AndrésContrerasGuillén

What I build in the open

1. 01The map

   three star systems

   Everything I build in the open orbits one of three stars. We will visit them in order, one world at a time.

   • fireflyframework: one architecture, a planet for each language
   • products: complete applications built on the framework
   • openplatform: open business modules for banking and insurance

   Organizations

   • fireflyframework
   • fireflysoftwaresolutions

   Open source on GitHub / Firefly Software Foundation

   Browse on GitHub on GitHub01 / 17

2. 02Open-source framework

   fireflyframework

   One architecture for your services, in the languages your teams already use. The framework handles the plumbing: composition, persistence, messaging, sagas, resilience, identity and operations. Your native libraries and your domain stay yours.

   • Born inside a core-banking platform
   • Every framework runs multi-step work as compensating sagas
   • Maintained by the Firefly Software Foundation

   Tooling, books and docs

   • flywork cli
   • by example books
   • fireflyframework.org

   Spring Boot / FastAPI / Laravel / Axum / ASP.NET Core

   Visit fireflyframework on GitHub02 / 17

3. 03Python

   pyfly

   The architecture in Python, on FastAPI or Starlette: typed dependency injection, CQRS handlers, sagas, SQLAlchemy repositories and server-rendered HTML.

   • Typed dependency injection and CQRS
   • Compensating sagas
   • The base of weave, forge, flycanon and flyquery

   Python 3.12+ / FastAPI / Starlette / SQLAlchemy

   See pyfly on GitHub03 / 17

4. 04Java

   jafly

   The architecture in Java, modular and reactive on Spring Boot and WebFlux: commands and queries, sagas and try-confirm-cancel, reactive transactions and observability.

   • Sagas and try-confirm-cancel
   • Reactive transactions
   • The engine under firefly openplatform

   In orbit

   • jafly by example

   Java 25 / Spring Boot 4.1 / WebFlux

   See jafly on GitHub04 / 17

5. 05PHP · Laravel

   larafly

   The architecture in PHP, native to Laravel 13: PHP attributes for components, transactions and security rules, with CQRS, a transactional outbox, sagas and event sourcing.

   • Attribute-driven components and security
   • Transactional outbox and sagas
   • Event sourcing

   PHP 8.3+ / Laravel 13

   See larafly on GitHub05 / 17

6. 06Rust

   rsfly

   The architecture in Rust, on Tokio and Axum: dependency injection, typed CQRS dispatch, compensating sagas and SQLx repositories with explicit not-found and optimistic-lock results.

   • Typed CQRS dispatch
   • Compensating sagas
   • Explicit, typed failure results

   Rust 1.88+ / Tokio / Axum / SQLx

   See rsfly on GitHub06 / 17

7. 07.NET

   netfly

   The architecture in .NET, on ASP.NET Core: commands validated and dispatched, attribute-based sagas, structured HTTP errors, all registered through the host’s dependency injection.

   • Validated command dispatch
   • Attribute-based sagas
   • Structured HTTP errors

   C# / .NET 10 / ASP.NET Core

   See netfly on GitHub07 / 17

8. 08Applied AI

   agentic

   A Python library for agents with tools, memory and retrieval, built on Pydantic AI. Applications stay in control: they approve or deny the tools an agent wants to use.

   • Agents with tools, memory and retrieval
   • Human approval for sensitive tools
   • Reasoning patterns, pipelines and tracing

   In orbit

   • agentic studio
   • datascience

   Python / Pydantic AI / OpenTelemetry

   See agentic on GitHub08 / 17

9. 09Products on the framework

   products

   Complete products built on the framework, each one solving a real problem end to end: process automation, a software factory, versioned knowledge and analytics.

   • Built on pyfly and agentic
   • Open source on GitHub
   • Each one helps build the others

   Python / TypeScript

   All repositories on GitHub09 / 17

10. 10Process automation

    weave

    Business processes that run across systems and people, built on pyfly. Runs wait for approvals and events, and record every step they take.

    • Design in Studio, YAML, JSON or Python
    • Workers, human tasks and threaded email
    • APIs, CLI and SDKs to embed it

    Python / pyfly / Studio

    See weave on GitHub10 / 17

11. 11Software factory

    forge

    A software factory that turns a product brief into verified pyfly or larafly software, with coding agents working on bounded tasks and every check on record.

    • From product brief to verified software
    • Coding agents on bounded tasks
    • Executable policies and quality gates

    In orbit

    • forge policies
    • agent bridge

    Python / TypeScript / Agents

    See forge on GitHub11 / 17

12. 12Knowledge

    flycanon

    Versioned knowledge with source provenance, hybrid retrieval and answers that cite where every fact comes from. Built on pyfly and agentic.

    • Versioned, provenance-tracked sources
    • Hybrid retrieval
    • Cited answers

    Python / pyfly / agentic

    See flycanon on GitHub12 / 17

13. 13Analytics

    flyquery

    Ask questions of structured files in plain language, then inspect the SQL behind every answer and keep the history. Built on pyfly and agentic.

    • Natural-language questions
    • Inspectable SQL
    • Query history

    Python / pyfly / agentic

    See flyquery on GitHub13 / 17

14. 14Open business modules

    firefly openplatform

    Open-source business modules for banking and insurance, published as fireflysoftwaresolutions and built on jafly. Layered, so a bank or fintech adopts only what it needs, reads every line, and keeps it. 105 public services across six layers.

    1. core41Systems of record: ledger, accounts, payments, cards, every lending product, customers and KYC/KYB.
    2. domain41Business orchestration over the core, with CQRS command and query buses.
    3. experience13Customer journeys: onboarding, account opening, cards and lending.
    4. app2Gateways for authentication and configuration.
    5. libraries3Payment rails, PSP abstractions and batch infrastructure.
    6. platform5BOM, parent POM, shared configuration and documentation.

    Java / jafly / Spring WebFlux / Kubernetes / Apache 2.0

    Explore fireflysoftwaresolutions on GitHub14 / 17

15. 15Core layer

    core

    The systems of record: ledger and accounts, payments and cards, every lending product, customers, KYC/KYB, documents and contracts. 41 services in this layer alone.

    • Ledger, accounts, payments, cards
    • Origination to collections
    • Customers, KYC/KYB, GL accounting

    Java / R2DBC / Kafka

    See the core services on GitHub15 / 17

16. 16Domain layer

    domain

    Domain services orchestrate the core into business capabilities: lending workflows, product catalog and pricing, KYC/KYB, SCA, notifications and contracts, through CQRS command and query buses. 41 services.

    • Loan origination and servicing workflows
    • Product catalog, pricing and eligibility
    • KYC/KYB, SCA and notifications

    Java / jafly CQRS / Sagas

    See the domain services on GitHub16 / 17

17. 17Experience layer

    experience

    Experience services shape customer journeys on top of the domain: onboarding individuals and businesses, opening accounts, issuing and replacing cards, and applying for loans. 13 services.

    • Individual and business onboarding
    • Account opening and cards
    • Lending journeys

    Java / BFF / OpenAPI

    See the experience services on GitHub17 / 17