Leonid Sopov

Senior Software Engineer | Go, Python, Perl

Currently Seeking New Opportunities

Software Engineer with 20+ years in backend systems across Go, Python, and Perl.

At MY.GAMES, working on secure payment infrastructure in a high-compliance environment (PCI DSS, GDPR, DORA).

At Acronis, drove legacy modernization (Perl → Go), built automation tooling in Python, and contributed to backend infrastructure across multiple services.

Focused on polyglot backend systems, payment infrastructure, and practical engineering tooling.

Permanently based in Serbia — no relocation or work permit sponsorship required.

Senior Backend Engineer

MY.GAMES — Payment Solutions Department Mar 2024 – Now //2 yrs

Working on secure payment infrastructure under PCI DSS, GDPR, DORA, and internal security policy requirements.

  • Maintained and refactored legacy Perl payment services for security, stability, and testability.
  • Integrated new payment acquirers (Payermax, Stripe, Adyen), implementing 3DS authorization flows, IBAN/country code validation, and anti-fraud system hooks.
  • Built unit, E2E, and pytest-based integration tests for payment acquirer flows.
  • Maintained versioned database migrations using Alembic (Python) across multiple service databases.
  • Established Docker security standards across the team: read-only containers, capability dropping, resource limits.
  • Migrated services from Docker Compose to Kubernetes.
  • Built and maintained the team's shared development environment: reverse proxy, uptime monitoring, mock API services, and Docker orchestration.
  • Optimized stage deployment pipeline from ~9 minutes to 14 seconds: replaced git attribute filters with direct text substitution, optimized startup scripts, and added git caching.
  • Implemented Git-based SSH access management with automated provisioning and account expiration.
  • Fixed security vulnerabilities in payment processing code and automated secret rotation across service configuration files.

Senior Go & Python Developer

Acronis — Platform Department Jul 2020 – Jan 2024 //4 yrs

Worked on backend services and tooling with a focus on legacy migration, API development, and automation.

  • Rewrote the Serial Number parsing service from Perl (with C++ XS bindings) into a standalone Go REST API, eliminating the C++ build dependency.
  • Extended the Go Account Server: migrated API endpoints from the Python backend and resolved critical production issues.
  • Migrated AMQP client library from streadway/amqp to amqp091-go, modernizing async messaging across services.
  • Extended and maintained the Reporting Service: replaced DELETE-based retention with DROP PARTITION for performance, added support for new offering items, and resolved critical production incidents.
  • Built a configuration parser converting multi-sheet XLSX files into structured YAML for license chain management, deployed across cloud and on-premise environments.
  • Implemented E2E tests using Gherkin and Python across multiple services.

Lead of Perl Development Team

Acronis – Perl Applications Department Nov 2019 – Jul 2021 //2 yrs

Led the Perl backend team at Acronis (with the company since 2008), managing up to 6 developers, responsible for core internal services and infrastructure tools.

  • Mentored and supported a team of two developers, ensuring professional growth and effective collaboration.
  • Oversaw code quality, implemented unit testing standards, and maintained internal documentation (including POD).
  • Acted as Release Manager, coordinating deployments and system updates.
  • Wrote detailed design documentation and clarified undocumented system internals.
  • Introduced and enforced code review practices and Perl Best Practices.
  • Migrated a 122,000-line Perl codebase and containerized services using Docker.
  • Served as the single point of contact for all cross-team requests and technical queries related to the Perl backend.

Founder & Solo Engineer

Bible Online Project — only.bible · bibleonline.ru · bible.ru Oct 2003 – Now //23 yrs

Solo-built and operated for 20+ years. Platform serving 2M+ unique users and 10M+ page views per year. Full ownership: architecture, development, deployment, monitoring, and incident response.

  • Multi-layer stack: Traefik → Nginx/NJS → Apache mod_perl2 (HTML::Mason) → MariaDB + Sphinx Search + Memcached.
  • Full-text search in Russian, English, and German via Sphinx Search with custom dictionaries and morphology.
  • Go caching reverse proxy for users in restricted regions: hybrid SQLite + filesystem cache, content transformation pipeline, config for 35+ domains.
  • Go microservice for parsing and normalizing Bible references (bble.ru): multi-language input, Unicode normalization, QR code API.
  • Infrastructure: 100+ Docker containers on a dedicated server with VPS, DNS, and proxy redundancy.
  • Developed a public REST API for Bible texts (api.bibleonline.ru), documented and used by external developers.
  • Operates community across VK (68K+ subscribers), Facebook (7.5K+ likes), and other platforms.