Vasyl

VASYL OSYPCHUK
Senior Software Engineer · Software Architecture
Reliable systems. Deliberate complexity.
Kyiv, Ukraine · Remote · [відкрити контакти](див. вище в блоці «контактна інформація») · [відкрити контакти](див. вище в блоці «контактна інформація») · [відкрити контакти](див. вище в блоці «контактна інформація») · github.com/
leveldorado

PROFILE
Senior software engineer with 10+ years of experience designing, building, and evolving production systems
across healthcare, SaaS, observability, communications, and cloud infrastructure. I work hands-on across
architecture and implementation, from de ning service boundaries and data ows to deployment, production
behavior, performance, and evolution.
My approach is pragmatic: start with the simplest architecture that satis es real requirements, understand its failure
modes, and introduce distributed components or operational complexity only when scale, reliability, coordination,
or failure isolation justify them.

SELECTED SYSTEMS & DECISIONS
SmithRx · Own critical capabilities
Led the migration of mission-critical functionality from a complex third-party component to internally owned Go
services, covering architecture, decomposition, implementation, rollout, and production stabilization.
Mailtrap · Optimize before adding resources
Identi ed production bottlenecks and increased backend throughput by approximately 15% without increasing
infrastructure resource consumption.
InsightCat · Distribute where scale requires it
Built customer-facing telemetry systems processing hundreds of gigabytes of logs and metrics per day; removed
synchronous authentication from hot request paths using distributed authorization state.
CloudSimple · Design explicitly for failure
Designed a distributed task scheduler for long-running private-cloud operations where retries, partial failures,
idempotency, recoverability, and observability were rst-class constraints.
SlateUp · Split the monolith where separation pays
Decomposed a websocket-heavy monolith where independent deployment and horizontal scaling provided
concrete operational bene ts.

INDEPENDENT ENGINEERING
BaptizedDragon Software · Software Architect & Engineer 2026 – Present
Part-time independent practice designing and building lean software systems for real businesses.
• Start with the simplest architecture that satis es requirements and add distributed components only when
concrete needs justify them.
• Design and build end-to-end products from problem de nition and architecture through implementation and
production delivery.

Vasyl Osypchuk · Senior Software Engineer · Software Architecture
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PROFESSIONAL EXPERIENCE
SmithRx · Senior Software Engineer 11/2023 – 07/2026
Healthcare bene ts platform. Worked on production backend systems and a major effort to replace a critical
external dependency with an internally owned solution.
• Owned a substantial migration area from architectural design and technical decomposition through
implementation, integration, rollout, and production stabilization.
• Developed Go services and synchronization mechanisms across distributed components, with attention to
correctness, partial failures, retries, and safe migration of existing behavior.
• Worked with engineering and product stakeholders to translate requirements and third-party behavior into
maintainable internal service boundaries and APIs.
• Contributed to design decisions, code reviews, production troubleshooting, monitoring, and iterative
improvement after rollout.
Mailtrap · Senior Go Engineer 08/2022 – 11/2023
Email delivery SaaS. Worked on high-throughput production backend services and infrastructure automation.
• Investigated production performance bottlenecks and increased backend throughput by approximately 15%
without adding infrastructure resources.
• Developed and maintained Go services in the production email-delivery path, where throughput, reliability, and
operational visibility were central concerns.
• Contributed to Terraform-based infrastructure automation, production delivery work ows, design discussions,
reviews, and incident/debugging work.
InsightCat · Senior Software Engineer 12/2020 – 08/2022
Observability and telemetry platform. Built data-intensive backend systems and customer-facing APIs for
ingesting, storing, searching, and browsing telemetry and logs.
• Owned a substantial area of the customer-facing backend, covering architecture decisions, API design,
implementation, deployment, monitoring, and production evolution.
• Built Go services and telemetry pipelines processing hundreds of gigabytes of logs and metrics per day.
• Reworked authorization to remove synchronous authentication calls from hot request paths, replacing them with
distributed authorization caches synchronized through Redis Pub/Sub.
• Used ClickHouse, VictoriaMetrics, Redis, and gRPC where the workload justi ed specialized distributed
components, balancing latency, volume, operational cost, failure handling, and maintainability.

Vasyl Osypchuk · Senior Software Engineer · Software Architecture
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PROFESSIONAL EXPERIENCE · CONTINUED
CloudSimple · Software Engineer 08/2017 – 12/2020
Private-cloud platform later acquired by Google. Built backend systems for provisioning and lifecycle management
of cloud infrastructure.
• Designed and implemented backend services coordinating long-running infrastructure operations across
distributed components.
• Designed a distributed task scheduler to keep provisioning and lifecycle operations reliable despite retries,
partial failures, and operations that could run for extended periods.
• Worked on orchestration and state-management problems where idempotency, recoverability, observability, and
safe retries were important design constraints.
SlateUp · Software Engineer 09/2016 – 08/2017
Real-time product with a websocket-heavy backend.
• Helped decompose a monolith into independently deployable services where separation provided concrete
scaling and deployment bene ts.
• Worked on concurrent, connection-oriented backend behavior and service boundaries supporting horizontal
scaling.

EARLIER EXPERIENCE
WalaHub · Go Engineer, Freelance · 06/2016 – 11/2016 Replaced commercial routing APIs with an
OpenStreetMap-based solution, reducing vendor dependency and operating cost.
PaulCamper · Go Software Engineer · 01/2016 – 07/2016 Built Go services for pro les and authentication;
developed SQL analytics in an established CI/CD environment.
Hotels24 · Software Engineer · 08/2015 – 12/2015 Introduced Go into internal development and built analytics
tooling with MongoDB and JavaScript.
Davintoo · Software Engineer · 04/2015 – 08/2015 Developed and maintained a PHP/JavaScript e-learning
application.
1C · Software Engineer · 11/2014 – 04/2015 Developed SQL reporting and adapted business functionality after
transitioning from laboratory work into software engineering.

CORE EXPERTISE
Software Architecture · Distributed Systems · Go · PostgreSQL · Observability
System Design · API & Data Design · Reliability · Performance Engineering · Production Debugging · CI/CD

EDUCATION
Domuni University · Bachelor's Studies in Philosophy · Ongoing
Bogomolets National Medical University (BNMU) · Specialist Degree, Sanitary and Hygienic Faculty · 2012

Vasyl Osypchuk · Senior Software Engineer · Software Architecture
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