# Learning Paths

~~~admonish info title="Choose a Path"
Each journey covers one topic. The [recommended paths](#recommended-paths) put them in order for different goals.
~~~

## All Journeys at a Glance

| Journey | Exercises | Level |
|---------|-----------|-------|
| [Core: Foundations](coretypes/foundations_journey.md) | 37 | Beginner |
| [Core: Error Handling](coretypes/error_handling_journey.md) | 26 | Intermediate |
| [Core: Advanced Patterns](coretypes/advanced_journey.md) | 26 | Advanced |
| [Effect API](effect/effect_journey.md) | 17 | All Levels |
| [Monad Transformers](transformers/transformers_journey.md) | 29 | Advanced |
| [Concurrency: VTask](concurrency/vtask_journey.md) | 28 | Intermediate |
| [Concurrency: Scope & Resource](concurrency/scope_resource_journey.md) | 20 | Intermediate |
| [Context](context/ch_intro.md) | 59 | Advanced |
| [Effect Handlers](effecthandlers/ch_intro.md) | 19 | Advanced |
| [Optics: Lens & Prism](optics/lens_prism_journey.md) | 30 | Beginner |
| [Optics: Traversals & Practice](optics/traversals_journey.md) | 28 | Intermediate |
| [Optics: Fluent & Free DSL](optics/fluent_free_journey.md) | 22 | Advanced |
| [Optics: Focus DSL](optics/focus_dsl_journey.md) | 90 | Intermediate |
| [Optics: Batching & Coupled Updates](optics/batching_journey.md) | 13 | Advanced |
| [Optics: Boundary Mapping](optics/boundary_mapping_journey.md) | 19 | Intermediate |
| [Expression: ForState](expression/forstate_journey.md) | 13 | Intermediate |
| [Expression: ForPath Parallel](expression/forpath_parallel_journey.md) | 9 | Intermediate |
| [Resilience Patterns](resilience/resilience_journey.md) | 24 | Intermediate |
| [Capstone: One Line, Six Layers Grows Up](capstone/capstone_journey.md) | 7 | Intermediate |

---

## Recommended Paths

~~~admonish tip title="Start Here"
**Path A: Effect-First** is the recommended path for most users. It teaches the primary user-facing API of Higher-Kinded-J and gets us productive quickly.
~~~

### Path A: Effect-First (Recommended)
*The modern approach: start with the user-friendly Effect API.*

| Session | Journey |
|---------|---------|
| 1 | [Core: Foundations](coretypes/foundations_journey.md) |
| 2 | [Effect API: Fundamentals](effect/effect_journey.md#part-1-fundamentals) |
| 3 | [Effect API: Advanced](effect/effect_journey.md#part-2-advanced) |
| 4 | [Optics: Lens & Prism](optics/lens_prism_journey.md) |
| 5 | [Expression: ForState](expression/forstate_journey.md) |

**Total**: 5 sessions

**Best for**: New users who want the recommended learning experience.

---

### Path B: Quickstart
*Get productive with Higher-Kinded-J quickly.*

| Session | Journey |
|---------|---------|
| 1 | [Core: Foundations](coretypes/foundations_journey.md) |
| 2 | [Effect API: Fundamentals](effect/effect_journey.md#part-1-fundamentals) |

**Total**: 2 sessions

**Best for**: Developers who want to use the library immediately without deep theory.

---

### Path C: Practical FP
*Core functional patterns for everyday use.*

| Session | Journey |
|---------|---------|
| 1 | [Core: Foundations](coretypes/foundations_journey.md) |
| 2 | [Core: Error Handling](coretypes/error_handling_journey.md) |
| 3 | [Effect API: Fundamentals](effect/effect_journey.md#part-1-fundamentals) |
| 4 | [Optics: Lens & Prism](optics/lens_prism_journey.md) |
| 5 | [Expression: ForState](expression/forstate_journey.md) |

**Total**: 5 sessions

**Best for**: Developers building production applications who want solid foundations.

---

### Path D: Core Types Deep Dive
*Master the theoretical foundation.*

| Session | Journey |
|---------|---------|
| 1 | [Core: Foundations](coretypes/foundations_journey.md) |
| 2 | [Core: Error Handling](coretypes/error_handling_journey.md) |
| 3 | [Core: Advanced Patterns](coretypes/advanced_journey.md) |

**Total**: 3 sessions

**Best for**: Developers who want to understand the FP theory deeply before applying it. Pair this path with the [Foundations chapter](../hkts/foundations_intro.md) of the book; the journeys exercise the concepts that the book explains.

---

### Path E: Optics Specialist
*Master immutable data manipulation.*

| Session | Journey |
|---------|---------|
| 1 | [Optics: Lens & Prism](optics/lens_prism_journey.md) |
| 2 | [Optics: Traversals & Practice](optics/traversals_journey.md) |
| 3 | [Optics: Fluent & Free DSL](optics/fluent_free_journey.md) |
| 4 | [Optics: Focus DSL](optics/focus_dsl_journey.md) |
| 5 | [Optics: Batching & Coupled Updates](optics/batching_journey.md) |
| 6 | [Optics: Boundary Mapping](optics/boundary_mapping_journey.md) |

**Total**: 6 sessions

**Best for**: Developers working with complex immutable data structures who want to master optics, through to the generated DTO boundary.

---

### Path F: Full Curriculum
*Everything, done properly over multiple sessions.*

| Session | Journey |
|---------|---------|
| 1 | [Core: Foundations](coretypes/foundations_journey.md) |
| 2 | [Core: Error Handling](coretypes/error_handling_journey.md) |
| 3 | [Core: Advanced Patterns](coretypes/advanced_journey.md) |
| 4 | [Effect API: Fundamentals](effect/effect_journey.md#part-1-fundamentals) |
| 5 | [Effect API: Advanced](effect/effect_journey.md#part-2-advanced) |
| 6 | [Monad Transformers](transformers/transformers_journey.md) |
| 7 | [Effect Handlers](effecthandlers/ch_intro.md) |
| 8 | [Expression: ForState](expression/forstate_journey.md) |
| 9 | [Expression: ForPath Parallel](expression/forpath_parallel_journey.md) |
| 10 | [Concurrency: VTask](concurrency/vtask_journey.md) |
| 11 | [Concurrency: Scope & Resource](concurrency/scope_resource_journey.md) |
| 12 | [Context](context/ch_intro.md) |
| 13 | [Resilience Patterns](resilience/resilience_journey.md) |
| 14 | [Optics: Lens & Prism](optics/lens_prism_journey.md) |
| 15 | [Optics: Traversals & Practice](optics/traversals_journey.md) |
| 16 | [Optics: Fluent & Free DSL](optics/fluent_free_journey.md) |
| 17 | [Optics: Focus DSL](optics/focus_dsl_journey.md) |
| 18 | [Optics: Batching & Coupled Updates](optics/batching_journey.md) |
| 19 | [Optics: Boundary Mapping](optics/boundary_mapping_journey.md) |
| 20 | [Capstone: One Line, Six Layers Grows Up](capstone/capstone_journey.md) |

**Total**: 20 sessions

**Best for**: Comprehensive mastery of Higher-Kinded-J.

---

## Combined Journeys

These pairs build on each other and work well taken back to back:

### Error Mastery
Combine [Core: Error Handling](coretypes/error_handling_journey.md) + [Core: Advanced Patterns](coretypes/advanced_journey.md)

Focus: Complete error handling and advanced FP patterns together.

### DSL Power
Combine [Optics: Fluent & Free DSL](optics/fluent_free_journey.md) + [Optics: Focus DSL](optics/focus_dsl_journey.md)

Focus: Master both the Free Monad DSL and the Focus DSL together.

### Effect API Complete
Combine [Effect API: Fundamentals](effect/effect_journey.md#part-1-fundamentals) + [Effect API: Advanced](effect/effect_journey.md#part-2-advanced)

Focus: Master the complete Effect Path API from basics to advanced contexts and annotations.

### Concurrency Complete
Combine [Concurrency: VTask](concurrency/vtask_journey.md) + [Concurrency: Scope & Resource](concurrency/scope_resource_journey.md)

Focus: Master virtual threads, structured concurrency, and resource management together.

---

## Tips for Success

1. **Pause between tutorials, not inside one.** A break between tutorials or journeys helps consolidation.
2. **Don't skip the struggle.** When an exercise is hard, that is where learning happens. Consult solutions only after genuine effort.
3. **Run the tests.** The red-to-green feedback loop is essential. Don't just read the exercises.
4. **Revisit earlier journeys.** After completing later journeys, earlier concepts often make more sense. Circle back.
5. **Apply immediately.** After each journey, try using what we learned in our own code.

---

**Previous:** [Expression: ForState](expression/forstate_journey.md)
**Next:** [Solutions Guide](solutions_guide.md)