Quick start
For a single runner with fewer than 1000 users:| Runner Name | Max Users | Region | AZs | EC2 Subnet | LB Subnet | Capacity |
|---|---|---|---|---|---|---|
| us-east | 1000 | us-east-1 | 2 | /23 (512 IPs) | /28 (16 IPs) | 1019 |
Multi-region example
| Runner Name | Users | Region | AZs | EC2 Subnet | LB Subnet | Capacity |
|---|---|---|---|---|---|---|
| us-east | 500 | us-east-1 | 3 | /22 (1024 IPs) | /28 (16 IPs) | 3068 |
| us-west | 100 | us-west-1 | 2 | /23 (512 IPs) | /28 (16 IPs) | 1019 |
| europe | 300 | eu-west-1 | 2 | /21 (2048 IPs) | /28 (16 IPs) | 4091 |
Planning steps
1. Select regions
Choose AWS regions with optimal latency for your users. Plan subnet sizes for each region upfront.2. Estimate users per region
For each region, estimate maximum users including:- Current users and expected growth
- Peak usage patterns
- Geographic distribution
3. Determine availability zones
- Use 2-3 AZs per region for high availability
- One subnet required per AZ
- More AZs = better fault tolerance but more complexity
4. Plan subnet sizes
EC2 subnets
Host your development environments:| Consideration | Details |
|---|---|
| IP per environment | 1 |
| Management overhead | ~5 IPs |
| Minimum size | /28 (10 environments) |
| Capacity formula | (Subnet IPs × AZs) - Management IPs |
- EC2 subnets can use non-routable CIDR ranges (e.g., CGNAT)
- Plan generously—expanding subnets later is complex
- For public subnets, enable auto-assign public IP
Load balancer subnets
For the Network Load Balancer:- Must be routable from your internal network
/28(16 IPs) is sufficient for most deployments- One subnet per AZ
- Does not affect environment capacity