Interactive codebase onboarding

Learn any codebase through debugging missions

Paste a GitHub repo URL. Oncode maps the architecture and generates structured challenges that teach you how the system actually works.

Try:
The Problem

Understanding a new codebase
takes months

Modern systems are large, complex, and poorly documented. Getting productive takes far too long.

01
Complex architecture
Modern systems consist of many services, dependencies, and hidden interactions. No single engineer understands all of it.
02
Outdated documentation
Documentation rarely keeps pace with the evolving codebase. What exists is often wrong, incomplete, or written for a system that no longer exists.
03
Tribal knowledge
Critical system knowledge lives with a few senior engineers. When they leave, it leaves with them.
44%of organizations say onboarding takes 2+ months
3–9moindustry estimate to fully ramp up a new hire
The Solution

Interactive missions for understanding codebases

Oncode generates interactive debugging missions directly from a codebase. Engineers learn the system by solving real problems inside it — not by reading stale documentation.

  • Trace real execution paths through the system
  • Explore dependencies between services and components
  • Inspect how services handle real edge cases
  • Diagnose realistic issues in actual code
Mission 03 · Authentication Flow
OBJECTIVE
Trace the request lifecycle from login submission to JWT issuance. Find where token expiry is enforced.
ENTRY POINT
POST /api/auth/login
YOUR TASKS
✓Locate the auth middleware
○Find where the JWT secret is loaded
□Identify the token refresh logic
How it works

From zero to architecture expert

No reading docs. No hand-holding. Structured challenges that reveal how the system is actually built.

01
Paste a GitHub URL
Drop any public repository link. Oncode fetches the structure and begins analysis immediately.
02
AI maps the architecture
We detect entry points, services, data layers and key execution flows — automatically.
03
Complete debug missions
Structured challenges guide you through real system logic. No documentation needed.
oncode · analyzing repository
✓Scanning repository structure
✓Detected TypeScript · Next.js · PostgreSQL
✓Found 14 entry points and 6 service layers
○Generating 7 debugging missions ...
Why It Matters

Faster onboarding, deeper system understanding

Reducing ramp time by even a few weeks saves significant cost — and makes your team more resilient.

01
Engineers ramp up faster
Structured missions guide engineers through real system logic so they contribute meaningfully in days, not months.
02
Senior time freed up
Senior engineers spend less time answering the same onboarding questions and more time building things that matter.
03
Reduced hiring risk
New hires become productive sooner, reducing the long tail of slow onboarding that follows most engineering hires.
04
Genuine system confidence
Engineers gain real understanding of how the system works — not surface-level familiarity that breaks under pressure.
COST OF SLOW ONBOARDINGReducing ramp-up time by 2 weeks saves roughly $5–10k per engineering hire in lost productivity — before accounting for senior engineer time spent hand-holding.
Features

Everything you need to master a codebase

Mission generation
Debugging challenges scaled to the repo — 3 missions for small codebases, up to 12 for large ones.
Architecture mapping
Understand how services, models, and routes connect across the entire codebase.
Code explorer
Navigate files and trace imports inside a lightweight, mission-focused workspace.
Progress tracking
See which missions you have completed and what architectural concepts you have learned.
Who It's For

Built for growing engineering teams

Oncode is designed for engineering teams with 20–200 developers who hire regularly and care about how fast people become productive.

✓Maintains a complex, multi-service codebase
✓Hires new engineers on a regular cadence
✓Cares about developer productivity and velocity
✓Lacks a structured, repeatable onboarding system
TYPICAL BUYERS
VP Engineering
Responsible for developer productivity across the org. Needs measurable improvement in ramp-up time.
CTO
Concerned with team scalability and knowledge resilience as the company grows and hiring increases.
Engineering Manager
Directly manages onboarding. Wants to reduce the burden on senior engineers and get new hires shipping faster.
The Team

About the founders

Technical founders from UCL, building tools they wished had existed.

Afthab Shiraz
UCL · Robotics & AI
Engineering background in robotics and machine learning. Focused on applying AI to developer tooling problems that actually matter in practice — not demos.
Maulik Tripathi
UCL · Computer Science
Software engineering background across full-stack systems. Focused on the product experience, codebase analysis, and making the tool genuinely useful for engineers.

We started Oncode after experiencing firsthand how long it takes to understand a large codebase — and realising that documentation and code review alone were never going to be enough.