The career ladder
One climb, beginner → architect. Every rung is a real role with its own skills and an XP gate. Clear a stage's lessons and pass its gate to be promoted to the next.
- STAGE 0
First Light
Curious Beginner● You are hereFoundationProve you can make a computer do something in three minutes. Print, variables, f-strings — the run-it-and-see-it dopamine hit.
print & variablesf-stringsfirst program4 lessons·Gate 180 XP·0/4 done0/180 XP - STAGE 1
Logic & Loops
Apprentice◌ LockedFoundationControl flow, booleans, loops, debugging — the muscle memory of code that branches and repeats. Ends on your first boss build.
control flowbooleansloopsdebugging6 lessons·Gate 390 XP - STAGE 2
Real Tools
Junior Developer◌ Locked£25k–£32kFunctions, scope, and data structures — lists, dicts, tuples, sets, comprehensions. Your first multi-feature project a stranger could use.
functionslists & dictscomprehensions1st project12 lessons·Gate 600 XP - STAGE 3
Touching the World
Mid-level Developer◌ Locked£35k–£50kFiles & JSON, the stdlib, calling an API, secrets & env-vars, error handling, OOP and your first pytest. Code that survives failure and talks to services.
files & JSONAPIsOOPtesting11 lessons·Gate 720 XP - STAGE 4
Working With Data
Data / ML Engineer◌ Locked£45k–£65kYour first specialism. Schema & batch validation, feature engineering, a rule-based classifier, evaluation metrics, a train→predict→evaluate loop — hand-rolled pure Python.
validationfeature engineeringmetricsML pipeline8 lessons·Gate 760 XP - STAGE 5
Engineering Craft
Senior Developer◌ Locked£55k–£75kThe advanced pure-Python patterns that separate mid from senior — generators, decorators, context managers, asyncio basics, plugin registries, state machines.
generatorsdecoratorsasyncstate machines8 lessons·Gate 1000 XP - STAGE 6
Building With AI
AI-Curious Developer◌ LockedAI-track roleLLM-from-code fundamentals — prompting, system prompts & memory, calling an LLM (stubbed), tool-call dispatch, JSON guardrails. Ends on the AI-Assistant core boss.
promptingtool dispatchJSON guardrailsLLM basics8 lessons·Gate 880 XP - STAGE 7
Automating the Boring Work
Integrations / Automation Engineer◌ LockedAI-track roleProduction ops patterns — retry with backoff, idempotency, config-driven dispatch, rate-limiting, dead-letter handling, step pipelines, scheduling. The bridge into AI engineering.
retry/backoffidempotencypipelinesscheduling8 lessons·Gate 880 XP - STAGE 8
AI Engineering
AI Engineer◌ LockedAI-track roleBuild real AI features — few-shot & structured prompting, robust function-calling, RAG with embeddings + vector search, a minimal agent loop, guardrails, and evals.
RAGembeddingsagentsevals9 lessons·Gate 1000 XP - STAGE 9
AI Architecture
AI Architect◌ LockedArchitect roleThe systems view — multi-agent orchestration, vector-DB design, pipeline/DAG design, scaling & batching, cost control & token budgeting, observability, failure-mode design.
orchestrationvector-DB designcost controltracing8 lessons·Gate 1100 XP - STAGE 10
Reading Code
Reviewer◌ LockedSenior skillThe durable human skill — reviewing other people's code. Read a diff and find the bug, spot the missing edge case, judge structure, catch the security issue, give good feedback.
diff reviewedge casessecurity reviewfeedback6 lessons·Gate 820 XP - STAGE 11
Judging AI Code
AI Architect / Lead◌ LockedLead skillThe headline wedge — reviewing and verifying AI-generated code. Spot the confident-but-wrong output, the hallucinated API, the plausible-but-insecure pattern; write the harness that proves it; decide accept/reject/revise.
AI verificationharness designaccept/rejectcapstone7 lessons·Gate 1000 XP