Using Dynamic Architectures

Dynamic Architectures Meta-Skill

When to Use This Skill

Invoke this meta-skill when you encounter:

• Growing Networks: Adding capacity during training (new layers, neurons, modules)
• Pruning Networks: Removing capacity that isn't contributing
• Continual Learning: Training on new tasks without forgetting old ones
• Gradient Isolation: Training new modules without destabilizing existing weights
• Modular Composition: Building networks from graftable, composable components
• Lifecycle Management: State machines controlling when to grow, train, integrate, prune
• Progressive Training: Staged capability expansion with warmup and cooldown

This is the entry point for dynamic/morphogenetic neural network patterns. It routes to 7 specialized reference sheets.

How to Access Reference Sheets

IMPORTANT: All reference sheets are located in the SAME DIRECTORY as this SKILL.md file.

When this skill is loaded from: skills/using-dynamic-architectures/SKILL.md

Reference sheets like continual-learning-foundations.md are at: skills/using-dynamic-architectures/continual-learning-foundations.md

NOT at: skills/continual-learning-foundations.md (WRONG PATH)

Core Principle

Dynamic architectures grow capability, not just tune weights.

Static networks are a guess about capacity. Dynamic networks let training signal drive structure. The challenge is growing without forgetting, integrating without destabilizing, and knowing when to act.

Key tensions:

• Stability vs. Plasticity: Preserve existing knowledge while adding new capacity
• Isolation vs. Integration: Train new modules separately, then merge carefully
• Exploration vs. Exploitation: When to add capacity vs. when to stabilize

The 7 Dynamic Architecture Skills

1. continual-learning-foundations - EWC, PackNet, rehearsal strategies, catastrophic forgetting theory
2. gradient-isolation-techniques - Freezing, gradient masking, stop_grad patterns, alpha blending
3. peft-adapter-techniques - LoRA, QLoRA, DoRA, adapter placement, merging strategies
4. dynamic-architecture-patterns - Grow/prune patterns, slot-based expansion, capacity scheduling
5. modular-neural-composition - MoE, gating, grafting semantics, interface contracts
6. ml-lifecycle-orchestration - State machines, quality gates, transition triggers, controllers
7. progressive-training-strategies - Staged expansion, warmup/cooldown, knowledge transfer

Routing Decision Framework

Step 1: Identify the Core Problem

Diagnostic Questions:

• "Are you trying to prevent forgetting when training on new data/tasks?"
• "Are you trying to add new capacity to an existing trained network?"
• "Are you designing how multiple modules combine?"
• "Are you deciding WHEN to grow, prune, or integrate?"

Quick Routing:

Step 2: Catastrophic Forgetting (Continual Learning)

Symptoms:

• Performance on old tasks drops when training on new tasks
• Model "forgets" previous capabilities
• Fine-tuning overwrites learned features

Route to: continual-learning-foundations.md

Covers:

• Why SGD causes forgetting (loss landscape geometry)
• EWC, SI, MAS (regularization approaches)
• Progressive Neural Networks, PackNet (architectural approaches)
• Experience replay, generative replay (rehearsal approaches)
• Measuring forgetting (backward/forward transfer)

When to Use:

• Training sequentially on multiple tasks
• Fine-tuning without forgetting base capabilities
• Designing systems that accumulate knowledge over time

Step 3: Gradient Isolation

Symptoms:

• New module training affects host network stability
• Want to train on host errors without backprop flowing to host
• Need gradual integration of new capacity

Route to: gradient-isolation-techniques.md

Covers:

• Freezing strategies (full, partial, scheduled)
• detach() vs no_grad() semantics
• Dual-path training (residual learning on errors)
• Alpha blending for gradual integration
• Hook-based gradient surgery

When to Use:

• Training "seed" modules that learn from host errors
• Preventing catastrophic interference during growth
• Implementing safe module grafting

Step 4: PEFT Adapters (LoRA, QLoRA)

Symptoms:

• Want to fine-tune large pretrained models efficiently
• Memory constraints prevent full fine-tuning
• Need task-specific adaptation without modifying base weights

Route to: peft-adapter-techniques.md

Covers:

• LoRA (low-rank adaptation) fundamentals
• QLoRA (quantized base + LoRA adapters)
• DoRA (weight-decomposed adaptation)
• Post-LoRA PEFT variants (surveyed through ~2024): LoRA+, VeRA, PiSSA, LoftQ, rsLoRA, LongLoRA — see the knowledge-calibration note in the sheet before treating the list as current
• Adapter placement and rank-selection strategies
• Merging adapters into base model
• Multiple adapter management (multi-tenant serving of adapter pools is out of scope — named as a gap, with primary sources)

When to Use:

• Fine-tuning LLMs on limited compute
• Creating task-specific model variants
• Memory-efficient adaptation of large models

Step 5: Dynamic Architecture Patterns

Symptoms:

• Need to add capacity during training (not just before)
• Want to prune underperforming components
• Deciding when/where to grow the network

Route to: dynamic-architecture-patterns.md

Covers:

• Growth patterns (slot-based, layer widening, depth extension)
• Pruning patterns (magnitude, gradient-based, lottery ticket)
• Trigger conditions (loss plateau, contribution metrics, budgets)
• Capacity scheduling (grow-as-needed vs overparameterize-then-prune)

When to Use:

• Building networks that expand during training
• Implementing neural architecture search lite
• Managing parameter budgets with dynamic allocation

Step 6: Modular Composition

Symptoms:

• Combining outputs from multiple modules
• Designing gating/routing mechanisms
• Need graftable, replaceable components

Route to: modular-neural-composition.md

Covers:

• Combination mechanisms (additive, multiplicative, selective)
• Mixture of Experts — Shazeer baseline through Switch / Mixtral / DeepSeek-MoE, Expert Choice routing, auxiliary-loss-free balancing, sparse upcycling
• Adapter merging & task arithmetic — TIES, DARE / DARE-TIES, SLERP, model souping, MergeKit, LoraHub
• Grafting semantics (input/output attachment points)
• Interface contracts (shape matching, normalization boundaries)
• Multi-module coordination (independent, competitive, cooperative)

When to Use:

• Building modular architectures with interchangeable parts
• Implementing MoE or gated architectures
• Designing residual streams as module communication

Step 7: Lifecycle Orchestration

Symptoms:

• Need to decide WHEN to grow, train, integrate, prune
• Building state machines for module lifecycle
• Want quality gates before integration decisions

Route to: ml-lifecycle-orchestration.md

Covers:

• State machine fundamentals (states, transitions, terminals)
• Gate design patterns (structural, performance, stability, contribution)
• Transition triggers (metric-based, time-based, budget-based)
• Rollback and recovery (cooldown, hysteresis)
• Controller patterns (heuristic, learned/RL, hybrid)

When to Use:

• Designing grow/train/integrate/prune workflows
• Implementing quality gates for safe integration
• Building RL-controlled architecture decisions

Step 8: Progressive Training

Symptoms:

• New modules cause instability when integrated
• Need warmup/cooldown for safe capacity addition
• Planning multi-stage training schedules

Route to: progressive-training-strategies.md

Covers:

• Staged capacity expansion strategies
• Warmup patterns (zero-init, LR warmup, alpha ramp)
• Cooldown and stabilization (settling periods, consolidation)
• Multi-stage schedules (sequential, overlapping, budget-aware)
• Knowledge transfer between stages (inheritance, distillation)

When to Use:

• Ramping new modules safely into production
• Designing curriculum over architecture (not just data)
• Preventing stage transition shock

Common Multi-Skill Scenarios

Scenario: Building a Morphogenetic System

Need: Network that grows seeds, trains them in isolation, and grafts successful ones

Routing sequence:

1. dynamic-architecture-patterns - Slot-based expansion, where seeds attach
2. gradient-isolation-techniques - Train seeds on host errors without destabilizing host
3. modular-neural-composition - How seed outputs blend into host stream
4. ml-lifecycle-orchestration - State machine for seed lifecycle
5. progressive-training-strategies - Warmup/cooldown for grafting

Scenario: Continual Learning Without Forgetting

Need: Train on sequence of tasks without catastrophic forgetting

Routing sequence:

1. continual-learning-foundations - Understand forgetting, choose approach
2. gradient-isolation-techniques - If using architectural approach (columns, modules)
3. progressive-training-strategies - Staged training across tasks

Scenario: Neural Architecture Search (Lite)

Need: Grow/prune network based on training signal

Routing sequence:

1. dynamic-architecture-patterns - Growth/pruning triggers and patterns
2. ml-lifecycle-orchestration - Automation via heuristics or RL
3. progressive-training-strategies - Stabilization between changes

Scenario: RL-Controlled Architecture

Need: RL agent deciding when to grow, prune, integrate

Routing sequence:

1. yzmir-morphogenetic-rl (companion pack) - Controller action/observation/reward design, governor and safety gates, rollback-as-RL-signal shaping. This is the canonical home for the RL-controller-decides-mutation loop.
2. dynamic-architecture-patterns - What actions the RL agent can take (this pack)
3. gradient-isolation-techniques - Safe exploration during training (this pack)

Boundary: yzmir-morphogenetic-rl covers WHEN/HOW the controller decides to grow. This pack covers HOW the growable network trains once a decision is made.

Rationalization Resistance Table

Red Flags Checklist

Watch for these signs of incorrect approach:

• No Isolation: Training new modules without gradient isolation from host
• No Warmup: Integrating new capacity at full amplitude immediately
• No Gates: Integrating based only on time, not performance metrics
• Naive Combination: Summing module outputs without gating or blending
• Ignoring Forgetting: Adding new tasks without measuring old task performance
• No Rollback: No plan for what happens if integration fails

Relationship to Other Packs

Intersection with deep-rl + morphogenetic-rl: If using RL to control architecture decisions (when to grow/prune), the canonical home for that work is yzmir-morphogenetic-rl (controller, governor, rollback shaping). Compose with yzmir-deep-rl's policy gradient / actor-critic methods for the algorithm side, and this pack's lifecycle orchestration for the network-training side.

Counterfactual evaluation: Before committing to a live mutation (grow/prune), use deep-rl's counterfactual-reasoning.md to simulate the change and evaluate outcomes without risk. This is critical for production morphogenetic systems.

Diagnostic Question Templates

Use these to route users:

Problem Classification

• "Are you training on multiple tasks sequentially, or growing a single-task network?"
• "Do you have an existing trained model you want to extend, or starting fresh?"
• "Is the issue forgetting (old performance drops) or instability (training explodes)?"

Architectural Questions

• "Where do new modules attach to the existing network?"
• "How should new module outputs combine with existing outputs?"
• "What triggers growth? Loss plateau, manual, or learned?"

Lifecycle Questions

• "What states can a module be in? (training, integrating, permanent, removed)"
• "What conditions must be met before integration?"
• "What happens if a module fails to improve performance?"

Summary: Routing Decision Tree

START: Dynamic architecture problem

├─ Forgetting old tasks?
│  └─ → continual-learning-foundations

├─ New module destabilizes existing?
│  └─ → gradient-isolation-techniques

├─ Fine-tuning LLM efficiently?
│  └─ → peft-adapter-techniques

├─ When/where to add capacity?
│  └─ → dynamic-architecture-patterns

├─ How modules combine?
│  └─ → modular-neural-composition

├─ Managing grow/train/integrate cycle?
│  └─ → ml-lifecycle-orchestration

├─ Warmup/cooldown for new capacity?
│  └─ → progressive-training-strategies

└─ Building complete morphogenetic system?
   └─ → Start with dynamic-architecture-patterns
      → Then gradient-isolation-techniques
      → Then ml-lifecycle-orchestration

Reference Sheets

After routing, load the appropriate reference sheet:

1. continual-learning-foundations.md - EWC, PackNet, rehearsal, forgetting theory
2. gradient-isolation-techniques.md - Freezing, detach, alpha blending, hook surgery
3. peft-adapter-techniques.md - LoRA, QLoRA, DoRA, adapter merging
4. dynamic-architecture-patterns.md - Grow/prune patterns, triggers, scheduling
5. modular-neural-composition.md - MoE, gating, grafting, interface contracts
6. ml-lifecycle-orchestration.md - State machines, gates, controllers
7. progressive-training-strategies.md - Staged expansion, warmup/cooldown