Scaling engineering teams from 10 to 100
The journey from a 10-person engineering team to 100+ is one of the most challenging transitions in technology organizations. What works at 10 breaks at 30, and what works at 30 fails spectacularly at 100. According to DORA research, only 18% of organizations successfully maintain their engineering velocity through hypergrowth phases.
The scaling challenge by numbers
According to research from MIT Sloan, engineering productivity typically drops 30-40% during rapid scaling phases, with recovery taking 12-18 months after growth stabilizes.
Organizational evolution stages
The Startup Phase
Flat structure, everyone does everything, verbal communication, minimal process.
The First Structure
First tech leads emerge, basic team boundaries, some written documentation.
The Scaling Transition
Multiple teams, engineering managers, formal processes, growing pains peak.
The Platform Phase
Platform teams emerge, internal tools, standardization, architectural review.
The Enterprise Phase
VP-level leadership, multiple managers of managers, formal org design.
The Dunbar Danger Zone: Teams between 30-70 engineers face the highest risk of dysfunction. Small enough that old patterns feel possible, large enough that they don't work. This is where intentional organizational design becomes critical.
Team structure evolution
Single Team
10 engineers, 1 tech lead, everyone knows everything
Feature Teams
25 engineers, 3-4 teams, feature ownership, some specialization
Pod Structure
50 engineers, cross-functional pods, product + engineering alignment
Domain Teams
75 engineers, bounded contexts, platform vs product split
Tribes & Squads
100+ engineers, spotify model variants, chapters for disciplines
The hiring challenge
Typical Engineering Hiring Funnel (% remaining)
Building the management layer
Engineering Management Roles by Team Size
| Feature | 10 Engineers | 30 Engineers | 60 Engineers | 100 Engineers |
|---|---|---|---|---|
| Tech Lead | ✓ | ✓ | ✓ | ✓ |
| Engineering Manager | ✗ | ✓ | ✓ | ✓ |
| Sr Engineering Manager | ✗ | ✗ | ✓ | ✓ |
| Director of Engineering | ✗ | ✗ | ✓ | ✓ |
| VP Engineering | ✗ | ✗ | ✗ | ✓ |
| CTO | ✓ | ✓ | ✓ | ✓ |
Promote or Hire?: The best engineering managers are often promoted from within. But rapid scaling requires external hires too. Aim for 60-70% internal promotions to maintain culture, 30-40% external hires for new perspectives.
Process evolution
Minimal Process
Ship when ready, informal code review, verbal standups, Slack everything.
Basic Structure
Sprint planning, PR requirements, deployment pipelines, incident response basics.
Formalized Practices
Architecture review, RFC process, career ladders, formal 1:1s, OKRs.
Governance Layer
Tech radar, investment committees, security reviews, compliance processes.
Scaled Agile
Cross-team coordination, dependency management, portfolio planning.
Communication at scale
Communication Mix at 100+ Engineers
Write Things Down
RFCs, ADRs, runbooks, docs become the source of truth
Default Async
Meetings for decisions only, updates via docs
Clear Ownership
Every system, service, process has clear owners
Structured Sync
Weekly team syncs, monthly all-hands, quarterly planning
Information Radiators
Dashboards, wikis, status pages for self-service
Context over Control
Share why decisions are made, not just what
Technical architecture for scale
Technical Practices Adoption at Scale (%)
The platform team imperative
Platform Investment vs Team Velocity
Platform ROI: Organizations that invest 20-30% of engineering capacity in platform/infrastructure see 40-50% higher productivity across product teams compared to those without dedicated platform investment.
Culture preservation during growth
Document Values
Write down what makes your culture special
Hire for Values
Screen for cultural fit in addition to skills
Onboard Intentionally
Culture bootcamp for all new engineers
Celebrate Examples
Recognize behaviors that exemplify values
Address Violations
Culture issues must have consequences
Evolve Deliberately
Culture should evolve, but intentionally
Common scaling mistakes
Common Scaling Mistakes Frequency (%)
The Hiring Trap: "A players hire A players, B players hire C players." Maintaining hiring bar during hypergrowth is essential. One bad hire at a senior level can set the organization back months.
Metrics for healthy scaling
Key Metrics by Organization Size
| Feature | 10 Engineers | 50 Engineers | 100 Engineers |
|---|---|---|---|
| Deploy Frequency | ✓ | ✓ | ✓ |
| Lead Time | ✓ | ✓ | ✓ |
| MTTR | ✗ | ✓ | ✓ |
| Change Failure Rate | ✗ | ✓ | ✓ |
| Employee NPS | ✗ | ✓ | ✓ |
| Voluntary Turnover | ✗ | ✓ | ✓ |
FAQ
Q: When should we make our first engineering manager hire? A: When you have 10-15 engineers and the technical leader is spending more than 50% of their time on people management. Don't wait until you're overwhelmed.
Q: Should we hire experienced managers or promote from within? A: Ideally both. Promote your best technical leaders who want to manage, and hire experienced managers who can mentor them. The mix provides both culture continuity and new perspectives.
Q: How do we maintain velocity during rapid hiring? A: Accept a temporary productivity dip. Budget 20-30% of senior engineer time for onboarding. Pair new hires with experienced engineers. Strong documentation reduces ramp-up time.
Q: When do we need to split into multiple teams? A: When the current team exceeds 8-10 people, when communication overhead increases significantly, or when you can define clear ownership boundaries. Earlier is usually better than later.
Sources and further reading
- DORA State of DevOps Report
- An Elegant Puzzle by Will Larson
- The Manager's Path by Camille Fournier
- Team Topologies by Skelton & Pais
- Accelerate by Forsgren, Humble & Kim
Scale with Confidence: Growing engineering organizations requires expertise across hiring, organizational design, and technical architecture. Our team has helped companies successfully scale through hypergrowth phases. Contact us to discuss your scaling strategy.
Preparing to scale your engineering organization? Connect with our engineering leadership experts to develop a tailored growth plan.
