Replacing or refactoring a legacy system while it handles live high-throughput traffic is akin to replacing an airplane engine in mid-flight. In high-load environments where even minutes of downtime result in direct revenue loss, full rewrites are often too risky, making incremental refactoring the only viable path. I will provide real-world engineering strategies for safely modernizing legacy monolithic services under active load without breaching SLAs or risking data integrity. I am going to cover practical execution patterns: isolating legacy boundaries, leveraging the Strangler Fig pattern, deploying feature flags, and executing shadow reads and dual-writes for data storage migrations. Special emphasis is placed on observability and SRE guardrails — how to structure telemetry, automated circuit breakers, and canary deployments to catch performance regressions instantly during transition phases. The audience will gain hard-earned insights into balancing architectural evolution, system stability, and continuous delivery.
Technical Lead with extensive hands-on experience across backend development (Java, Go, Python), mobile, web, and DevOps practices. Working at the intersection of architecture, reliability, and team leadership, Aliaksandr specializes in building scalable marketplace platforms and leading complex engineering initiatives through uncertainty. Alongside his engineering leadership roles, he is an active founder developing AI-driven startup products.
