Independent Software Engineer— Freelance02/2025 – Present
- Designed and shipped Ksefiliusz, a cross-platform Go/Wails desktop client for Poland's national KSeF e-invoicing system, from XML invoice ingestion to bank-ready transfer files.
- Built two native Rust desktop applications on GTK4/libadwaita and Tauri v2, covering real-time audio, PDF text extraction, and streaming LLM integration against local and hosted models.
- Maintain several open-source projects in Go and Rust, including a terminal SQL client with an MCP server exposing database operations to AI assistants.
- Deliver freelance backend and tooling work for multiple clients, while working extensively in C and x86 assembly and deepening computer science, Linux, networking and security fundamentals through hands-on projects and detailed notes.
Backend Developer— Lerta (currently Photon Energy)10/2022 – 02/2025
IoT platform for supervising PV farms, wind turbines, and biogas plants, plus an energy trading system and customer/admin web applications.
- Developed and operated a distributed backend of ~150 microservices across Go, Java, Python, and TypeScript, supporting an IoT and energy-trading platform.
- Designed and optimized time-series data pipelines in TimescaleDB and InfluxDB, processing billions of records.
- Diagnosed and eliminated production bottlenecks in Kafka and RabbitMQ, improving messaging reliability under load.
- Managed Kubernetes deployments with Helm, Docker, and CI/CD pipelines.
- Resolved production incidents across the infrastructure layers as part of on-call support.
- Participated in technical interviews focused on Go, distributed systems, and system design.
Software Engineer— Amartus10/2021 – 10/2022
Backend and full-stack services for provisioning and monitoring F5 network devices.
- Built backend and full-stack services to provision and monitor F5 BIG-IP devices, covering DNS, L4/L7 load balancing, and firewall configuration over their device APIs.
- Worked across the networking stack, diagnosing requests end-to-end through application, HTTP, proxy, TCP/IP, load balancing, DNS, and firewall layers.
- Provisioned and managed Linux VMs on Type 1 and Type 2 hypervisors for device emulation and test environments.
- Collaborated daily with network engineers across the UK, China, and India.
Backend Developer— Dev an Deliver03/2020 – 12/2021
Mobile service-ordering app and interactive educational platform.
- Built REST and GraphQL APIs in NestJS, integrating Salesforce, Stripe, and HubSpot.
- Implemented asynchronous messaging pipelines with RabbitMQ and high availability in mind.
- Managed cloud infrastructure on Azure and DigitalOcean using Docker and Kubernetes.
- Mentored new team members through code reviews and pair programming.
