
Lovro Colic developed and enhanced billing, tax, and payment systems for the getlago/lago-api repository, focusing on robust API and GraphQL features. He engineered multi-payment-method support, advanced wallet and credit note logic, and scalable batch processing for billing operations. Using Ruby on Rails, Go, and SQL, Lovro implemented asynchronous tax processing, background jobs, and precise billing period controls, addressing edge cases in proration, tax compliance, and integration reliability. His work included database migrations, schema evolution, and OpenAPI documentation, resulting in resilient, maintainable backend services that improved billing accuracy, payment flexibility, and developer experience across complex subscription and invoicing workflows.

October 2025 focused on expanding payment flexibility and correcting billing edge cases in Lago API. Delivered multi-payment-methods per customer across API and GraphQL, including a new PaymentMethod model/table, GraphQL resolvers/types/permissions for listing and managing methods, REST endpoints and serializers, a checkout URL generation flow, and mapping to subscriptions, recurring rules, and wallets to support per-entity payments. Implemented robust access controls and surface coverage across GraphQL and REST. Fixed progressive billing credits accuracy by adding a guard against applying credits beyond the original invoice amount and adjusting the calculation logic, with tests validating behavior when credits exceed an invoice. Business impact includes improved customer payment experience, reduced billing errors, and strengthened subscription economics. Technologies demonstrated include GraphQL, REST API design, database migrations, test coverage, and security/permissions patterns.
October 2025 focused on expanding payment flexibility and correcting billing edge cases in Lago API. Delivered multi-payment-methods per customer across API and GraphQL, including a new PaymentMethod model/table, GraphQL resolvers/types/permissions for listing and managing methods, REST endpoints and serializers, a checkout URL generation flow, and mapping to subscriptions, recurring rules, and wallets to support per-entity payments. Implemented robust access controls and surface coverage across GraphQL and REST. Fixed progressive billing credits accuracy by adding a guard against applying credits beyond the original invoice amount and adjusting the calculation logic, with tests validating behavior when credits exceed an invoice. Business impact includes improved customer payment experience, reduced billing errors, and strengthened subscription economics. Technologies demonstrated include GraphQL, REST API design, database migrations, test coverage, and security/permissions patterns.
September 2025 monthly summary focusing on key accomplishments across lago-api and lago-go-client. Highlights include feature deliverables for tax name cleanup, prorated billing accuracy, PDF breakdown support, invoice finalization post-void, NetSuite edge case fixes, and one-off invoice billing interval support in the Go client. These changes improved UI clarity, billing correctness, reporting reliability, post-regeneration automation, and cross-system integration.
September 2025 monthly summary focusing on key accomplishments across lago-api and lago-go-client. Highlights include feature deliverables for tax name cleanup, prorated billing accuracy, PDF breakdown support, invoice finalization post-void, NetSuite edge case fixes, and one-off invoice billing interval support in the Go client. These changes improved UI clarity, billing correctness, reporting reliability, post-regeneration automation, and cross-system integration.
August 2025 performance: Delivered key billing, webhook, and API enhancements across lago-api, lago-openapi, and lago-go-client. Strengthened revenue analytics with per-invoice billing periods, improved dunning workflows via finished-campaign webhook, and introduced granular controls for billable metrics. Fixed a critical early-billing attribution issue for advance charges. Documented API changes to enable downstream automation and predictable behavior. Demonstrated API design, data modeling, and cross-repo collaboration to deliver tangible business value.
August 2025 performance: Delivered key billing, webhook, and API enhancements across lago-api, lago-openapi, and lago-go-client. Strengthened revenue analytics with per-invoice billing periods, improved dunning workflows via finished-campaign webhook, and introduced granular controls for billable metrics. Fixed a critical early-billing attribution issue for advance charges. Documented API changes to enable downstream automation and predictable behavior. Demonstrated API design, data modeling, and cross-repo collaboration to deliver tangible business value.
July 2025 performance highlights: Delivered critical features for billing governance, stabilized cascade operations, and expanded wallet controls, alongside API schema enhancements to reduce integration friction. These changes improve revenue accuracy, operational reliability, and developer productivity across lago-api and lago-openapi.
July 2025 performance highlights: Delivered critical features for billing governance, stabilized cascade operations, and expanded wallet controls, alongside API schema enhancements to reduce integration friction. These changes improve revenue accuracy, operational reliability, and developer productivity across lago-api and lago-openapi.
June 2025 highlights across lago-openapi, lago-api, and lago-go-client focused on API quality, billing accuracy, and system resilience. Delivered cross-repo enhancements that improve API consumer experience, enable complex billing scenarios, and increase platform reliability and security. Key outcomes include improved credit notes handling in OpenAPI, granular wallet restrictions by fee types with precise per-fee credits, scalable batch processing for child charges, robust retry mechanisms under API throttling, and up-to-date dependencies for stability and security.
June 2025 highlights across lago-openapi, lago-api, and lago-go-client focused on API quality, billing accuracy, and system resilience. Delivered cross-repo enhancements that improve API consumer experience, enable complex billing scenarios, and increase platform reliability and security. Key outcomes include improved credit notes handling in OpenAPI, granular wallet restrictions by fee types with precise per-fee credits, scalable batch processing for child charges, robust retry mechanisms under API throttling, and up-to-date dependencies for stability and security.
Concise monthly summary for May 2025 focusing on business value and technical achievements across the lago-api repo. Highlights include end-to-end Avalara tax integration enhancements, GraphQL integration filtering improvements, and wallet fee limitation support, with targeted fixes to improve reliability and traceability.
Concise monthly summary for May 2025 focusing on business value and technical achievements across the lago-api repo. Highlights include end-to-end Avalara tax integration enhancements, GraphQL integration filtering improvements, and wallet fee limitation support, with targeted fixes to improve reliability and traceability.
April 2025 monthly summary for getlago/lago-api focusing on Avalara integration and tax-related improvements. Delivered end-to-end Avalara integration platform with GraphQL support, connection management, customer and company code handling, mapping, settings updates, and robust error handling. Fixed tax calculation correctness for in-advance invoices and refactored tax mutation namespace to a generic, provider-agnostic approach, improving maintainability and business readiness for tax compliance workflows.
April 2025 monthly summary for getlago/lago-api focusing on Avalara integration and tax-related improvements. Delivered end-to-end Avalara integration platform with GraphQL support, connection management, customer and company code handling, mapping, settings updates, and robust error handling. Fixed tax calculation correctness for in-advance invoices and refactored tax mutation namespace to a generic, provider-agnostic approach, improving maintainability and business readiness for tax compliance workflows.
Concise monthly summary for 2025-03 focusing on delivered features, bug fixes, and impact across lago-api, lago-openapi, and lago-go-client. Highlights include reliability and performance improvements in tax handling, correct refunds association in dunning campaigns, resilient JSON parsing in the HTTP client, richer subscription data for invoice previews, and advanced filtering capabilities in the Go client—together driving higher reliability, faster previews, and richer analytics for business decisions.
Concise monthly summary for 2025-03 focusing on delivered features, bug fixes, and impact across lago-api, lago-openapi, and lago-go-client. Highlights include reliability and performance improvements in tax handling, correct refunds association in dunning campaigns, resilient JSON parsing in the HTTP client, richer subscription data for invoice previews, and advanced filtering capabilities in the Go client—together driving higher reliability, faster previews, and richer analytics for business decisions.
February 2025: Delivery focused on stability, accuracy, and performance of invoice tax calculations in lago-api, plus onboarding improvements via first-invoice preview. Removed tax cache to ensure fresh tax data for invoice previews, updated fee tax lookup to use item_key for better accuracy, and optimized EU tax service calls by skipping unnecessary interactions when customer tax-relevant details haven't changed and existing EU taxes are present. Introduced a new invoice preview flow for the first invoice across new and active subscriptions to improve onboarding and billing planning. These changes reduce tax discrepancies, lower tax-service load, and accelerate invoice previews, delivering measurable business value in billing accuracy and cash-flow planning.
February 2025: Delivery focused on stability, accuracy, and performance of invoice tax calculations in lago-api, plus onboarding improvements via first-invoice preview. Removed tax cache to ensure fresh tax data for invoice previews, updated fee tax lookup to use item_key for better accuracy, and optimized EU tax service calls by skipping unnecessary interactions when customer tax-relevant details haven't changed and existing EU taxes are present. Introduced a new invoice preview flow for the first invoice across new and active subscriptions to improve onboarding and billing planning. These changes reduce tax discrepancies, lower tax-service load, and accelerate invoice previews, delivering measurable business value in billing accuracy and cash-flow planning.
January 2025 performance summary focusing on delivering a robust, business-valued invoicing preview capability, along with reliability hardening for taxes and external integrations, and extending preview support to the Lago Go client. The work enables faster billing cycles, improved customer transparency, and a premium feature that reinforces monetization.
January 2025 performance summary focusing on delivering a robust, business-valued invoicing preview capability, along with reliability hardening for taxes and external integrations, and extending preview support to the Lago Go client. The work enables faster billing cycles, improved customer transparency, and a premium feature that reinforces monetization.
Monthly summary for 2024-12 highlighting features delivered, bugs fixed, and overall impact across the Lago APIs and clients. Emphasizes business value, reliability, and technical craftsmanship.
Monthly summary for 2024-12 highlighting features delivered, bugs fixed, and overall impact across the Lago APIs and clients. Emphasizes business value, reliability, and technical craftsmanship.
November 2024 monthly summary for repository getlago/lago-api: Delivered performance, reliability, and config-management improvements across invoicing, plan charges, and tax integrations. Implemented N+1 query fix, cascading plan charge filters, automatic retries for rate-limited invoices, and richer error context for debugging; added targeted tests to validate behavior and ensure stability.
November 2024 monthly summary for repository getlago/lago-api: Delivered performance, reliability, and config-management improvements across invoicing, plan charges, and tax integrations. Implemented N+1 query fix, cascading plan charge filters, automatic retries for rate-limited invoices, and richer error context for debugging; added targeted tests to validate behavior and ensure stability.
October 2024 monthly summary for developer work on lago-api focused on expanding plan management capabilities with cascading updates and overrides.
October 2024 monthly summary for developer work on lago-api focused on expanding plan management capabilities with cascading updates and overrides.
Overview of all repositories you've contributed to across your timeline