05/01/2026 updated
AS
100 % available
Senior Backend & Distributed Systems Engineer (Elixir, Rust, Ruby)
Poland
Only remote
Engineer's degree in Computer Science, Warsaw University of Technology (2015)Protocol BuffersPostgreSQLRubyRust (Programming Language)BackendApache KafkagRPCElixirMicroservices
Distributed Systems & Event-Driven Architecture
Extensive experience designing and operating distributed, high-scale backend systems using Elixir and Ruby. Expertise in event-driven architectures with Kafka, including real-time projections, WAL/Debezium pipelines, and idempotent consumers.
Payments & Financial Systems
Deep knowledge in building correctness-critical payment and revenue features, including online and terminal payments, payouts, wallets, KYC, reporting, tipping, no-show fees, ledger and reconciliation, with integrations such as Adyen and Checkout.com.
Rust Development & Open-Source
Strong proficiency in Rust for tooling, open-source projects, and performance-sensitive components. Projects include a production-grade API microservice, async networking with Tokio, contributions to rust-clippy, and embedded Rust on ESP32.
Data Engineering & ELT Pipelines
Experience building data and reporting systems and ELT pipelines using Fivetran, dbt, and Snowflake.
Kafka & Real-Time Data Processing
Hands-on experience with Kafka pipelines, WAL/Debezium, and high-volume transactional workflows in production environments.
Infrastructure & Observability
Proficiency with Docker, Kubernetes, CI/CD pipelines, and observability tooling including OpenTelemetry, Datadog, and Sentry.
API Design & Protocols
Knowledge of REST, gRPC, Protobuf, GraphQL, and WebSocket for building and integrating backend services.
PostgreSQL & Database Management
Experience with PostgreSQL, including safe database migrations (excellent_migrations tool with 3.5M+ downloads) and static analysis for unsafe migration prevention.
Domain-Driven Design (DDD)
Application of DDD principles to understand complex domains and reduce unnecessary complexity in large-scale systems.
Mobile Development (Android/Java)
Prior experience developing multiple mobile applications for Android using Java, including Bluetooth proximity beacon integrations and product ownership for iOS launch.
Extensive experience designing and operating distributed, high-scale backend systems using Elixir and Ruby. Expertise in event-driven architectures with Kafka, including real-time projections, WAL/Debezium pipelines, and idempotent consumers.
Payments & Financial Systems
Deep knowledge in building correctness-critical payment and revenue features, including online and terminal payments, payouts, wallets, KYC, reporting, tipping, no-show fees, ledger and reconciliation, with integrations such as Adyen and Checkout.com.
Rust Development & Open-Source
Strong proficiency in Rust for tooling, open-source projects, and performance-sensitive components. Projects include a production-grade API microservice, async networking with Tokio, contributions to rust-clippy, and embedded Rust on ESP32.
Data Engineering & ELT Pipelines
Experience building data and reporting systems and ELT pipelines using Fivetran, dbt, and Snowflake.
Kafka & Real-Time Data Processing
Hands-on experience with Kafka pipelines, WAL/Debezium, and high-volume transactional workflows in production environments.
Infrastructure & Observability
Proficiency with Docker, Kubernetes, CI/CD pipelines, and observability tooling including OpenTelemetry, Datadog, and Sentry.
API Design & Protocols
Knowledge of REST, gRPC, Protobuf, GraphQL, and WebSocket for building and integrating backend services.
PostgreSQL & Database Management
Experience with PostgreSQL, including safe database migrations (excellent_migrations tool with 3.5M+ downloads) and static analysis for unsafe migration prevention.
Domain-Driven Design (DDD)
Application of DDD principles to understand complex domains and reduce unnecessary complexity in large-scale systems.
Mobile Development (Android/Java)
Prior experience developing multiple mobile applications for Android using Java, including Bluetooth proximity beacon integrations and product ownership for iOS launch.
Languages
EnglishFluentPolishNative speaker
Project history
Senior backend engineer at a SaaS booking and payments platform (25M+ bookings/month, 120k+ active businesses). Built distributed backend services in a mixed architecture (modular monolith, microservices, legacy Elixir). Designed event-driven systems using Kafka with real-time projections and WAL/Debezium pipelines. Delivered correctness-critical payment features (Adyen, Checkout.com): online and terminal payments, payouts, wallets, KYC, reporting, tipping, no-show fees, ledger and reconciliation. Built data and reporting systems and ELT pipelines (Fivetran, dbt, Snowflake). Led cross-team initiatives as Delivery Owner, including rollout of Adyen payment terminals. Contributed to system reliability, observability, CI/CD, tooling, and devex. Reduced Datadog tracing volume by ~75%. Participated in 24/7 on-call rotations, incident response, and postmortems. Mentored and onboarded new team members.
Worked directly with startup founders as the sole backend developer at an early-stage startup, owning backend delivery end-to-end.
Boosted backend skills working on multiple Ruby on Rails projects at a venture builder. Worked on Indoorway, an indoor location and movement-tracking system for large facilities.