Senior Product Engineer
OleksandrKukhtin
I build interfaces that hold up under real production load — media tooling at Netflix, AI writing surfaces at Writer, and commerce systems for millions of users. When a feature needs a simple backend, I can write the Node/Express/Postgres CRUD layer for it; large-scale distributed backend design is not my specialty.
- Based
- Warsaw, Poland · Remote preferred
- GitHub
- github.com/alexisinwork
- linkedin.com/in/alexkuhtin
12+
years shipping product UI
20%
fewer incidents and bugs at Netflix
30%
manual steps removed by automation
32%
less agent time per customer at Tourlane
01 · Edge
What sets me apart from other UI engineers
Six things I bring that most frontend candidates do not — each one is demonstrable on this site, not a bullet on a slide.
- 01
Frontend ownership with backend support and product/UX thinking
I primarily own the UI and can write the basic Node/Express endpoints and PostgreSQL tables a feature needs. I also handle the product-management side — requirements, scope and delivery — and my earlier career as a UX designer means deep, fluent collaboration with Design and PM instead of hand-offs.
- 02
Performance treated as a product feature
This site ships its own live Web Vitals panel — LCP, CLS, INP measured in your browser, with the exact techniques used listed underneath. I hold the same budgets in production code.
- 03
AI engineering, certified and applied
AI Engineering Basics certified, with real work in RAG, embeddings, evals, tool calling and MCP — plus daily use of Claude Code, Codex, Antigravity and Kimi K3 as an engineering harness.
- 04
I build my own tools
The interview trainer and AI roadmap on this site are tools I built for myself and kept maintaining — hundreds of questions, a sandboxed code runner, and a learning graph, all self-hosted here.
- 05
Security and accessibility by default
Strict headers, sandboxed execution, server-side rate limiting, secrets never in the browser, keyboard-complete UI and honest semantics — checked, not claimed.
- 06
Netflix-scale production instincts
20% fewer incidents and 30% fewer manual steps on tooling used by thousands of productions. I optimise for the on-call engineer as much as the end user.
02 · Experience
Twelve years of shipping product interfaces
Senior Product Engineer with 12+ years building scalable, user-centric web applications for product teams at Netflix, Writer, HelloFresh, Zalando and Tourlane. I am primarily a frontend specialist; I can also build the basic Node.js, Express and PostgreSQL CRUD services and backend-for-frontend layers a feature needs, but I am not a distributed-systems backend engineer. I specialise in thoughtful user experience, robust frontend architecture and remote-first, transparent engineering — async workflows, sharp documentation, and no-ego code review.
Netflix
Senior UI Engineer (Frontend)Aug 2023 — Present · Warsaw, Poland (on-site)- Redesigned and developed internal drive-based workflow tools, improving file upload/download efficiency for thousands of productions, reducing incidents and bugs by 20% and manual steps by 30% through automation.
- Re-architected the backend-for-frontend layer, migrating from Node.js/Express to a Netflix-internal BFF solution and doubling system observability and monitoring capability.
- Built and maintained Node.js services and GraphQL/REST endpoints over relational (PostgreSQL) and internal data stores, owning schema changes, migrations and query performance.
- Developed a video diffing tool that visually surfaces differences between video file versions in media players and timelines, streamlining quality assurance.
- Collaborated cross-functionally with Design, Product and Support to understand user needs and ship impactful improvements.
- Championed clear asynchronous communication, documentation, and no-ego code reviews focused on clarity and shared learning.
- React
- TypeScript
- GraphQL
- Node.js
- Express
- PostgreSQL
- Jest
- Sentry
- Jenkins
- Git
- SRE
- AI-First Development
Writer
Senior Frontend EngineerDec 2021 — Jul 2022- Engineered an AI-powered writing assistant for teams: terminology management, writing rules and dynamic style-guide enforcement.
- Designed and implemented a custom Quill-based AI-assisted editor highlighting grammar, clarity and compliance issues in real time.
- Built and maintained the CMS for user and team management, supporting scalable collaboration and admin workflows.
- Extended Node.js/Express API endpoints backing the editor and admin surfaces, including data modelling in PostgreSQL.
- React
- React Hooks
- TypeScript
- Node.js
- Express
- PostgreSQL
- Lerna
- Jest
- GitHub Actions
HelloFresh
Senior Frontend EngineerDec 2020 — Jan 2022- Owned delivery of critical updates to the Delivery History feature serving millions of users.
- Consolidated three internal CMS systems, streamlining menu publishing, recipe editing and menu creation.
- Led requirements gathering, user stories, delivery coordination and documentation for multiple high-impact features as Delivery Lead.
- Interviewed frontend candidates and drove async transparency across stakeholders.
- React
- Redux
- React Query
- TypeScript
- Cypress
- Testing Library
Tourlane
Senior Frontend EngineerJun 2019 — Nov 2020- Delivered internal productivity tools that cut agent time per customer by 32% and raised customer satisfaction.
- Built MVP frontends for backend teams, accelerating new app launches and integration across Backend, Product and Design.
- Wrote Node.js/Express service and BFF endpoints with PostgreSQL-backed data to unblock frontend delivery.
- Applied TDD throughout and kept cross-functional communication open and explicit.
- React
- JavaScript
- Node.js
- Express
- PostgreSQL
- Styled Components
- Cypress
- TDD
- GitHub Actions
Zalando SE
Frontend EngineerMar 2016 — May 2019- Developed an application that streamlined campaign setup for advertising managers, increasing team capacity and contributing to revenue growth.
- Migrated the legacy platform from Angular to React, improving performance and maintainability.
- Mentored junior developers and aligned OKRs with UX, Product Management and leadership.
- JavaScript
- React
- Angular
- Redux
- CSS
- Jenkins
- Protractor
Freelance
Frontend Engineer (Remote)Feb 2015 — Feb 2016- Built client-facing web applications end to end, from requirements to delivery.
- Introduced component-driven architecture and end-to-end testing to small product teams.
- JavaScript
- React
- Angular
- Redux
- CSS
- E2E Testing
03 · Toolkit
What I work with
Core
- React
- TypeScript
- JavaScript
- React Hooks
- Redux
- React Query
- GraphQL
Craft
- Design systems
- Accessibility
- Animation / motion
- Styled Components
- Tailwind CSS
- Web performance
Quality
- Jest
- Cypress
- Testing Library
- Protractor
- TDD
- Sentry
Backend
- Node.js
- Express
- REST APIs
- GraphQL servers
- Backend-for-frontend (BFF)
- PostgreSQL
- SQL & schema design
- Migrations
- Auth & sessions (JWT/OAuth)
- Docker basics
Platform
- Electron
- Webpack
- Vite
- Jenkins
- GitHub Actions
- Git
- SRE
- Observability
AI
- LLM APIs
- AI-First Development
- Model Context Protocol (MCP)
- Tool calling
- RAG & embeddings
- Chunking strategies
- Evals
- Prompt engineering
- Claude Code
- Codex
- Antigravity
- Kimi K3
- Cursor
Leadership
- Mentoring
- Project management
- Requirements & delivery lead
- Hiring & interviewing
- Async documentation
04 · Backend
Ship features end to end
I own features end to end — I don't stop at the hand-off line. When a feature needs an API, I build the Node.js/Express layer behind it — CRUD endpoints, PostgreSQL schemas, migrations and auth — enough to ship the whole thing myself. Beyond that I hold a working, conceptual understanding of the wider backend and infrastructure landscape (Python, SQL, Docker, Terraform, Kafka, Kubernetes). Where I add most value is the product surface — I take backend work where a feature needs it rather than as a standalone brief.
Node.js & Express services
REST and GraphQL endpoints, backend-for-frontend layers that shape data for the UI, request validation and structured logging. Not production backend architecture at scale.
- Express routing
- BFF pattern
- Zod validation
- CRUD
PostgreSQL & data modelling
Relational schema design for small-to-medium features, migrations, query performance and pragmatic row-level access rules.
- Schema & indexes
- Migrations
- Query performance
- Row-level security
Production concerns
Auth and sessions, rate limiting, Docker-based local parity, and enough tracing to keep frontend features observable. I do not design distributed queues, caches or orchestration.
- JWT / OAuth
- Rate limiting
- Docker
- Tracing
Broader stack — conceptual level
I understand conceptually how the surrounding infrastructure works — Python, SQL, Terraform, Docker, Kafka, Kubernetes — enough to read the code, reason about the architecture and collaborate with backend and DevOps teams. I am not the person who designs or operates these systems.
- Python
- SQL
- Terraform
- Docker
- Kafka
- Kubernetes
05 · AI engineering
My path into AI engineering
The pipeline I follow when I take an AI feature from idea to production — from picking a model and its pricing strategy through chunking, embeddings, RAG, evals and shipping.
AI Engineering Basics
Certification · passed · 2026
Model selection, prompt and context design, embeddings, chunking, retrieval-augmented generation, evaluation and deployment trade-offs.
- 01
Frame the task
Define the job before the model: inputs, outputs, latency budget and the eval that proves it works.
- Use case & constraints
- Golden test set
- Success metric
- 02
Choose the model
Match capability to task — reasoning depth, context window, multimodality, tool calling and licensing.
- Frontier vs small model
- Context window
- Tool calling support
- 03
Pricing & hosting strategy
Decide where inference runs. Managed public APIs win on speed to market; open weights win on unit cost, privacy and control at volume.
- Public API (per-token, zero ops)
- Serverless inference provider
- Open-source weights self-hosted / local
- Cost per 1M tokens vs GPU hour
- Caching & batching to cut spend
- 04
Prepare the knowledge
Ingest, clean and chunk source documents so retrieval returns coherent, self-contained context.
- Parsing & cleanup
- Semantic vs fixed chunks
- Overlap & metadata
- 05
Embeddings & vector store
Embed chunks, index them, and pick a store that fits scale and filtering needs.
- Embedding model choice
- Vector index (HNSW / IVF)
- Hybrid keyword + vector
- 06
RAG retrieval
Retrieve, re-rank and compress context, then ground the answer with citations and refusals.
- Top-k + re-ranking
- Context compression
- Grounded citations
- 07
Orchestration & tools
Wrap the model in typed tools, structured output and agent loops with hard limits.
- Function / tool calling
- Structured output schemas
- Step & cost limits
- 08
Evals & guardrails
Score every change against the golden set, and keep prompt injection, PII and jailbreaks out.
- Offline evals
- LLM-as-judge
- Injection & PII filters
- 09
Ship & observe
Stream responses, rate limit per user, trace every call and watch quality, latency and spend in production.
- Streaming UX
- Rate limiting
- Tracing & cost dashboards
06 · Side builds
Tools I built for myself
07 · Peer reviews
What colleagues say
Public LinkedIn recommendations, plus anonymous 360° feedback where names and companies are withheld and only the reviewer's role is shown.
“It is not everyday you come across someone like Oleksandr who brings in enthusiasm when you engage in a conversation. I had the pleasure to work with Oleksandr in HelloFresh, where he was responsible for Frontend development. Collaborating with him was a pleasant experience and the turn around times were quick in the project where we both worked together as Frontend / Backend engineers. He also displayed his leadership capabilities when he was leading stand ups and meetings related to project initiatives. Oleksandr's documentation skills is also something that cannot be overlooked. His skills as an author is reflected in his documentation work making even the most boring documentation a pleasure to read. Oleksandr would be a great asset both as a team member and leader.”
“I had the pleasure of working with Oleksandr as a Senior Front-end developer on my team. He was an invaluable asset to the team with his proactive, kind, and responsible position. He always had a great attitude and positive thinking, which made working with him a pleasure. I highly recommend him to any team looking for a skilled and dedicated Front-end developer.”
“It was a pleasure working with Alex, as he's a bright and smart individual, it's easy to work and communicate with him, he brings in positivity and good mood. He's a team player as well as a self-sufficient and reliable engineer, keen for learning and personal growth, open to any challenge. He cares about what he's building and who he's building it for, so you can expect high quality and non-trivial ideas.”
“Alex and I had a great and productive time working together at Tourlane, both as peers and as his direct manager we were able to build CMS-like apps from scratch, as well as improving the existing projects. Working with Alex you can expect a positive and motivated engineer, with good communication skills and confidence in his abilities to overcome any requirement you send his way!”
“I was Oleksandr's direct manager in Zalando. During his time in our team he demonstrated a unique ability to solve issues with a great speed and quality. He is self motivated, technically skilled and fun to work with. He was always keen to learn new technologies and implement them in our tools. It was a great pleasure to work with him and I would be happy to do it again.”
“I have absolutely enjoyed working with Oleksandr. He's a smart software engineer, great team player, doesn't shy away from tackling complicated engineering issues. Oleksandr is one of those developers who is able to take responsibility for and ownership of a project and implement it from the stage of writing down technical requirements up to the production stage.”
“Very responsive and receptive to requested changes, with frequent communication and a clear desire to get a project across the finish line. Continue to seek as much context as you can from a user/partner to understand the needs.”
“You pull me in at the right moments — not to rubber-stamp something already fully baked, but at points where my input can actually shape the direction. Your TL;DRs were clear, technically precise, and came with a clear recommendation. That combination of proactive check-ins, receptiveness to feedback and clean technical communication is what makes iterative work actually work.”
“Instrumental in piloting a new reliability project: within two weeks you had adapted it to the team's needs and used it successfully in the meeting itself. Your candor in offering constructive feedback and your creativity in suggesting new features made you an exceptional collaborator — and your AI-first playbook gave me genuinely useful insights into my own AI approach.”
“I appreciate your candor and directness. You're leaning into adapting AI and sharing your learnings, and you're not discouraged by mixed feedback — you act on it and improve your approach. You also take care of tech-debt work without any problem, even when it is less visible than feature work.”
“Deep technical knowledge — teammates clearly treat him as the go-to expert on the UI and frontend logic, and colleagues pull him in on hard debugging problems even when he is not officially on call. Fast to act on requests, quick to leverage new AI tooling, and always willing to help even when a question falls outside his area.”
“Your curiosity around AI adoption is something I really appreciate — one of the fastest to embrace AI-first ways of working, and not keeping it to yourself: creating skills and MCPs that make the tooling accessible for everyone. Your selflessness shows too: you organized an on-call practice session and showed the tool to the whole team.”
“Your selflessness stood out right away — proactive, always ready to help, and consistently available to answer questions during onboarding. That kind of support made a real difference in helping me ramp up quickly and feel welcomed.”
“Easy to work with — energetic and willing to discuss and receive feedback while staying humble. Proactive on UI topics and takes the time to explain the process to the whole squad. I also appreciate that you take the time to do an initial analysis before pinging anyone, which narrows down the problem scope.”
“Across several projects you showed a high degree of responsibility. You're very receptive to feedback: you asked how you could improve, listened, and actually implemented it. I really value your candor — you approach even tough topics with the goal of learning.”
“I really appreciated that you wanted to know what was happening in the wider product even though we weren't actively working together. I also really enjoyed our 1:1s — a good space to share context about our work.”
“It's great to see how you take end-to-end ownership of large product areas — internal tooling and quality assurance features. You are iterating directly with stakeholders to get your work production-ready, great job! I also really appreciate your sense of ownership in team review meetings. When nobody is interested in a specific topic you are always stepping up to help.”
“You made the effort to find the right stakeholders, consult with them, and make sure what you built matched their needs. Around the migration initiative you asked thoughtful questions and actively tried to understand the space better, which made our collaboration smoother. You took in feedback on your AI approach and adjusted how you use it, surfaced findings early to create a quick feedback loop, and made good calls by looping in all relevant parties to avoid surprises later. You listened, reflected, and adapted your way of working — that willingness to adjust for the benefit of the team really stands out.”
“One of the things I appreciate most is the growth you have gone through over the last year — project ownership, daily execution, visibility, and overall proactiveness. You acted on feedback after the quality-tooling project, translated it into meaningful improvements, and successfully drove a large content-review migration while working directly with stakeholders — a significant step forward in your ability to lead and deliver complex initiatives. You also took ownership of a separate platform integration autonomously, investing effort beyond your regular responsibilities. From a culture perspective you are very easy to work with: approachable, open to feedback, and equally willing to provide feedback to others.”
“It's been a real pleasure working with you on the tooling projects! You're not afraid of unknown challenges — you were one of the first people to integrate into the shared tool library when developing a new application, and your feedback helped us shape the platform rather than blindly guessing. You also share your approaches regarding AI-native work and project/code organization, which multiplies your expertise across projects and people.”