AI system design for backend engineers

Diagrams that think.Systems that ship.

Skeema turns a prompt into a production-quality architecture — then derives the ER schema, sequence flows, and code for every service. One workspace. One source of truth.

  • No credit card
  • Free forever for solo
  • Open source friendly
Sskeema / iot-telemetry● saved~5K usersExport
ActualAI SuggestedTimeline
Launch100›10K10K›100K100K›1M1.0M
Phase: 100K×
Score
C 73
Cost
$80/mo
+$20
Unlocks at this tier
Put a load balancer in front of the gateway
Above ~100K users a single gateway is a fail-stop point. Front it with an LB to scale horizontally.
Adopt this phase
Legend
AI suggested
Code generated
Critical risk
Improvement
BuildAskIoT telemetry platform — device fleet, stream processing, time-series storeGenerate
01The problem

Every diagram tool stops at the diagram.

You draw an architecture. Then you redraw the ER schema from scratch. Then the sequence flow from scratch. Then you write the code with the diagram closed. Nothing stays in sync. Every artifact is an island.

That's not system design. That's documentation theater.

01

Disconnected outputs

Architecture, ER schema, and sequence flows each live in their own file with nothing linking them together.

02

No system intelligence

The tool knows your shapes, not your services. No load simulation, no schema validation, no cost signal.

03

Code drifts immediately

Generated boilerplate never reflects what the diagram actually says — so the diagram rots the day you ship.

02The Skeema Approach

Three things, all connected.

The architecture is the source of truth. Every other view is derived from it — and stays linked.

CLIENT#W001
Web
CLIENT#W002
Mobile
GATEWAY#A101
API
SERVICE#S201
Auth
DATABASE#D301
Postgres
01

Start with the system

Describe your backend in plain English. Skeema generates a production-quality architecture with realistic services, infrastructure, and async patterns.

Auth Service#S201
ERFlowCode
↓
CODE · AUTH.TSgenerated
export async function
login(req, res) {
// derived from flow
}
02

Derive every view

Hover any node → generate an ER diagram for the database. A sequence diagram for the service. Production code for the API. All linked back to their source.

System Architecture14 nodes
ER · PostgreSQL5 entities
Flow · User Login5 actors
API · Auth ServiceTypeScript
03

One living project

Everything lives in a Skeema Project. Edit the architecture, and your derived views know. No more silent drift between diagram and code.

03Live Demo

From prompt to system. In one sentence.

Press any key in the prompt below — Skeema will reveal the production-quality backend it generates, with services, async event flows, and connections.

AI · Architecturepress any key
"Type anything to autocomplete the demo prompt…
claude-haiku-4.5

Awaiting your prompt

Press any key in the box on the left. Skeema will autocomplete the demo prompt, then generate this architecture with all 9 services connected.

9 services·11 connections·3 async event flows·generated in 8s
04The platform

Everything your system needs. In one place.

Not a drawing tool with AI bolted on. Simulation, cost modeling, schema analysis, code generation, and version control — built into every diagram from the first prompt.

Load simulation

Stress-test before you build

Dial from 100 to 100K concurrent users. Skeema computes per-path latencies, grades the architecture A–F, and names the exact bottleneck.

1001K10K100K
P50
64ms
P95
418ms
P99
1.2s
Bottleneck · PostgreSQL — no read replica
B81 / 100
ARCHITECTURE SCORE
Cost estimator

Real cloud bills, pre-deploy

2026 AWS, GCP, and Azure SKUs mapped to every node — with auto-insights.

AWSGCPAzure
$1,284 /mo
Compute · 3× m6i.large$612
RDS Postgres · db.r6g$418
Egress + storage$254
↓ Compute dominates — Reserved Instances save ~31%
Schema health

Nine rules. Zero bad schemas.

Missing keys, absent indexes, orphan entities — caught and graded automatically.

A−
92 / 100 · 9 rules checked
orders — missing PRIMARY KEY
users.email — missing UNIQUE
payments.status — enum candidate
Code generation

Schemas become code instantly

Prisma, PostgreSQL, MySQL, and Mongoose — deterministic output, no AI cost, always in sync with the diagram.

PrismaPostgreSQLMySQLMongoose
model User {
id String @id @default(uuid())
email String @unique
orders Order[]
createdAt DateTime @default(now())
}
Connected views

Derive from any node

Database nodes spawn ER diagrams. Services spawn API routes. Lineage tracked.

DATABASE
PostgreSQL
primary · 5 schemas
ER DiagramSchema CodeAPI Routes
hover any node → derive connected views
Version history

Diff any two versions

Color-coded diffs on canvas. Snapshot, restore, and review like code.

v12 · yesterday→ v14 · now
+Redis Cache — added
~API Gateway — rate limit changed
−Legacy Queue — removed
Flow analysis

Latency on every arrow

Critical paths, sync/async counts, and bottleneck flags on each sequence.

308mstotal · happy path
Client → Gateway
12ms
Gateway → Auth
46ms
Auth → PostgreSQL
215ms
return path
35ms
05Connected diagrams

One system. Every view connected.

Every diagram in Skeema knows where it came from. Your ER schema remembers it was derived from the Postgres node. Your sequence flow knows which services it spans. Edit the architecture, and the connections persist.

ROOT
System Architecture
13 nodes · 22 edges
5 mapped 8 unmapped
ER · PostgreSQL
5 entities
er
Schema Code · PostgreSQL
Prisma · SQL · Mongoose
code
API Routes · Auth Service
TypeScript · 8 routes
api
API Routes · AI Eval
Python · 5 routes
api
Flow · User Login
5 actors · 308ms
flow
Flow · AI Code Evaluation
8 actors · 85ms
flow
Flow · Subscription Billing
6 actors · 380ms
flow

Mint dot indicator

Every node with derived views gets a small mint dot — at a glance, you see what's already mapped.

Hover-strip action menu

Hover any node → a contextual action strip appears with only the actions that apply. No clutter.

Lineage tracking

Delete a source node? Skeema marks the derived board, doesn't break it. Move forward without fear.

06Project Docs

One click. Full project documentation.

Skeema reads your architecture, your ER schemas, and your flows — and writes the docs your team actually needs. Markdown. Versioned. Exportable.

OverviewBoardsDocsSettings
intervee-ai
AI-powered coding interview platform
14
nodes
3
ER schemas
5
flows
Last generated 3m agov4 · 1.2k tokens
Includes
Overview
Architecture
Data Model
Flows
Integrations
Tech Stack
docs.mdgenerated
# intervee-ai

An AI-powered coding interview platform featuring realtime candidate sessions, sandboxed code execution, asynchronous AI evaluation, and Stripe-billed subscriptions.

## Overview

The system handles up to 10,000 concurrent interview sessions, processes code submissions in isolated Firecracker microVMs, and pipelines evaluations through Kafka for asynchronous AI scoring.

## Architecture
  • Web App— Next.js client, server-rendered
  • API Gateway— Fastify · request routing, auth
  • AI Evaluation Service— Python · FastAPI · OpenAI
  • PostgreSQL— primary store · 5 entities
## Data Model

Five entities: users, interviews, submissions, scores, subscriptions. See linked ER diagram for full schema.

## Integrations
  • Stripe— subscriptions, webhooks
  • Kafka— 4 topics · evaluation.requested

Generated in real time · References real component names · Auto-regenerates on demand

07Interactive · system intelligence

Test your architecture before you build it.

Drag the slider to load-test this architecture from 100 to 100k concurrent users. Nodes light up as bottlenecks form — and Skeema tells you the priority fix.

System Architecture5 nodes · 5 edges
client#W001
Web App
Next.js · React
OK600 r/s
gateway#A101
API Gateway
Fastify · Node
OK1.4k r/s
service#S201
Auth Service
TypeScript
OK500 r/s
service#S204
AI Evaluation
Python · FastAPI
OK300 r/s
database#D301
PostgreSQL
primary · 5 entities
WARN1.1k r/s
Load Simulation
● 1,000 concurrent users
Concurrent Users1k
A
System Healthy
Score 88/100 · 0 issues
P50
28ms
P95
78ms
P99
142ms
No bottlenecks detected
System stable at 1,000 users.
5
diagram types, one engine
100K
concurrent users simulated
9
schema rules enforced
4
code dialects generated
A–F
every architecture graded
08Built for teams

For teams that actually ship.

Presence, reviews, comments, and full version history — collaboration that lives on the canvas, not in a separate doc.

AM
RK
JL
KS

Real-time presence

Live collaborator avatars on every board. Built for paired design sessions.

RK
Rajesh · 2m
Should we add Redis for session cache?
approved · ready to merge

Reviews + comments

Request reviews, leave per-node comments, approve or request changes. Notifications throughout.

v8nowamanda
v712m agorajesh
v61h agojordan

Version history + diff

Every change is a snapshot. Diff between any two versions with a visual overlay on the canvas.

09Pricing

Simple. Honest.

Start free. Upgrade when your team grows.

Free

Explore without a card

$0/ forever
  • 3 boards
  • 5 AI generations / month
  • 1 load simulation / month
  • 3 chat messages / month
  • PNG export
  • 5 version history snapshots
  • Community support
Most Popular

Pro

For developers who ship fast

$12/ per month
  • Unlimited boards
  • Unlimited AI generations
  • Unlimited simulations & chat
  • PNG, SVG, PDF, Markdown exports
  • Schema codegen + AI suggestions
  • Diff view + unlimited history
  • Priority email support

Team

Real-time collab — coming soon

Custom/ contact sales
  • Everything in Pro
  • Real-time collaboration
  • Shared workspaces
  • Audit logs
  • SSO / SAML
  • Dedicated support

Free forever tier · No credit card required · Cancel anytime · 14-day money-back guarantee

10FAQ

Questions, answered.

How Skeema models systems, generates real code, and what's included in each plan.

Those tools draw shapes. Skeema models systems. Architecture nodes are real services with technology, async patterns, and load behavior — and they derive ER schemas, sequence flows, and production code that stay linked back to the source.

Need a hand?

Real humans — not bots. We typically reply within a few hours during business days.

support@skeema.cloud
Avg response · 3h 24m

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