Hi there, I'm Yan Kononenko, a Senior Full-Stack Engineer with 9+ years delivering secure, multi-tenant SaaS and 0→1 products using TypeScript/React, Node.js, and Go. I thrive on turning complex problems into scalable software and enjoy mentoring teams to ship robust features on tight timelines. I have deep experience in AI integrations (LLM RAG, embeddings, evals, guardrails) and PostgreSQL data modeling with Prisma and pgvector, plus cloud-native delivery on Vercel/Cloudflare/AWS. I design with privacy-by-design in mind, set up CI/CD, observability, RBAC, audit trails, and scale architectures with background jobs and event-driven workflows.

Yan Kononenko

Hi there, I'm Yan Kononenko, a Senior Full-Stack Engineer with 9+ years delivering secure, multi-tenant SaaS and 0→1 products using TypeScript/React, Node.js, and Go. I thrive on turning complex problems into scalable software and enjoy mentoring teams to ship robust features on tight timelines. I have deep experience in AI integrations (LLM RAG, embeddings, evals, guardrails) and PostgreSQL data modeling with Prisma and pgvector, plus cloud-native delivery on Vercel/Cloudflare/AWS. I design with privacy-by-design in mind, set up CI/CD, observability, RBAC, audit trails, and scale architectures with background jobs and event-driven workflows.

Available to hire

Hi there, I’m Yan Kononenko, a Senior Full-Stack Engineer with 9+ years delivering secure, multi-tenant SaaS and 0→1 products using TypeScript/React, Node.js, and Go. I thrive on turning complex problems into scalable software and enjoy mentoring teams to ship robust features on tight timelines.

I have deep experience in AI integrations (LLM RAG, embeddings, evals, guardrails) and PostgreSQL data modeling with Prisma and pgvector, plus cloud-native delivery on Vercel/Cloudflare/AWS. I design with privacy-by-design in mind, set up CI/CD, observability, RBAC, audit trails, and scale architectures with background jobs and event-driven workflows.

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Experience Level

Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Intermediate
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Work Experience

Senior Full Stack Developer at Infracore
April 1, 2022 - October 31, 2025
Led the build of a multi-tenant SaaS on Next.js (React, TypeScript) with tRPC/REST and PostgreSQL (Prisma, pgvector); shipped core CRM flows in 8 weeks, improving time-to-first-value by 35% for pilot customers. Implemented LLM-powered RAG search using OpenAI/Anthropic, pgvector embeddings, and LangChain/LangGraph; delivering semantic search and entity dedupe/matching that cut recruiter lookup time by 40%. Designed background processing with Inngest/Temporal for idempotent jobs (embedding pipelines, email/SMS sync, webhooks); added retries and DLQs with Redis to reach 99.9% job success. Set up CI/CD with GitHub Actions, per-PR previews on Vercel, feature flags via GrowthBook, and OpenTelemetry traces with Sentry/Datadog; reducing mean time to diagnose by 45%. Built real-time features (activity timelines, presence, notifications) via WebSockets/Server-Sent Events and Redis streams; increasing user engagement by 22%.
Full Stack Developer at Helixstorm
March 1, 2022 - March 1, 2022
Developed React + TypeScript frontends and Node.js/Go APIs with PostgreSQL and Redis caches; improved critical page load time by 28% via query tuning and CDN caching on Cloudflare. Built background jobs (queues, retries, schedules) for enrichment and notifications using BullMQ/Temporal, enabling reliable processing of 10M+ events/month with strict SLAs. Implemented LLM integrations for summarization and recommendations with Vercel AI SDK and streaming UIs, optimizing latency vs. cost through model routing and token budgets. Hardened auth and enterprise SSO with WorkOS/Okta, added fine-grained RBAC, and comprehensive audit trails, supporting multi-tenant compliance requirements. Automated infra with Terraform and Helm across AWS EKS; added GitHub Actions pipelines and preview environments, shortening cycle time from days to hours.
Software Developer at SmartCat
August 1, 2018 - August 1, 2018
Built data services in Node.js/Go over PostgreSQL with careful relational modeling, transactions, and indexing, reducing heavy-report query times by 60%. Delivered real-time ingestion and event-driven features using Kafka and Redis, supporting downstream analytics and CRM timelines. Added observability (Grafana Cloud/Prometheus/Sentry), cutting P1 detection time by 50% and enabling SLO dashboards. Introduced API versioning (REST/GraphQL), typed contracts, and schema migration practices, stabilizing integrations during rapid iteration. Drove privacy-by-design controls (PII field-level encryption, role scoping, redaction), improving audit outcomes and customer trust.
Junior Developer at HOOLOOVOO
February 1, 2016 - February 1, 2016
Contributed to React/TypeScript and .NET/Node.js services, focusing on clean API design, DTO validation, and error handling patterns that improved stability in production. Implemented unit/integration/e2e tests and lint/format gates (ESLint, Biome) that reduced bug escape rates by 25%. Assisted in CI setup on Jenkins → GitHub Actions migration and containerized builds with Docker, improving build reproducibility and speed. Helped add feature flags and A/B tests (Unleash), enabling safe progressive delivery and data-driven rollouts. Participated in threat modeling sessions and backlog grooming, sharpening scope and de-risking releases.

Education

Bachelor's Degree at Megatrend University
August 1, 2011 - May 1, 2015

Qualifications

AWS Certified Solutions Architect – Associate
January 1, 2020 - October 31, 2025
Certified Kubernetes Administrator (CKA)
January 1, 2021 - October 31, 2025
Terraform Associate
January 1, 2019 - October 31, 2025
Datadog Fundamentals
January 1, 2022 - October 31, 2025

Industry Experience

Software & Internet