeks after you pick, and you can convert engineers who become core to full-time employees for a fee that steps down with tenure.
A Concrete Version: Scaling From 20 to 50
A Series B SaaS company has 22 engineers in three loose teams and a plan to reach 50 in 18 months.
Quarter one: the VP of Engineering draws the target org of six product teams and one platform team. She promotes two tech leads to engineering managers and hires one external manager. No big hiring push yet. Headcount: 23.
Quarter two: she forms the platform team from three existing engineers who already did most of the DevOps work, plus two senior augmented engineers. Headcount: 25.
Quarters three to five: she adds one product team per quarter, each seeded with two engineers who move from existing teams, plus five new people, a mix of permanent hires and augmented engineers. Headcount grows to 40.
Quarter six: she converts three augmented engineers who became core to their teams into full-time employees, and fills the last 10 roles across the newest teams. Headcount: 50, in seven teams of five to nine, each with a clear owner.
Deploy frequency drops a little in quarter two, then climbs past where it started. The dip is real but small, and likely far smaller than what 28 hires crammed into six months would have caused.
The Honest Counterpoint
Not every company should scale its engineering team. More engineers means more coordination, more management, and higher burn. Before you plan the org, ask whether better tooling, fewer projects, or a sharper roadmap would get you most of the output. AI coding tools have changed how much a small team can ship; how AI is changing engineering team size looks at that.
Frameworks also don't replace judgment. Team Topologies' numbers are guidelines. A team of 10 senior engineers that works well together doesn't need splitting because a book says nine.
Frequently Asked Questions
How do you scale engineering teams without losing speed?
Keep teams small with clear ownership, add managers before any lead has more than about eight reports, and hire one team at a time. Expect a small dip in output while each new team settles.
When should an engineering team add managers?
Usually once any lead has more than about eight direct reports, or once you have more than two or three teams. Between 20 and 50 engineers, expect one manager per team.
How fast can you scale an engineering team from 20 to 50?
Twelve to 18 months is realistic if you hire one team at a time. Faster is possible, but output usually drops while senior engineers spend their time onboarding.
The Bottom Line
Design the teams, add managers, then hire in waves. When a new team needs senior engineers faster than permanent hiring can deliver, request a shortlist or see available engineers, and read how to onboard a staff augmentation team before they start.
Roberto Espinoza is CEO of Ruzora, which helps US startups hire pre-vetted senior LATAM engineers, with a vetted shortlist in 72 hours. See available engineers.
