Low-Level Design Template
Draw every subnet, address and resource by name, and keep the exact settings, rules and routes one click behind each one.
Free forever on the Personal plan
Low-level designs: an example
Every name and address
Subnets, servers and endpoints labelled exactly as they will be built.
Settings in tables
Sizes, rules and routes in tables behind each resource, ready to build from.
Code beside the design
Templates and scripts in a Raw tab, next to the resource they create.
The basics
What is a low-level design?
A low-level design (LLD) specifies exactly how part of a system is built: the networks and address ranges, every server or service with its name, size and address, security rules, routes, DNS, and backup and monitoring settings. It turns a high-level design into something an engineer can implement and a reviewer can check line by line.
Low-level designs are long and detailed, which is why they drift from what was built. A diagram labelled with the names and addresses, with the full settings behind each resource, keeps the detail readable and makes gaps easy to spot.
In Blueprintr every subnet and resource on the diagram opens a stratum with its settings in tables, and the infrastructure code can sit beside it in a Raw tab.
Why Blueprintr
Low-level designs engineers build from
Names and addresses on the diagram, every setting behind it.
Labelled down to the address
Draw networks, subnets and zones as nested containers and every resource with its name and address, using the Azure, AWS and network icon sets.
VellumExact settings behind each resource
Give each resource a stratum with its size, version, rules and routes in tables, so the diagram stays readable and nothing is left out.
StratumInfrastructure code beside it
Keep Bicep, Terraform or CLI scripts in a Raw tab with line numbers and highlighting, next to the resource they create.
Compare with what was built
On the Team plan, Continuum Cloud draws what is deployed in AWS or Azure from a read-only scan, with IP address and Security groups views to check against the design.
ContinuumLinked to the HLD
Link the LLD to the high-level design it implements, and each resource to the decision behind it, so reviewers can trace every choice.
Approved for build
On team-owned blueprints, require approval before a change is merged into the published LLD, and keep a snapshot of each approved version.
How to
How to write a low-level design in Blueprintr
Create a blueprint
Sign up free and create a blueprint for the part of the HLD you are detailing.
Draw the network
Add the virtual network and its subnets as containers, each labelled with its range.
Place every resource
Add each server, database and endpoint in its subnet, named and addressed as it will be built.
Add the settings
Right-click each resource and add a stratum with its settings, and the code in a Raw tab.
Review and approve
Share the LLD with reviewers and publish the version approved for build.
Start from a template
AWS three-tier web application
An edge, a load-balanced application tier across two zones and managed databases, with strata for the VPC and subnet design, a security-group matrix, alarms and a runbook.
FAQ
Questions about low-level designs
Is this low-level design template free?
Yes. The Vellum editor, the Azure, AWS and network icon sets, strata and Raw tabs are on the free Personal plan. Continuum Cloud and approval workflows are part of the Team plan.
What should a low-level design include?
The address plan, every resource with its name, address, size and version, security rules, routes, DNS, backup and monitoring settings, and the high-level design decision each part implements.
What is the difference between an HLD and an LLD?
The high-level design agrees which parts exist, how they connect and why. The low-level design specifies how each part is built, down to names, addresses, sizes and rules, ready for an engineer to implement.
Can Blueprintr generate an LLD from my cloud?
Not the design itself. On the Team plan, Continuum Cloud draws what is deployed in AWS or Azure, with a stratum per resource, which works well as an as-built record to compare with the design.
Can I keep infrastructure as code with the design?
Yes. A stratum's Raw tab holds Bicep, Terraform, ARM, CLI or any other code with line numbers and syntax highlighting. Blueprintr stores it; it does not run it.
How do I keep the LLD in step with what was built?
Update it as part of each change and publish. On the Team plan, re-sync Continuum Cloud to compare the design with what is deployed; for AWS, Terraform drift is outlined in amber.