CV

Valentyn Solomko

Senior Software Engineer / Technical Lead / CTO

Links: LinkedIn · GitHub · Portfolio

Summary

Seasoned Senior Software Engineer / Technical Lead with 20+ years of professional experience designing and delivering enterprise-grade software systems and AI-driven products. Expert in Go (3+), Java (5+), Groovy (6+), Perl (20+), and TypeScript (1+), with a strong focus on cloud-native development, scalable microservices, and data-intensive automation.

Currently serving as CTO, directing technical strategy and AI workflow integration across multi-product SaaS development with a 20+ person engineering team. Designs and implements AI-assisted engineering workflows — from spec-driven development and multi-model review pipelines to autonomous refactoring and context-engineered AI agents — that measurably accelerate delivery and reduce defect rates.

Recently delivered, hands-on, four production AI systems end-to-end: a conversational RAG platform that automates document generation (100% artefact validity, ~$7/user/month), a voice AI agent handling ~20,000 support calls per month at ~80% automation, a substantial solo rebuild of a field-services SaaS platform (991 commits in 3 months, 474 passing tests, zero vulnerabilities), and primary-contributor work on a modular sales-CRM platform with AI-powered reporting and decision billing (1,366 commits, ~123K LOC). Combines deep technical expertise with hands-on leadership — from architecting scalable APIs and microservices to mentoring teams and driving modernization initiatives. Adept at transforming complex legacy platforms into efficient, cloud-native systems through automation, best practices, and strategic design.

Strong cross-functional communicator and problem-solver, passionate about system performance, software quality, and developer productivity.

Core Competencies: Go & Java Specialist · AI/ML Integration · AI-Assisted Development · AI-Powered Pair Programming · AI-Augmented Spec-Driven Development · RAG & LLM Integration · Cloud-Native Systems · Automation Engineering · Backend Optimization · DevOps Integration · Microservices · CTO / Executive Engineering Leadership · Team Leadership · Technical Mentorship

Skills

Backend Development

Languages: Go, Java, Groovy, Perl, TypeScript, PL/pgSQL, Bash
Frameworks:
- Go: Gin, Cobra + Viper, uber-zap, GORM, sqlc + pgx, gRPC, protobuf, Colly, Goquery, chromedp, river, testing + mockery
- Java: Lombok, Spring Boot, Spring Security, Spring Data
- TypeScript / Node: React 19, Deno, Supabase Edge Functions, Vitest, Playwright
- Perl: perlcritic, perltidy
Architectural Patterns: Microservices, Event-Driven Architecture, Domain-Driven Design (DDD), Clean Architecture, SOLID
Concepts: OOP, Concurrency, API Design, Distributed Systems, Automation Pipelines, Idempotency & Two-Phase Transactions

AI, Intelligent Systems & AI-Assisted Development

Core Areas: Neural Networks, Deep Learning, Retrieval-Augmented Generation (RAG), Predictive Analytics, Intelligent Automation
Paradigms / Approaches: AI-Assisted Development; AI-Powered Pair Programming; Generative AI for Specification and Design; AI-Augmented Spec-Driven Development; AI-Driven Development (AIDD); Autonomous Refactoring and Adaptive Coding; AI-Agent-Driven Development; Context Engineering; Self-Healing Systems
Tooling & Platforms: OpenAI API, Anthropic API, OpenRouter, Ollama (local models), Claude Code, Cursor, Aider, Langfuse, Promptfoo
RAG & Vector Search: pgvector (HNSW), local embeddings (bge-m3), schema-validated LLM function-calling, multi-tenant retrieval
Applications: AI-assisted automation, smart data extraction, conversational document generation, voice agents, decision-support systems, multi-model review pipelines
Integrations: Embedding AI workflows into backend pipelines and SaaS platforms; multi-provider LLM failover (Anthropic, OpenAI, Google, Ollama, OpenRouter); LLM cost optimization

Cloud & DevOps Engineering

Cloud Platforms: Google Cloud Platform (GCP), Google Kubernetes Engine (GKE), OpenShift, Hetzner
Containerization & Orchestration: Docker, Docker Compose, Kubernetes
Infrastructure as Code: Terraform, Ansible, Helm
CI/CD: CloudBees CI (Jenkins), CloudBees SDA (ElectricFlow), GitHub Actions, GitLab CI/CD
Artifact Management: JFrog Artifactory, Nexus
Monitoring & Reliability: Prometheus, Grafana, OpenTelemetry, Loki, Tempo, Langfuse (LLM observability), centralized logging (ELK, uber-zap)
Secrets & Security: SOPS + age, Trivy, security hardening
Deployment: GitHub Pages, Railway, Fly.io, Vercel, Supabase, Upstash, Caddy + Let’s Encrypt
Troubleshooting: metrics, alerts, monitoring, profiling

Data & Storage Systems

Relational: PostgreSQL / Supabase, MySQL, SQLite, Interbase / Firebird — SQL optimization, RLS policies, multi-tenant schema design
NoSQL / Key-Value: MongoDB, Redis / Upstash, BerkeleyDB, LevelDB
Focus: Schema design, performance tuning, high availability, caching strategies

System Design & Architecture

Domains: Distributed Systems, High Availability, API Gateways, Event Processing, Fault Tolerance, Load Balancing
Web Infrastructure: Apache, Nginx, Load Balancing, Security Hardening
Operating Systems: Linux (CentOS, Ubuntu), FreeBSD, Windows
Design Competence: UML modeling, architectural documentation, system refactoring, finite state machines
Design Patterns: SOLID, Clean Architecture, Domain-Driven Design

Version Control & Tooling

VCS: Git (GitHub, GitLab, Bitbucket), SVN, CVS
Project Tools: Jira, ClickUp, Confluence, Gradle, Postman, UML, GraphViz, yEd, VSCode, IntelliJ IDEA, Geany
Bot Development: Telegram, Discord, WhatsApp, SMS/Voice (autoresponders, crypto bots, e-commerce)
Web Scraping: Anti-detection, captcha-solving, proxy rotation, distributed processing, information retrieval, intelligent ETL pipelines

Leadership & Collaboration

Roles: CTO, Technical Lead, Architecture Advisor, Mentor
Practices: Agile Scrum, After Action Review, Technical Documentation Standards, AI Workflow Engineering
Project Delivery: Requirements analysis, architecture documentation, cross-functional collaboration
Strengths: Team enablement, code quality governance, stakeholder communication, delivery excellence
Impact: Led 20+ person engineering teams; improved developer efficiency through AI-assisted workflows; delivered multi-product SaaS platforms with measurable reliability gains

Employment History

Freelance Software Engineer & CTO | Self-employed | Remote | Oct 2024 – Present

Technical leadership and hands-on delivery of AI-driven backend systems. Serve as CTO for an AI-driven SaaS product company, directing engineering strategy across multiple products with a 20+ person team, while delivering selected client engagements end-to-end.

Technical Leadership & AI Workflow Integration

Direct engineering strategy across multiple products with a 20+ person team
Design and implement AI-assisted engineering workflows: spec-driven development, multi-model PR review pipelines, context-engineered AI agents, autonomous quality gates
Architect multi-product SaaS platforms: React 19 + TypeScript frontends, Deno / Supabase Edge Functions, multi-provider LLM failover with Langfuse observability

Selected Projects & Outcomes

AI Application Assistant — Conversational RAG / GovTech platform (2026). Sole architect, engineer, and DevOps; 8-week MVP + 2-week calibration.
- Go monolith (9 subsystems, single binary) on Hetzner, Telegram bot front end, deployed via Docker Compose
- Retrieval-augmented generation with pgvector (HNSW) and local Ollama bge-m3 embeddings — keeping applicant data on-premise and retrieval resilient to cloud-LLM outages; OpenRouter (Claude / Gemini) for generation
- LLM function-calling with schema validation extracts structured facts and fills Excel templates while preserving interdependent formula chains (excelize)
- 12-state conversation FSM persisted in PostgreSQL; idempotent LLM calls via a two-phase transaction pattern (no duplicate billing or file generation on retry)
- Spec-first delivery, reviewed through a multi-model AI pipeline (Claude, Gemini, GPT-4o, DeepSeek, Grok) producing dozens of ADRs before implementation
- Outcomes: 100% Excel artefact validity, 22% escalation rate, p95 response 10.6s, ~$7 per user/month, delivered on schedule
AI Voice Agent — Customer support automation (2026). Backend and AI integration; 24-day delivery.
- Voice support pipeline: Binotel telephony webhooks → OpenAI Whisper (STT) → GPT-4o-mini function-calling → CRM actions → ElevenLabs / Azure TTS
- Redis session state across stateless webhooks; per-scenario state machines; a strict structured action set as LLM guardrails; pre-recorded + real-time TTS hybrid to eliminate latency
- Outcomes: handled ~20,000 calls/month at ~80% resolution without an operator; operating cost ~$400–700/month
Gym Operations Platform — Field-services SaaS rebuild (2026). Freelance full-stack engineer / AI integration; 3-month solo takeover.
- Took over a partially-built no-code MVP and substantially rebuilt it into a production system — React 19 + TypeScript frontend, Supabase/Deno backend, 991 commits solo
- Automated escalation triggers (staged no-check-in alerts, repeated photo-rejection detection, overdue-shift flagging) replacing manual shift monitoring
- Multi-provider LLM failover (5 providers) for AI photo validation and report generation — validation keeps working through provider outages instead of blocking the field workflow
- Three-Layer data model (Facts → Computation → Interpretation) enforced via row-level security at the schema level; AI-generated interpretation kept append-only, never overwriting source facts
- Development run through a structured multi-agent AI pipeline (planning → tech-lead → code generation/simplification → independent code review, security review, and test generation) to keep a fast solo rebuild from accumulating undocumented tribal knowledge
- Outcomes: ~42K LOC across 270+ files, 474 passing tests (30% test-to-source ratio), zero npm audit vulnerabilities, delivered in 3 months
Sales CRM Platform — Conversation-first CRM with AI reporting & decision billing (2026). Freelance full-stack engineer / AI integration; 3-month engagement, primary contributor.
- Became the primary contributor on a modular sales-CRM rebuild — 1,366 of 2,888 total commits — spanning a React 19 + TypeScript frontend and a Supabase edge-functions backend across 7 independently-versioned modules
- AI gateway with database-driven system prompts (5-minute TTL cache) and automatic provider fallback (Gemini → OpenRouter on rate-limit/provider errors) — AI-dependent features keep working through a provider outage instead of failing the whole pipeline
- Deterministic, append-only billing ledger for AI-assisted actions — no entry ever mutates a prior one; balance is always reconstructible by replaying the ledger
- 23 production cron jobs moved sync, monitoring, and email processing off the request path, keeping the conversation workspace responsive independent of background-sync volume
- Moved staging and production to trunk-based deployment from the same branch, eliminating a class of bugs caused by environment drift
- Outcomes: ~123K LOC across frontend and edge functions, 201 test files, delivered across 3 months
AI Agent Cost Optimization (2026). Cut AI subagent spend 70–85% with a hybrid architecture — cheap OpenRouter models for analytical tasks, Claude Haiku as orchestrator, premium models reserved for high-blast-radius work — with multi-provider failover and pinned model IDs, holding quality on structured tasks.
Open-source & client tooling. Go-based web scraping framework with anti-detection and distributed processing (DataScrapexter); production Telegram bots (weather intelligence, CRM automation, e-commerce); cross-agent AI orchestration mesh (chorus); email validation and marketing automation CLIs.

Backend Development & Architecture

Design and implement scalable backend systems using Go, Java, Groovy, and Perl
Develop RESTful APIs and microservices for high-performance applications
Create custom CLI tools and enterprise-grade software solutions
Optimize database performance and design efficient data storage solutions

Deployment & Data

Databases: PostgreSQL / Supabase, MySQL, MongoDB, Redis / Upstash
Deployment: GCP, Hetzner, GitHub Pages, Railway, Fly.io, Vercel, Docker, Kubernetes

Senior Plugin Developer | CloudBees Inc. | Remote | 2019 – 2024

Engineered enterprise-grade plugins for the CloudBees DevOps platform, focusing on Analytics, CI/CD, and Release Orchestration
Spearheaded a major system refactoring initiative, creating reusable component packages and a Chrome extension
Architected and implemented core platform components, improving system scalability
Led requirements gathering and analysis through direct customer collaboration
Optimized code performance and implemented automated testing frameworks
Established Agile Scrum practices, improving team delivery efficiency
Conducted technical interviews for engineering candidates
Maintained effective communication with cross-functional teams and stakeholders

Technical Environment: Groovy, Java, Perl, Go · Docker, Kubernetes, Helm, Ansible, Terraform · CloudBees CI (Jenkins), CloudBees SDA (ElectricFlow), GitLab CI · JFrog Artifactory, Nexus · BigIP, OctopusDeploy · Git (GitHub, GitLab, Bitbucket) · Agile Scrum, Feature Management

Plugin Developer | Electric Cloud Inc. (acquired by CloudBees) | Remote | 2018 – 2019

Led plugin development within the Flow Plugin team for an enterprise DevOps automation platform
Engineered and maintained custom plugins extending platform functionality for Fortune 500 clients
Developed comprehensive integration test suites ensuring plugin reliability and performance
Collaborated with distributed teams to maintain continuous integration workflows

Technical Environment: Groovy, Perl · JUnit, integration testing frameworks · Electric Flow (now CloudBees CD) · Docker, Kubernetes · Git · Agile Development

Team Lead, Kyiv Branch | PortaOne LLC | Kyiv, Ukraine | 2013 – 2018

Led the development team building core components for the PortaSwitch BSS and Billing platform
Architected and implemented telecommunications solutions for MNO/MVNO/MVNE providers
Established the “After Action Review” process, improving team performance and project outcomes
Mentored junior developers, accelerating their technical growth and productivity
Facilitated cross-departmental collaboration, streamlining development workflows
Managed integration of VoIP, IoT, and broadband service components
Directed technical initiatives for Communication Service Provider solutions

Technical Environment: Perl, Linux, PortaSwitch · MySQL, PostgreSQL · VoIP, SIP, BSS · High-availability systems · Git · YouTrack, Confluence · Agile, After Action Review

System Architect & Development Head | Internet Invest, Ltd | Kyiv, Ukraine | 2010 – 2013

Architected and led the complete redesign of the enterprise email service platform mail.ua
Managed the backend development department, overseeing 20+ engineers
Established a comprehensive development lifecycle including design, coding, and testing standards
Implemented a service operations framework improving system reliability and maintenance
Led migration to a new architecture, enhancing scalability and performance
Created automated testing and deployment pipelines, reducing delivery time
Developed technical documentation standards and best practices

Technical Environment: Perl, shell scripting · MySQL, PostgreSQL · Linux, Apache · SMTP, POP3, IMAP · Nagios · SVN · Redmine · Waterfall-to-Agile transition

CEO / CTO | TVCom, Ltd (Value-Added Service Provider) | Kyiv, Ukraine | 2008 – 2010

Led company-wide crisis management and digital transformation initiatives
Executed comprehensive IT department restructuring, optimizing operational efficiency
Revitalized mission-critical telecommunications infrastructure: redesigned SMS/MMS gateway systems, modernized VoIP service architecture, and optimized high-traffic WAP/Web platforms
Established robust documentation and support processes
Developed and launched new value-added services, expanding the product portfolio
Managed relationships with mobile carriers and technology partners

Technical Environment: SMS, MMS, VoIP, WAP, web services · SMPP, MM7, SIP, HTTP · Linux, Asterisk, OpenVZ · MySQL, PostgreSQL · Monit · crisis management, IT restructuring

Department Head | Net Style (Value-Added Service Provider) | Kyiv, Ukraine | 2007 – 2008

Established structured software development processes and methodologies
Architected and deployed mobile Value-Added Service Provider (VASP) platforms
Designed and implemented enterprise telephony solutions using Asterisk IP PBX
Created an intelligent IVR services framework for telecommunications
Led the development team delivering mobile value-added services
Streamlined project delivery workflows, improving time-to-market

Technical Environment: Perl, shell scripting · Asterisk IP PBX, SIP · VASP platforms, SMS/MMS · Linux, high availability · MySQL, PostgreSQL · IVR · SDLC, team leadership, resource planning

Senior Developer | Sunny Mobile (Value-Added Service Provider) | Kyiv, Ukraine | 2006 – 2007

Architected and implemented SMS/MMS traffic control systems handling millions of messages daily
Developed control systems integrating multiple protocols (SMPP, SMTP, HTTP, MM4)
Created an interactive SMS service platform for real-time customer engagement
Designed a Device Management System (DMS) for high-load WAP portals
Engineered a remote development environment for distributed team collaboration
Optimized mobile terminal parameter management for improved performance

Technical Environment: Perl, shell scripting · SMPP, SMTP, HTTP, MM4 · SMS/MMS gateways · Linux, high availability · MySQL, PostgreSQL · WAP, HTTP services · high-load systems

Technical Architect & Team Lead | Summit, CJSC | Kyiv, Ukraine | 1997 – 2006

Architected and implemented enterprise-wide distributed systems: a workflow management platform, logistics automation system, and accounting integration framework
Designed and developed an internal document management system serving 500+ users
Led the successful migration of mission-critical workflows from Windows to Linux
Managed the development team delivering enterprise solutions
Maintained 24/7 availability of business-critical systems
Established system monitoring and maintenance protocols
Reduced operational costs through platform standardization

Technical Environment: Delphi, Perl, shell scripting · Linux, Windows · Interbase · distributed systems · custom DMS · workflow automation, logistics · TCP/IP, client-server · CVS · team leadership

Education

Bachelor’s Degree in Physics & Astronomy — National Pedagogical Dragomanov University (NPDU), Kyiv, Ukraine

Languages

English: Professional working proficiency (B2)
Ukrainian: Native proficiency

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