Mark Tkachenko — Software Engineer

Profile

Software Engineer with 9+ years of experience across backend systems and developer infrastructure. Currently builds agent–IDE protocols and SDKs at JetBrains. Previously owned Koog's AI agent execution core, including concurrency, cancellation, failure recovery, and SQL persistence. Earlier experience includes actor-based logistics services and foundational subsystems for JetBrains Rider.

Experience

JetBrains

Amsterdam · Apr 2020 – Present

Senior Software Engineer — AI DevTools Ecosystem

Jul 2026 – Present

Core maintainer of the Agent Client Protocol (ACP) ecosystem, developing agent–IDE interoperability in collaboration with Zed.
Implemented v2 serialization, protocol version negotiation, and client/agent APIs in the Kotlin SDK.
Implemented configurable LLM providers and in-flight prompt steering in the Claude and Codex adapters, preserving compatibility across independently developed clients.

Senior Software Developer — Cloud Platform / Koog

Mar 2025 – Aug 2026

Core developer responsible for Koog's AI agent execution core, evolving the framework from early development through the 1.0 release.
Designed and implemented graph execution semantics, including node transitions, parallel execution, cancellation, and error handling.
Designed and implemented the persistence subsystem end to end: checkpoint representation, execution-state restoration, and tool re-execution behavior during recovery.
Built pluggable storage abstractions and SQL persistence adapters for H2, PostgreSQL, and MySQL.
Shaped public APIs and Kotlin/Java interoperability; contributed to release engineering, cross-product integrations, and reviews of external contributions.

Software Developer / Senior Software Developer — Rider Platform

Apr 2020 – Feb 2025

Developed Rider's project model, foundational infrastructure underlying project and solution workflows across the IDE; also contributed to the shared IntelliJ Platform.
Independently designed and implemented Problems View and its shared diagnostics API, integrating diagnostics from compilers, linters, Unreal Engine, and Qodana.
Independently designed and implemented the Project Dependency Diagram subsystem for visualizing project dependencies.
Maintained and enhanced the NuGet subsystem, including Azure authentication, enterprise SSO flows, and vulnerable-package analysis.
Integrated AI Assistant with Rider services for project-model context retrieval, usage search, and language-aware code insight; led cross-team architecture reviews and mentored interns and new hires.

Earlier experience

Backend Engineer

AtlasDelivery.io · Moscow · Aug 2018 – Apr 2020

Developed backend systems for customer ratings and real-time order tracking in a logistics platform.
Designed and implemented an actor-based Track & Trace backend using Akka.NET, with state stored in MongoDB and failure handling implemented through actors.
Processed geolocation streams from thousands of mobile devices in a system handling tens of thousands of events per second, measured through production observability tools including New Relic.
Built backend services and real-time updates using ASP.NET Core, SignalR, RabbitMQ, Redis, and PostgreSQL.

Software Engineer

CUSTIS · Moscow · Aug 2017 – Aug 2018

Developed backend and integration components for a large-scale retail ERP system, including a Target Stock Calculator built with ASP.NET Web API and ETL pipelines.
Contributed to Reverse Logistics localization for the Chinese market and modernized legacy WPF/WinForms applications through performance improvements, testing, and code reviews.

Technical skills

Languages: Kotlin · Java · C# · TypeScript · Go · SQL
Backend Engineering: concurrency · actor model · state management · checkpoint/restore · API/SDK design
Databases & Messaging: PostgreSQL · MongoDB · Redis · RabbitMQ
Frameworks: ASP.NET Core · Akka.NET · SignalR
Protocols & Observability: REST · JSON-RPC · New Relic

Open source

Koog: Core maintainer; reviewed external contributions, managed API evolution, and published releases through the framework's transition to 1.0.
Agent Client Protocol: Core maintainer across the Kotlin SDK and Claude/Codex adapters; guided contribution reviews, compatibility decisions, and release automation.
BenchmarkDotNet: Implemented statistical detection of benchmark timings indistinguishable from measurement overhead, generic benchmark support, and .NET runtime detection fixes for Docker.
Additional contributions: Akka.NET message-delivery fixes, OpenAPI Generator C# client improvements, and Apache Pulsar .NET build/CI infrastructure. Author of AkkaRoslynAnalyzer for detecting invalid actor-constructor arguments.

Education

M.Sc. Computer Science and Engineering, Honors — MTUCI, 2019
B.Eng. Multichannel Communications Systems — MTUCI, 2017
Doctoral studies, Machine Learning in Medicine — ITMO University, 2019–2022; degree not completed. Research on machine learning applied to heart disease.

Languages

Russian (native) · English (full professional)