Senior Full-Stack Engineer & Tech Lead for 0→1→Scale product platforms.
I’m Oleh Sypiahin, a Senior Full-Stack Engineer and Tech Lead with 9+ years of experience across startup product development, high-load telecom systems, frontend architecture, Kotlin backend services, and Kafka-based event-driven microservices. My strongest value is the full product arc: turning early product ideas into production systems, then scaling and modernizing them through architecture, performance, reliability, and reusable engineering standards.
The differentiator is not only the stack. It is the full product arc.
My strongest value is the full lifecycle of a product platform: building from scratch, launching to production, scaling under real usage, modernizing architecture, and turning production lessons into reusable engineering standards. For U.S. product teams, this means I can contribute hands-on code, improve system architecture, and help the team move faster without sacrificing reliability, maintainability, or product quality.
0→1 builder: helped create, launch, and evolve a low-code/no-code platform from an early product idea into a production system.
Scale engineer: worked on high-load telecom/IoT infrastructure, real-time events, notification pipelines, and usage-based product systems.
Technical leader: defined frontend architecture, reusable project templates, engineering standards, code-review practices, and mentoring/onboarding materials.
Selected case studies
Core 0→1→Scale story
Building a low-code/no-code product platform from 0→1 to scale
The problemThe company needed a flexible platform to accelerate application development for complex telecom and IoT workflows — starting from an early product idea and moving toward a production system that could support real business use cases.
ApproachDesigned and implemented core UI tooling, integration flows, automation features, and scalable frontend architecture. As the product matured, translated repeated engineering patterns into reusable project templates, coding guidelines, review practices, and onboarding materials.
ImpactContributed to the platform during the company’s startup-to-scale phase, including the period connected to a $21.5M raise and merger with floLIVE. The work helped establish a technical foundation for product growth, faster application delivery, and long-term platform modernization.
Platform taken from 0→1 to production and scale.
Latest backend / telecom BSS case
Offer Switching: multi-offer cascade charging for a telecom rating engine
Backend Engineer· 2024–2025
Kotlin
Spring Boot
Kafka
Hazelcast
Telecom BSS
The problemThe real-time rating engine could charge usage from only one offer at a time. When that offer was depleted, otherwise valid sessions could be rejected even if the subscriber still had available balance in other packages — creating a risk of false insufficient-balance outcomes and poor customer experience.
ApproachDesigned and implemented a planner → splitter → executor → consolidator pipeline that cascades a single charge across multiple subscriber offers in priority order. Added per-offer context states (isDepleted / isSettled) to preserve correct charge history across re-cascade and top-up scenarios. Shipped behind a feature flag with a legacy fallback path, and validated START, STOP, rejection, precision, depletion, re-cascade, and live-environment scenarios.
ImpactImproved charging flexibility, reduced the risk of false insufficient-balance rejections, and protected billing integrity through per-offer reconciliation — while preserving a safe fallback to the legacy rating flow.
Zero regression with feature-flag-off legacy fallback
Full per-offer charge reconciliation: no double-counting, no lost charges
Event-driven microservices
Centralized Kafka event bus for real-time product notifications
Backend / platform engineer· 2022–2023
Kafka
Kotlin
Nest.js
Kubernetes
Grafana
Elasticsearch
The problemMultiple product services needed a reliable way to publish and consume user, business, and system events in real time without creating tight service-to-service coupling.
ApproachArchitected an asynchronous Kafka-based event pipeline with producers, consumers, notification flows, and production observability. The system supported in-app, email, and system notifications while making it easier to integrate new product services without changing the core communication layer.
ImpactEnabled decoupled real-time event distribution across product services, reduced integration friction for new features, and improved operational visibility for notification workflows.
Performance / cost optimization
Improving Angular application performance and service-to-client data transfer on AWS
Frontend engineer· 2021–2022
Angular
TypeScript
AWS
Microservices
Compression
~40%Faster rendering
~3×Smaller app size
88–95%Payload compression
~150%Faster data transfer
The problemA high-load Angular application needed faster data rendering, smaller deployed assets, and more efficient service-to-client data transfer across AWS-hosted infrastructure.
ApproachImplemented asynchronous loading, optimized rendering and bundle size, and integrated compression between backend services and client applications to reduce payload size and improve perceived performance.
ImpactImproved perceived performance for users, reduced service-to-client data-transfer overhead, and created a stronger performance baseline for a high-load product environment.
Frontend platform / engineering standards
Reusable Angular architecture standards and project templates
Front-End Tech Lead· 2020–present
Angular
TypeScript
RxJS
NgRx
Code review
The problemAs the product and engineering team grew, new frontend projects needed consistent architecture, modern dependencies, secure defaults, and predictable review workflows.
ApproachAudited codebase and infrastructure risks, selected modern frontend libraries, defined Angular project architecture, coding guidelines, review practices, and reusable templates; supported onboarding through mentoring, code reviews, and knowledge-sharing materials.
ImpactImproved frontend consistency across projects, reduced architectural drift, and established a stronger technical foundation for faster onboarding and safer feature delivery.
Experience timeline
floLIVE2020 – present
Senior Full-Stack Engineer / Frontend Tech Lead
Own frontend architecture modernization, reusable project standards, and engineering consistency across product teams.
Build and improve high-load product systems with Angular, TypeScript, Kotlin, Spring Boot, Kafka, and event-driven microservices.
Mentor engineers, review architecture and code, support onboarding, and improve delivery workflows through reusable practices.
Helped build a low-code/no-code platform from 0→1, moving from early product concept to a production-ready system.
Contributed during the startup-to-scale phase connected to a $21.5M raise and merger with floLIVE.
INETEX Computing Solutions2017 – 2018
Frontend Developer
Built web applications, APIs, and user interfaces for data-processing, operational, logistics, and monitoring products.
Applied research, mentorship, and public proof
Beyond day-to-day product engineering, I build public proof through applied research, technical writing, mentorship, and judging. My focus is practical software engineering: Developer Experience, AI-assisted Dev-QA, microservice efficiency, frontend architecture, system design, and engineering productivity.
Looking for a senior engineer who can build, scale, and modernize product systems?
I’m open to U.S.-based senior engineering and technical-leadership opportunities where I can help product teams build, scale, and modernize high-load systems without sacrificing architecture, reliability, or maintainability.