Backend systems
Secure architectures for identity, KYC, payments, financial operations, audit tooling, real-time systems, and high-availability APIs.
Available for selected engineering engagements · Istanbul
Build the hard parts.Keep them running.
I’m Samed Kahyaoğlu, an independent senior full-stack engineer and former tech lead. My strongest work is architecture and secure backend engineering, but I also handle frontend implementation and UI/UX. Previously, I led engineering at a regulated crypto exchange across identity, compliance, exchange infrastructure, and audits. I build and lead teams and work across product, design, operations, finance, compliance, and company leadership.
Full-stack web engineering
What I bring to a team
I can work across a whole product. My strongest areas are backend systems, architecture, and technical leadership.
Full-stack products
UI/UX, frontend, backend, data, infrastructure, and deployment handled as one product build.
Production AI
Agents, retrieval, workflow automation, evaluation, and observability integrated into real products and operations.
Technical ownership
I stay close to the code while helping with architecture, delivery, hiring, and technical direction.
Selected work
Systems I have taken ownership of
A few products and systems where I was responsible for both the code and the decisions around it.
05 projects
Selected systems
1 / 2
An operational monitoring platform for teams running scheduled and event-driven workloads. I co-built the product end-to-end: job monitoring, uptime visibility, incident timelines, routed alerts, public status pages, and AI-assisted setup. It is live in production with alerting, incident tracking, and status pages.
Architecture
Split ID and Beats services with BullMQ workers behind a React operations dashboard.
Built with
- React 19
- Vite
- TypeScript
- Express 5
- PostgreSQL
- Prisma
- Redis
- BullMQ
- OpenTelemetry
- Coolify
A practice-management product for clinical psychologists in Türkiye. It brings appointments, reminders, notes, client records, and clinic workflows into one place, developed around Turkish compliance requirements and the professional ethics of clinical practice. It is in development, and we are learning from psychologists before launch.
Architecture
Turborepo monorepo with a NestJS API, Next.js app, and opt-in BullMQ mail worker.
Built with
- Next.js 16
- NestJS 11
- TypeScript
- PostgreSQL 16
- Drizzle ORM
- Redis 7
- BullMQ
- ts-rest + Zod
- Docker
- Coolify
Led BiLira’s transformation into a regulated crypto exchange, including the simultaneous launch of the new platform and retirement of legacy systems while working with independent auditors and government bodies. The licence application was submitted ahead of competitors with a lean engineering team.
Architecture
Regulated exchange platform spanning identity, trading, operations, and audit surfaces.
Built with
- Node.js
- TypeScript
- React
- KYC/AML
- Exchange infrastructure
02 projects
Other selected work
A focused modernization for a legacy industrial supplier: product information reorganized and improved with AI while retaining the site’s existing search visibility. The result was 90% faster page loads with legacy SEO retained and a clean source code handoff.
Architecture
Static-first App Router catalog with file-based content, PDFs, redirects, and SEO artifacts.
Built with
- Next.js 16
- TypeScript
- Tailwind CSS 4
- shadcn/ui
- Base UI
- Static generation
- Sharp
- PDF delivery
- Structured data
- Coolify
2022 · Blockchain Developer
Yumak
An ERC-20 token platform with centrally orchestrated circulation and automated grant distribution through a fiat ramp, designed for transparent scholarship tracking. The product shipped, although the company and product were later discontinued.
Architecture
Flask service with PostgreSQL data and EVM token rails for grant distribution.
Built with
- Python
- Flask
- Web3
- Solidity
- PostgreSQL
Samed Kahyaoglu, Istanbul
Background
Technical leadership, still close to the work
I started as the first non-founder engineer at a fintech and went on to lead engineering at BiLira through its transformation into a regulated crypto exchange. Along the way, I built identity and KYC platforms, banking and blockchain rails, and the audit tooling that regulation demands. I have since expanded across frontend implementation and modern UI/UX, so I can carry a web product across the full stack.
I was the primary technical contact for MASAK, SPK, and independent financial audits across three fiscal years, and directed the TÜBİTAK and MKK integrations required for exchange licensing. I also hired and led engineers and coordinated delivery across product, design, operations, compliance, finance, auditors, regulators, and company leadership.
Timeline
Experience
2026 – present
Senior Full-Stack Engineer
Lucky S Software
Lucky S Software is where I build my own products and publish this blog. Most of my work here has been product development, with occasional software consulting for companies in my close network.
- Co-built and launched Drumbeats.io, an operational monitoring product for software teams.
- Building İyi Seans, a practice management product for psychologists.
- Advised companies in my close network on software decisions and helped improve their infrastructure.
2023 – 2026
Tech Lead
BiLira
Led engineering through BiLira’s transformation from a stablecoin issuer into a regulated crypto exchange, balancing product delivery with regulatory and operational requirements.
- Personally wore the product-manager hat across multiple projects for a 1–2 year stretch, owning scope, priorities, requirements, and delivery alongside the engineering work.
- Grew the team across hiring cycles and doubled delivery throughput by restructuring workflows around sprints, kanban, and technical grooming.
- Primary technical contact for MASAK, SPK, and independent financial audits across three fiscal years.
- Built the first automated independent-audit tooling after SPK III-35B.1, later adopted by multiple companies in Türkiye’s crypto ecosystem.
- Directed TÜBİTAK and MKK integrations and architected compliant stateless service infrastructure for exchange licensing.
2022 – 2023
Software Developer
BiLira
Built the platform behind the token: identity, banking rails, circulation services, and the internal tools that operations relied on.
- Architected the core Node.js and PostgreSQL API managing stablecoin circulation with high availability.
- Built BiLira ID with OAuth 2.0, SSO, and KYC, then migrated the full legacy user base through it.
- Developed back-office tools and transaction automation that removed operational bottlenecks.
2021
Software Developer
Stey Financial Technologies
Moved from research into production engineering on the company’s financial products.
- Led development of trading software in TypeScript.
- Built aggregated order books using WebSocket and REST APIs from major exchanges for optimal price fulfillment.
2020 – 2021
Blockchain Developer & Researcher
Stey Financial Technologies
First non-founder engineer, turning blockchain infrastructure research into working product prototypes.
- Designed Web3 product architectures and built cross-chain ERC-20 tokens on EVM networks.
- Developed YUMAK, a Python, Flask, and Web3 application for transparent grant distribution.
Long-form notes on software, AI, and the changing economics of building products.
All posts
Contact
Looking for a senior engineer who can own the work?
Tell me what you are building, what is difficult, and where you need leverage. I’m a good fit for an important build, a difficult modernization, an AI capability that has to work in production, or a team that needs senior technical direction. I reply within two working days.